THR Group Project - PISTOL - Advanced Reloading Concepts and Discussions

[LiveLife]

- CASE WALL FAILURE/RUPTURE - BULLET SETBACK/POWDER COMPRESSION

Follow up post - http://www.thehighroad.org/showthread.php?p=10123284#post10123284

40 Glocks go kaboom all the time. Unsupported chamber.

internet folklore

I have reloaded/shot several hundred thousand rounds in Gen2 and Gen3 40S&W Glocks and have seen plenty of KaBooms (KB) personally. I started USPSA match shooting in mid 1990's and when a 1911 KaBoomed, many seasoned match shooters talked about KaBooms predating Glocks by decades and talked of various 1911s/High Powers/Berettas blowing up. Several KaBooms I have seen with damages to pistols and shooters have been with non-Glock pistols. Yes, reloaders have been blowing up pistols long before Glocks as double charges existed long before Glocks.

As to 40S&W Glocks going KaBoom all the time ... well, A LOT of 40S&W Glocks have been sold over the decades and if a KaBoom occurred every X rounds of reloads (due to double charge/bullet setback/compressed powder charge/thinned case wall/weakened case wall/etc.), you are simply going to see more Glock KaBooms reported as there are more 40S&W Glocks than other brand 40S&W pistols reloaders are shooting.

While I would agree Gen1/Gen2 Glock 40S&W barrels had more generous chambers with "less" supported case base, by Gen3/ Glock had significantly tightened up the chamber and increased the support for case base. Believe it or not, when I compared my Gen3 Glock barrels to other brand 40S&W barrels (M&P, XD, Sig, etc.), Gen3 Glock barrels had comparable case base support and actually more than some of other brand barrels - But don't take my word, check it out for yourselves and be prepared to be surprised/disappointed.

My decision to use Lone Wolf 40S&W barrels in my Glocks were many but when it comes to case base support, Lone Wolf barrels win hands down. Pictures below show comparison of Lone Wolf 40S&W barrels with Gen3 Glock barrels. You cannot see the forward part of the Glock chambers which are tighter than Gen1/Gen2 chambers but the case base support of the chamber mouth is comparable to most other brand factory 40S&W barrels. However, the Lone Wolf barrels provide more supported chamber mouths to insure against case base blowout and it is one of many reasons why I use 40S&W Lone Wolf barrels in my Glocks.

Close up of Glock vs Lone Wolf barrels at chamber mouth

What I found using Lone Wolf barrels with tighter chambers is that my brass don't expand as much and resizing them takes less effort (see comparison pictures below). This tells me that I am working my brass less/reducing work hardening thus keeping the brass malleable longer. When other reloaders compare my brass from Lone Wolf barrels to their overly expanded brass, they get alarmed with worries of thinning of case wall. I tell them if they are concerned, to reduce the powder charge or change powder and the case expansion decreases.

Picture shows expanded case shot in a non-Glock chamber as indicated by non-Glock primer impression

While this is a picture of a resized brass, brass shot in Lone Wolf chamber resemble this brass with flat case base that takes less effort to resize indicating less case wall expansion (perhaps less case wall thinning) and result in less working of brass to extend malleability and case life.

 

[LiveLife]

- METERING SMALL POWDER CHARGES CONSISTENTLY WITH PAD

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10135728#post10135728

Measuring light loads for 380 ... Lee pro 1000 with the auto disk powder measure. Since it bottoms out at ~2.8 gr of Bullseye I'm looking for a way to load lighter (2.1-2.5) loads ...

I went with adding a machine screw to the existing disk to shrink the cavity. It works ok, but I get a little variation in the charges (+/- .1gr) with a few off by about .2gr. Could be my scale. Or maybe some powder piling up on top of the screw and dropping intermittently. I'll probably try adding a taper/polish to the screw end to remove the threads.

In the "Working DIY Micro Auto Disk" thread, brass screw tips were tested unmodified, domed and coned/polished (see above picture) but Bullseye metered/flowed well enough to slide off the threads to provide consistent powder drops (within .1 gr variance) down to 1.5 gr. There was some powder accumulation on top of the threads but it was consistent and didn't see powder bridging to affect powder drop consistency. This level of consistency below 2.0 gr powder charge is as good as you are likely to get from other powder measures - http://www.thehighroad.org/showthread.php?p=9318360#post9318360

I think the variation you are seeing could be the scale or the stacking of variance of scale and the variance from powder drop. To verify accuracy/consistency of scale to .1 grain, check weights should be used but if you don't have check weights, cut a clean sheet of 20 lb copy paper into 1/4"x1/4" pieces and using tweezers (to prevent contamination) place the piece of paper on the scale to see if it is detected (you can place a glass bowl over the scale to block out the affects of air movement or close door/air vents). Two pieces of paper should weigh around .1 gr and if your scale cannot consistently detect and weigh .1 gr repeatedly, you may not have a scale that is accurate to .1 gr - http://www.thehighroad.org/showthread.php?p=9596742#post9596742

With some powders like Titegroup, which has crinkled textured surface instead of smoother surface like W231/HP-38/WSF/AutoComp (see comparison picture above), granules locked together and inconsistently accumulated on top of the threads and/or bridged instead of flowing and using rounded/polished tip allowed Titegroup to meter consistently down to 2.5 gr.

As comparison pictures below show, rounding and polishing the tip did not significantly improve the performance of this mod as the tip needed to be screwed in more to make up the volume inside the disk hole and this increased the issue of powder accumulation on top of the tip and/or bridging. With small granule powders like Bullseye/BE-86/Power Pistol/W231/HP-38/WSF/AutoComp etc., I do not think modification of the tip is necessary to meter above 2.0 gr powder charges.

 

[LiveLife]

- POWDER TYPES (Shape/Burn rate/Coating)

Continued from Post #171 - http://www.thehighroad.org/showthread.php?p=10094185#post10094185

Updating the listing of powders by "relative" burn rate with Vectan, Shooters World/Lovex and Norma powders.

Vectan by Nobel Sport / Sweden:
- Single base stick powders - Ba10, Ba9 1/2, Ba9, Ba7 1/2, Ba6 1/2
- Single base flake powders - A0, AS, A1

Shooters World/Lovex by Explosia / Czech Republic:
- Single base powders - S011, S015, S020
- Double base powders - D013, D032, D036, D037.1, D037.2

Norma by Ruag / Swiss
- R1, R123, SP2, SP3

Let me know if I need to better position powders on the "relative" burn rate listing:

Faster burning pistol powders:

E3 - Competition - Nitro 100 - N310 - R1 - Ba10 - S011 - D013

No. 2 - Bullseye - Clays - WST - Red Dot/Promo - 700X - TiteGroup - Solo 1000 - Am. Select - International - Trail Boss - PB - N320 - AS - Ba9 1/2 - S015 - D032

No. 5 - W231/HP-38 - Zip - Green Dot - SR7625 - N32C - A1 - S020 - D036

Slower burning pistol powders:

Unique - Universal - BE-86 - Power Pistol - WSF - N330 - Ba9

HS6 - AutoComp - CFE Pistol - Silhouette - Long Shot - Herco - 800X - True Blue - N340 - 3N37 - A0

No. 7 - SR4756 - Blue Dot - N350 - SP2 - Ba7 1/2 - D037.1

No. 9 - Enforcer - W296/H110 - 2400 - Steel - SR4759 - H4227 - Lil'Gun - 3N38 - R123 - SP3 - Ba6 1/2 - D037.2

 

[LiveLife]

- LOAD DEVELOPMENT TO PREVENT COMPRESSED CHARGE

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10190879#post10190879

px4 compact in 40s&w ... Power Pistol ... Xtreme's heavy-plated bullets ...

Lyamn's 49th for 155gr jacketed silvertip, 1.125" OAL says 7.0 starting and 7.8 max and no indication of a compressed load.

The Alliant site for a 155gr Gold Dot shows 9.0gr max, but no indication if it is compressed.

My Lee 2nd edition for 155gr XTP, 1.120" OAL says:
Power Pistol, 7.9c starting and , 9.0c max (the c indicates compressed).

My real concern here is the indication that 7.9g of PP may be compressed with a 155gr bullet. Maybe I'm too concerned about shooting a compressed load, but if I load some at 7.0, 7.2, 7.4, 7.6 gr, is there going to be a compressed load there?

When I conduct load development with a new bullet/powder combination, I always determine working OAL and then max case fill so I know at what powder charge I will start compressing.

To determine max case fill:

1) Determine working OAL/COL

2) Measure several resized cases and bullets

3) OAL - Bullet length = Max case fill (to bottom of the bullet)

4) Then subtract max case fill from case length and measure this number down from case mouth (using the end of calipers) and mark inside the case

5) Fill powder to mark and weigh on scale. This is your max powder charge before you start compressing

OAL ... expect to be slightly longer than what's in the manuals, but I don't know that yet

Using published OAL may not ensure reliable feeding/chambering or produce optimal accuracy. Many factory barrels have longer leade/freebore that will allow more gas to leak before chamber pressures build. While many use published length average of 1.125" to SAAMI max of 1.135" for 40S&W TCFP/RNFP nose profiles bullets, if your barrel's leade is longer, you may need to load longer for more accurate loads.

With 165/180 gr TCFP bullets, I have used up to 1.143" OAL with greater accuracy - http://www.thehighroad.org/showthread.php?p=9362819#post9362819

With 180 gr RNFP bullets, up to 1.155" OAL for more accurate loads - http://www.thehighroad.org/showthread.php?p=9639622#post9639622

I plan on using Xtreme's heavy-plated bullets which are NOT the same as what's in the manuals.

While thick/heavy plated bullets are often rated to 1400-1500 fps, I still prefer to conduct my powder work up using plated or lead load data (if plated load data is not available) instead of using jacketed load data (as you can always go higher) and ESPECIALLY if you are using mixed range brass with unknown reload history and condition of brass.

2004 Alliant load data lists 155 gr lead bullet - http://www.thehighroad.org/attachment.php?attachmentid=182147&d=1364769070

155 gr Lead 1.125" OAL Max 7.0 gr (1,115 fps) 32,300 PSI

150 gr JHP 1.105" OAL Max 8.2 gr (1,215 fps) 33,000 PSI

So if your working OAL is longer than 1.125", I would comfortably use 155 gr lead load data for your plated bullet and use 10% reduction of max of 6.3 gr as my start charge.

And once you calculate the max case fill, you will know what powder charge will start to compress.

 

[LiveLife]

- FINE TUNING USPSA MATCH LOADS

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10208455#post10208455

Which of these three powders for 45acp? unique, bullseye and WST

I cannot find my old standby 45 powder W231 locally.

I'm loading plated 230gr rn and looking to make USPSA major.

bullseye, unique, WST in that order

Unique is about all I use in .45ACP.

I have never seen anyone use Unique for USPSA loads as they are loaded to lighter minor/major PF velocities and Unique doesn't produce consistent enough powder burn/chamber pressures at lower charges. And with 230 gr, you are pushing only 717 fps to meet major power factor which is below start charges for most powders and you will need fast burning powders to produce accuracy at lower charges.

plated 230gr rn and looking to make USPSA major

+1 for HP-38 if you can't find W231.

Out of the three for USPSA major PF loads, I would use WST and Bullseye but not Unique as you only need to push 717 fps for 165 PF (730 fps for 170 PF) which is below start charges at less than 14,000 CUP and not sure if Unique will produce consistent enough powder burn for accurate loads.

But if using WST, keep in mind that WST is reverse temperature sensitive so loads you develop now in colder temperature will shoot slower in hot summer weather so would need to rechrono your loads to meet PF requirements.

Bullseye is temperature sensitive but not as bad as W231/HP-38 so you won't have to worry about meeting power factor requirement as your load will shoot faster in the summer heat - http://www.thehighroad.org/showthread.php?p=10117881#post10117881

Since you are looking for major PF load, you only need 717-730 fps for 165-170 PF and only your chrono will tell you that. Keep in mind the reverse temperature sensitivity of WST so you may need to increase powder charge for warmer seasons and rechrono your loads.

I have used lead load data for plated bullet with good results - http://www.hodgdonreloading.com/data/pistol

230 gr Lead RN WST COL 1.200" Start 4.0 gr (776 fps) 14,300 CUP - Max 4.3 gr (812 fps) 16,400 CUP

For increased accuracy, I would use the longest OAL that will pass the plunk test and reliably feed/chamber from the magazine to reduce gas leakage.

I have found most plated RN bullets to have rounded bullet base which will allow leakage of more gas. With slower velocities to meet major PF requirement of around 717-730 fps, gas leakage will likely make things worse for Unique.

Never meant to imply that I wanted to "just" make major

Would very much like to have a goodly cushion of MV over and above the 717fps needed for Major with a 230gr bullet.

The reasons why many USPSA shooters use match loads that "just" make power factor are many but mostly for faster stage times.

USPSA shooters will quickly find out faster stage times trumps slight edge in accuracy of loads. You don't need bullseye match level of accuracy for action pistol matches but you do need loads that will allow you to double tap faster.

When I was developing my 1911 loads for USPSA, I tested Bullseye/Clays/WST/W231/Universal/HS-6/WSF but settled with W231 because it allowed my sights to return back to the target/POA faster with least amount of effort due to recoil impulse for the recoil spring rate I was using. Bullseye/WST did produce slightly more accurate loads but recoil impulse was different than slower burning W231. Other shooters also suggested I try different rate recoil springs to fine tune my load for faster double taps.

when I've asked for suggestions RE powder and loads, a goodly number of the loads suggested were accurate but "powder-puff" loads that I couldn't really use.

so yeah, got no problem with upper end loads

If you found accurate "powder puff" loads, you could try lower rate recoil springs to make your pistol cycle reliably. The goal is to have accurate loads that meet PF requirement while allowing you to return to target/POA fastest/easier.

This article goes into detail how different recoil spring rates affect cycle time for full power vs reduced power match loads - http://www.shootingtimes.com/gunsmithing/recoil-spring-rate-affects-timing/

 

[LiveLife]

- 9mm RELOADING TIPS

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10232322#post10232322

Is there any tips for loading 9mm?

Due to smaller case volume compared to 45ACP/40S&W, small changes in OAL/COL, bullet seating depth, neck tension, taper crimp (especially for plated bullets) can result in significant change in chamber pressure/accuracy.

LEE makes a 3 die and 4 die set. I have seen some things saying don't use the FC die and use the one in the 3 die set and some say use the FC die.

While I like Lee dies for 9mm, I don't use the Factory Crimp Die (essentially a taper crimp die with larger SAAMI spec carbide sizer ring insert than sizing die carbide ring insert). With jacketed/plated bullets, using the combination seat/crimp die has worked well for me over 20 years and all of my rounds freely drop in the chamber with a "plonk" in various factory and KKM/Lone Wolf barrels.

Some say they like to use the FCD to ensure all the finished rounds will work and I do not see a problem when using .355" diameter bullets with FCD as a "finishing" die which I believe FCD for semi auto pistol calibers was made for. I do have concerns with post sizing when using larger than .356" diameter bullets (especially with thicker walled cases) as bullet diameter will be reduced while brass spring back may decrease neck tension and result in bullet setback when the bullet nose slams on the feeding ramp which can significantly increase chamber pressure.

If there is any concern, you could measure bullet diameter after FCD use and if there is no reduction in bullet diameter, you are good to go. But if FCD reduces bullet diameter and OAL is reduced when fed from the magazine, I would suggest not using the FCD.

I see some post on here about flaring case mouth, etc that I haven't seen in the books. just looking for some advice before I jump in head first into this.

While I prefer to use minimal amount of flare, not using enough flare with softer core bullets can result in bullet diameter reduction which will decrease accuracy. I use enough flare to allow me to set the bullet base just inside the flared case mouth. I have found using plated bullets with harder core (like RMR's 11-12 BHN Hardcore Match bullets) help maintain neck tension which reduces bullet setback.

Amount of flare is dependent on resized case lengths. Longer cases will flare more so measure some cases to determine shorter-to-longer case length range and use flare amount that will work with all of your cases.

I'm looking to load berry's or extreme plated bullets because of the price.

I have used Berry's, HSM, Power Bond, Rainier, RMR, Speer TMJ/Gold Dot, X-Treme plated bullets over the years and found there are two main types: Regular vs thicker plated.

Regular plated bullets have about .004" thickness copper plating and often come with 1200 fps rating. While most pistol loads do not exceed 1200 fps, it means plating won't fail until 1200 fps but your accuracy could fall way before that. I have found when I load beyond mid-range jacketed load data with regular plated bullets, my accuracy starts to fall and shot groups open up.

Thicker plated bullets have .010"-.015" thickness copper plating and often come with 1300-1500 fps rating depending on the thickness of plating. I have found I could use jacketed load data and still maintain accuracy with thicker plated bullets.

If you are looking to load plated bullets for lower price, I would suggest you check out RMR's Hardcore Match bullets. With harder core (11-12 BHN) and thicker plating (.012"-.014"), they maintain neck tension better and I often do not experience bullet setback/reduction in OAL after rounds are chambered. Reloaders are often OCD about OAL but to me, what matters more is "chambered" OAL and bullet setback, especially for small case volume 9mm. I have so far tested RMR HM bullets to mid 1400 fps and they have maintained excellent accuracy - http://www.thehighroad.org/showthread.php?p=10228100#post10228100

RMR also offers 5% THR discount with thehighroad5 code (must also enter THR ID in order comment box) with free shipping on all orders which should help reduce your reloading cost.

Any advice on loading plated vs non plated?

Plated bullets with rounded base leak more high pressure gas which reduces chamber pressure consistency and accuracy. I think for this reason why some plated bullets have concave base and Berry's MFG came out with hollow base bullets to better expand bullet base to seal with the barrel. RMR HM bullets have bullet base rim for this reason.

To improve bullet to barrel fit and better sealing of high pressure gas, some manufacturers like Berry's increased the diameter of the plated bullets and 9mm bullets measure around .3555" instead of .355". RMR HM 100 and 115 gr 9mm bullets are sized even larger at .356" and I believe it helps with gas seal and produces more consistent chamber pressures for greater accuracy.

I often add .020"-.022" to the jacketed bullet diameter to determine the amount of taper crimp but with plated bullets, I will add .022" so as to not cut through the copper plating (.011" being average case wall thickness).

So for .355" diameter bullets:

.355" + .011" + .011" = .377" taper crimp

And for .356" diameter bullets:

.356" + .011" + .011" = .378" taper crimp

Using too much taper crimp with plated bullets can reduce bullet diameter which will cause more gas leakage and inconsistent chamber pressure with poor accuracy.

Also, while we often use longer OAL with 124 gr FMJ/RN (like 1.160") to reduce bullet jump from chamber to start of rifling time to decrease gas leak, with 115 gr 9mm bullets with shorter bullet base, I prefer to use shorter OAL (1.135") to seat the bullet base deeper to increase neck tension. In my carbine load testing, shorter 1.130" OAL improved muzzle velocity consistency and accuracy over 1.160"/1.135" OAL and I am planning to test even shorter 1.125".

I hope this helped.

 

[LiveLife]

- LEAD VS PLATED BULLETS

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10265502#post10265502

I was always under the impression that lead is the cheapest possible option (why I started loading lead). So I found my way over to Xtreme bullets after seeing the name around here a few times and saw their copper plated bullets of the same size being the same price, also pretty much the same price as coated lead bullets from other companies.

When you read the descriptions or do a search you pretty much just get "how their made" but why go one over the other? Copper plated "seems" (to the uneducated bullet guy... me) to be of better quality but there has to be a reason why someone would buy their cast over copper since they cost the same.

School me

Over the decades, I have shot various brand lubed lead bullets, moly coated lead bullets and recently started shooting coated lead bullets. While I have used Montana Gold and Winchester jacketed bullets for match loads, I have used various plated bullets for practice/plinking loads (Berry's/HSM/PowerBond/Rainier/RMR/Speer TMJ/X-Treme).

During past decades, bullets/projectiles improved and evolved. It used to be that jacketed bullets were more accurate and plated bullets were less accurate and if you wanted consistently expanding bullet, JHP was the only choice. Well, things have changed. Copper thickness of thicker plated bullets increased on par with jacketed bullets and many manufacturers like Federal, Remington, etc. started using plated bullets for their "FMJ" factory ammunition - http://www.thehighroad.org/showthread.php?t=706260

As to expansion, for many years, Speer Gold Dot HP bullets have demonstrated more consistent expansion performance than many other JHP bullets. Yes, Gold Dot HP bullets are plated bullets - http://www.speer-ammo.com/products/gold_dot_const.aspx

Lead bullets:

As Schwing and others posted, benefits of lead bullets are lower cost, larger sizing options and greater accuracy. Many factory barrels are oversized and shooting typical jacketed/plated diameter bullets may not produce optimal accuracy from gas leak around the bullet which reduces consistency of chamber pressure which in turn reduces muzzle velocity consistency. Using larger sized lead bullets reduce gas leakage which produces more consistent chamber pressures which results in more consistent muzzle velocities.

Lead bullets also come in various hardness (BHN). I used to use 22-24 BHN lead bullets which claimed they could be pushed to jacketed load data and with proper bullet to barrel fit of .001"+ sizing and not lead the barrel (Well, I always got some leading in my barrels). But now, myself and many reloaders do not load at max load data. For mid-to-high range loads, I have found softer 18 BHN (MBC), 16 BHN (Dardas) and 14-16 BHN (Z-Cast now JacobEagle) lead bullets to deform better to seal with the barrel (obturation) to produce optimal accuracy without leading the barrels. When my oversized Taurus PT145 barrel produced poor accuracy with 18 BHN MBC 200 gr SWC bullet (IDP #1) and got full-length barrel leading, using even softer 12 BHN MBC 200 gr SWC bullet (Bullseye #1) resolved my accuracy and leading issues without having to use larger sized bullets (Since I have multiple 45ACP pistols, especially with tight chambered Sig 1911, using different diameter 45ACP bullets is not a feasible option).

Coated bullets, whether Hi-Tek or powder coated, also depend on the sizing/lead alloy core of the bullets for optimal accuracy but the main benefit is being able to push them at higher velocities (up to 2000+ fps) without leading the barrel.

Plated bullets:

Plated bullets are essentially gas checked lead bullets where the gas check fully covers the bullet. Plated bullets vary in lead alloy core hardness, diameter and copper plating thickness. And not all plated bullets are created equal.

Lead alloy core - If the lead alloy core is too soft, using too much taper crimp can reduce bullet diameter which can reduce neck tension, increase bullet setback and reduce accuracy. RMR lists their Hardcore Match plated bullet alloy core hardness at 11-12 BHN hence "hard" core name. I have found using RMR HM plated bullets with harder core increases neck tension to the point where I am not experiencing much, if any, bullet setback when rounds are slammed against the feeding ramp when fed from the magazine. While many reloaders obsess over finished rounds' OAL/COL consistency, I care more about "chambered" OAL consistency from little to no bullet setback during feeding and chambering.

Bullet diameter - Like lead bullets, plated bullet diameter in respect to groove diameter of the barrel also play a key part in producing accuracy. Most plated bullets are sized to jacketed bullet diameters. Problem with this is most plated bullet bases are rounded and leak a lot of gas. When president of Berry's Manufacturing posted on THR, they experienced accuracy issues with .355" sized 9mm plated bullets. To reduce gas leakage, they sized their plated bullets slightly larger around .3555"+ and accuracy improved and they advertise their 9mm plated bullets as sized .356". RMR sizes some of their 9mm HM bullets larger (like 115 gr RN) and advertises them as .356" - https://rmrbullets.com/shop/bullets...15-gr-rmr-hardcore-match-round-nose-plated-2/

Bullet base - To improve accuracy, Berry's MFG started producing hollow base plated bullets. Intent was to create hollow bullet base that would expand to seal better with the barrel and to extend the bullet base for better engagement with the rifling for greater rotational stability in flight. Many plated bullet manufacturers also use dished or concave bullet base to improve bullet base expansion and RMR uses rimmed bullet base.

Plating thickness - Most jacketed bullets have copper alloy/gilding metal jacket thickness of around .015"-.030". Regular thickness plated bullets have around .004" thick copper plating and are usually limited to 1200 fps. Thicker plated bullets have .012"+ thick copper plating and are usually limited to 1500 fps. Below is a listing of copper thickness of various plated bullets as best as I could find - http://www.thehighroad.org/showthread.php?p=9927091#post9927091

Speer TMJ: .015"

Rocky Mountain Reloading HM: .012"-.014" (rated to 1500 fps)

Berry's Thick Plated (TP): .012" (rated to 1500 fps)

PowerBond: .010"-.011" (rated to 1300 fps)

Berry's Regular: .0035"-.008" (rated to 1250 fps)

Hunting Shack Munitions: .005" (no fps rating)

Rainier Ballistics: .004" (rated to 1500 fps?)

X-Treme: Can't find any reference for plating thickness but rates the regular plated bullets to 1200 fps and "Heavy Plate Concave Base" plated bullets to 1500 fps

Frontier CMJ: Can't find plating thickness or fps rating


So why choose plated over lead?

For me, using plated bullets reduce exposure to lead and use of thick plated bullets allow me to use cheaper bullets for carbine loads.

The THR Lead Poisoning thread addresses hazards of lead exposure and my personal experience - http://www.thehighroad.org/showthread.php?p=9625420#post9625420

I am currently fine tuning 9mm carbine loads to replace 22LR plinking ammo at comparable cost and RMR HM 100 gr RN bullets allow me 1450+ fps loads that produce around 1.5"-2" groups at 50 yards using mixed range brass - http://www.thehighroad.org/showthread.php?p=10245856#post10245856

With THR 5% discount, I can buy 1000 RMR HM 100 gr RN for $72.20 with free shipping which brings down the cost of reloading 50 9mm carbine rounds under $6 (BTW, THR 5% discount code for RMR is thehighroad5 and you need to enter THR ID in the order comment box).

 

[egd]

I've been watching the carbine testing thread for more range reports about the 100 gr bullets. Since you mention it here, do you find the 100 gr perform better than 124 gr in your carbine? I've just had my carbine (colt 6951) a few weeks now and I've been shooting the same as my pistol loads in it. They seem to do well, but 40 yds is all I have been able to shoot so far. I have been using the RMR 124 plated RN. I'd kinda like to keep using the same ammo in both, but if the 100 gr perform noticeably better I'd load them for the carbine. Your thoughts???

 

[LiveLife]

- TRANSONIC EFFECT ON ACCURACY

egd, for years there's been talk of transonic effect on bullet accuracy where supersonic bullet in flight experienced "turbulence" as bullet slowed down to subsonic speed. Due to this reason, many suggested we either load so bullet stays above 1126 fps to target or keep muzzle velocity below 1126 fps.

While I initially tested my carbine loads using 115/124 gr bullets with inconclusive range results, I noticed more bullet drop from heavier and slower 124 gr loads as bullets "arced" on arched trajectory to target. Walkalong suggested I test lighter bullets which would produce faster flatter trajectory that would be less affected by transonic effect. I had 95 gr Montana Gold JHP, 100 gr RMR HM RN and 100 gr X-Treme RNFP but since the carbine load thread was for plated bullets, RMR 100 gr HM RN was the only bullet I had that was rated to 1500 fps for range testing.

As suggested by Walkalong, 100 gr bullet staying supersonic to 50 yard target (~100 fps reduction for each 50 yards traveled) produced tighter groups with my reference W231/HP-38 powder and even with Promo.

Initial range test with 100 gr RMR HM RN loads produced below chrono results and 50 yard shot groups as compared to 115 gr RMR HM RN (both loads should have remained above 1126 fps to target):

100 gr RMR HM RN 5.2 gr HP-38: 1459-1424-1423-1465-1413 fps
115 gr RMR HM RN 4.8 gr HP-38: 1275-1263-1253-1290-1248 fps

With promising initial range test, I increased the powder charge for the next range test and got the following results:

5.5 gr HP-38: 1493-1468-1432-1479-1454 fps
4.5 gr Promo: 1442-1428-1478-1431-1462 fps

For the next range test, I further pushed the powder charge for Promo and got smallest chrono variation so far:

100 gr RMR HM RN 4.5-4.7 gr Promo: 1478-1475-1480-1471-1467 fps

At this point in my testing, I am quite happy with the Promo load results and will next work on HP-38 load by working down to 5.2 gr from 5.5 gr.

As to future 124 gr load testing, I will likely test subsonic loads to avoid the transonic effect.

 

[egd]

OK, thanks. I look forward to your testing of some 124. FWIW, here is some results I got with my only shots through a chrono with my carbine, I tested all my loads I have worked up for my pistol. All are at an oal of 1.135 to 1.140, my usual variance.All are 8 shot strings except for the BE-86 which only read 5 of the shots. All with the RMR 124 gr RN plated.
WSF-4.5 gr avg.1179.9 (one weird low shot though, so??)
BE-86-4.9gr avg 1253
231/hp38-4.2 gr. avg.1188.2
AA5- 5.9gr. avg. 1250
CFE pistol-5.1gr. avg 1293

 

[LiveLife]

- MUZZLE VELOCITY CONSISTENCY OF POWDER VOLUME VS CHARGE WEIGHT

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10268900#post10268900

Could this theory be true? Could it be true for some powders and not for others? What are your thoughts?

Powder volume is more consistent than a weight measurement in regards to muzzle velocity of a round, all other factors being the same.

I think it would depend on powder and charge/case fill used.

To me, consistency of muzzle velocity is directly dependent on consistency of chamber pressure and consistent chamber pressure is dependent on:

- Powder charge consistency
- Case fill that minimize air space/contact with primer for more efficient powder burn when primer ignites
- Amount of gas leakage which is dependent on bullet type/base construction, bullet diameter relative to groove diameter of the barrel, leade/freebore length and
- Bullet seating depth which is dependent on
- OAL/COL of "finished rounds" and "chambered rounds" after bullet nose slams against the feeding ramp and produces
- Bullet setback which is dependent on
- Neck tension which is dependent on
- Amount of sizing/diameter of bullet/bullet base length/amount of bullet seating depth and
- Condition of brass as to how much work hardening experienced which is dependent on number of firing, amount of flaring used, amount of taper crimp used, how brass was processed and stored, etc.

all other factors being the same

In theory, this could work but since most of us use range brass, only using new brass will reduce brass related variables like neck tension, bullet setback, chambered OAL and chambered bullet seating depth.

I am currently fine tuning my 9mm carbine loads to produce as much consistent muzzle velocity as possible using range brass so bullet drop at 50/100 yards is minimized. OAL is controlled down to around .001"-.002" variance and chambered rounds are checked for bullet setback.

I am using W231/HP-38 as my reference powder which meters with less than .1 gr variance from my modified Pro Auto Disk and produced following chrono numbers - http://www.thehighroad.org/showthread.php?t=741988

100 gr RMR HM RN 5.2 gr HP-38 @ 1.050": 1459-1424-1423-1465-1413 fps
100 gr RMR HM RN 5.5 gr HP-38 @ 1.050": 1493-1468-1432-1479-1454 fps
100 gr RMR HM RN 4.5 gr Promo @ 1.050": 1442-1428-1478-1431-1462 fps
115 gr RMR HM RN 4.8 gr HP-38 @ 1.130": 1275-1263-1253-1290-1248 fps

These test loads were essentially 90-95% case fill loads with less than .1 gr powder charge variance (Promo charges were weighed). But surprise came when 100% case fill and metered by volume loads of Promo with .2 gr variance were chronoed:

100 gr RMR HM RN 4.5-4.7 gr Promo @ 1.050": 1478-1475-1480-1471-1467 fps

13 fps is the smallest velocity spread I have yet to see during my carbine load testing, even with .2 gr variance charge to charge!

So for my test loads and 9mm carbines, same volumetric powder charge load shot more consistent than same powder weight charge load which produced below 10 shot groups at 50 yards - http://www.thehighroad.org/showthread.php?p=10245856#post10245856

 

[egd]

LOL,LOL--depends upon-depends upon-depends upon.... Wow, if a newbie reads this he'll think it's a wonder we get anything to be slightly consistent.
But it's all true though.

 

[LiveLife]

- RELATIVE / COMPARABLE POWDER BURN RATE

Continued from post #178 - http://www.thehighroad.org/showthread.php?p=10163949#post10163949

Updated with more Explosia Lovex (Shooters World) powders and shuffled some more powders by relative burn rate - http://shootersworldsc.com/propella...0MP - Winchester W296/H110 and Vectan Ba6 1/2

 

[LiveLife]

- OAL CONSIDERATION FOR 9MM

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10298630#post10298630

What is the downside to reloading 9mm with a lengthy OAL

I load various 9MM 115 and 124/5 Gr RN bullets at 1.130 to 1.135 OAL. (Although I have one I load at 1.140/45)

The other consideration is enough bullet inside the case to ensure it's firmly held.

+1 to Walkalong/rodregier's comments.

Downside to loading 9mm long is reduction in neck tension and chamber pressure build, especially for 115 gr FMJ/RN bullet with shorter bullet base and particularly .355" sized plated bullets with rounded bullet base which leaks more gas and this problem gets worse with slower burning powders at lower powder charges.

Many reloaders complain 9mm is more difficult to reload accurate than other calibers like 45ACP. This may be due to smaller case volume that is more affected by reloading variables not so much noticed in larger case 45ACP.

When primer ignites powder, there are several factors to consider to produce more consistent chamber pressures which leads to more consistent muzzle velocities that results in lower SD number:

- Powder case fill/powder position in relation to primer flash
- Powder charge/load data vs powder burn rate
- Initial powder burn and chamber pressure build from neck tension/bullet seating depth
- Continued chamber pressure build from case neck/mouth expanding to seal with chamber
- High pressure gas leakage as bullet jumps through leade/freebore to start of rifling
- Max chamber pressure build from bullet's bearing surface engaging the start of rifling

With 115 gr FMJ/RN bullet, while longer OAL/COL will reduce gas leakage from shorter jump to start of rifling, it's been my experience that reduction in neck tension/chamber pressure build can overshadow gas leakage if using powder charges less than near max and/or using slower burn rate powders.

With 124 gr FMJ/RN bullet, this is less of an issue due to longer bullet base and I will often use longer 1.150-1.160" OAL to reduce gas leakage and to reduce powder charge compression but prefer to use shorter 1.130"-1.135" for 115 gr FMJ/RN bullets.

Atlanta Arms match ammo which is used by various match teams, including Army Marksmanship Unit/Marine Service Pistol team, uses 1.130" OAL for 115 gr FMJ match ammo that has accuracy of 1.5" group at 50 yards loaded to minor power factor of 125/1150 fps (BTW, 1.145" OAL is used for 124 gr FMJ) - http://atlantaarms.com/products/9mm-115gr-fmj-match-amu.html

To increase consistency of chamber pressure and muzzle velocities, for my carbine load development with 115 gr FMJ/RN bullets, I tested 1.130" to 1.160" OAL with different powders/charges and so far, shorter 1.130" OAL with faster burn rate powders at near max/max charges are producing greater accuracy - http://www.thehighroad.org/showthread.php?p=10245856#post10245856

With that said, sometimes you have no choice but to load longer as loading shorter will compress the powder charge. For my accuracy testing with 124 gr Berry's/RMR bullets, 1.160" OAL was used with WST/Titegroup/BE-86 to not compress the powder charge to produce sub 2" groups at 25 yards - http://www.thehighroad.org/showpost.php?p=9924922&postcount=137

 

[LiveLife]

- PLATED BULLETS

Update to post # 182 with additional information - https://thefiringline.com/forums/showthread.php?p=4124597#post4124597

Plating thickness - Most jacketed bullets have copper alloy/gilding metal jacket thickness of around .015"-.030". Regular thickness plated bullets have around .004" thick copper plating and are usually limited to 1200 fps. Thicker plated bullets have .012"+ thick copper plating and are usually limited to 1500 fps. Below is a listing of copper thickness of various plated bullets as best as I could find:

Speer Gold Dot HP: .018"

Speer Total Metal Jacket (TMJ): .015"

Rocky Mountain Reloading Hardcore Match: .012"-.014" (rated to 1500 fps)

Berry's Thick Plated (TP): .012" (rated to 1500 fps)

PowerBond: .010"-.011" (rated to 1300 fps)

Berry's Regular: .0035"-.008" (rated to 1250 fps)

Hunting Shack Munitions: .005" (no fps rating)

Rainier Ballistics: .004" (rated to 1500 fps?)

X-Treme: Can't find any reference for plating thickness but rates the regular plated bullets to 1200 fps and "Heavy Plate Concave Base" plated bullets to 1500 fps

Frontier CMJ: Can't find plating thickness or fps rating

 

[LiveLife]

- 9MM POWDER SELECTION

Continuation of post #181 and #189 for powder selection and reloading tips.

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10325861#post10325861

Here's my grouping of powders suitable for 9mm by "relative" burn rate - http://www.thehighroad.org/showthread.php?p=10271016#post10271016

Faster burning pistol powders:

No. 2 - Bullseye - Clays - WST - Red Dot/Promo - 700X - TiteGroup - Solo 1000 - Am. Select - International - Trail Boss - PB - N320 - AS - Ba9 1/2, Ba10 - Prima V/SV - Clean Shot/D032-03

W231/HP-38 - Zip - Green Dot - SR7625 - N32C - 206V - A1 - S020

Slower burning pistol powders:

Unique - Universal - BE-86 - Power Pistol - N330 - Ba9 - Ultimate Pistol/D036-07

No. 5 - HS6 - WSF - AutoComp - CFE Pistol - Herco - Sillouette - 800X - True Blue - N340 - 3N37 - D-20 - A0 - Auto Pistol/D036-03

This post explains each powder with close up comparison pictures referencing W231/HP-38 - http://www.thehighroad.org/showthread.php?p=10094185#post10094185

I have Dillon 650 and powders you listed will meter well in the Dillon powder measure as they are small granule powders seen in the link above.

Just getting into reloading 9mm ... Mainly target loads but if i can get a nice defensive load too then great.

For lower velocity target loads, consider faster burning powders like Titegroup/W231/HP-38 from your list and slower burning powders for higher velocity defensive loads needed to properly expand JHP/plated HP bullets like Gold Dot.

W231/HP-38 has been my reference powder for 380Auto/38Spl/9mm/40S&W/45ACP/45Colt the past 25 years and do not consider it dirty. Unlike slower than Unique/Universal powders which must be loaded at higher charges to burn more efficiently and produce accuracy, W231/HP-38 is flexible and can produce consistent chamber pressures at lower charges for accurate lighter target loads. As Walkalong posted, Zip is comparable powder to W231/HP-38.

Titegroup burns hot and violent and can get spikey with pressure near max charges. With very narrow start/max charge range, small changes in powder charge, OAL/COL and bullet seating depth/setback can easily create over max pressure conditions and I do not recommend Titegroup to new reloaders. However, it is less temperature sensitive than W231/HP-38 and can produce more accurate loads so it is popular with match shooters needing to meet power factor requirement (2"-3" shot groups at 25 yards with Berry's regular plated RN/Titegroup) - http://www.thehighroad.org/showthread.php?p=9924922#post9924922

For decades, I have used WSF for defensive loads because of higher velocities/accuracy it produced compared to other powders. In recent years, have grown fond of BE-86 (which has similar burn rate as Power Pistol without the big muzzle flash) which I consider the modern Unique that meters well as BE-86 has produced more accurate 9mm/40S&W loads than my previous accurate loads (2" groups at 25 yards). - http://www.thehighroad.org/showthread.php?p=9924922#post9924922

I consider CFE Pistol comparable to AutoComp but unless you are loading near max, you will obtain greater accuracy with faster burning powders. BTW, many match shooters like faster burning N320 for accurate/clean lower velocity target loads and Walkalong likes slower N340 for higher velocity loads.

If you had to buy only one powder for mostly target shooting, I would suggest W231/HP-38. I would suggest Unique/Universal and slower powders for defensive loads but if you had to go with one powder for both target/defensive loads, BE-86 would be my recommendation as it has produced accuracy at lighter charges than other slower powders and capable of higher velocities. Here's THR mega thread on BE-86 - http://www.thehighroad.org/showthread.php?t=760289

rainer plated bullets

While I shot USPSA matches with jacketed bullets, I practiced with Berry's and Rainier plated bullets. What I found with regular plated bullets (around .004" thick plating) is they start to lose accuracy above mid range jacketed load data. With thicker plated bullets around .010"-.014" (Berry's TP, Power Bond, RMR HM, X-Treme HPCB), accuracy is maintained to max jacketed load data.

Many report less accuracy from 115 gr plated RN bullets compared to 124 gr plated RN bullets. I attribute this mainly to shorter bullet base which results reduced neck tension that leads to inconsistent chamber pressures. While most manufacturers size 9mm plated bullets to .355" diameter, Berry's size their 9mm bullets slightly larger around .3555" and RMR size 9mm 115 gr HM RN even larger at .356" to improve neck tension/chamber pressure consistency for greater accuracy. RMR goes one step further by using harder alloy core of 11-12 BHN (hence the name "Hardcore Match") which resists reduction of bullet diameter during bullet seating/taper crimp and I get less bullet setback (essentially none) compared to other plated bullets with softer core.

FYI, here's a listing of plated bullet thickness and velocity rating - http://www.thehighroad.org/showthread.php?p=10309500#post10309500

 

[blarby]

Just throwing my 2 coppers in:

I see retirement is treating you well, and there's a big hole in the mantle to fill.

Keep on keeping on....

 

[Jesse Heywood]

Another good powder is the discontinued IMR SR-7625. It is my favorite for lead, plated & jacketed in the 115-125 gr range. I haven't tried it behind 147 gr.

 

[LiveLife]

I see retirement is treating you well

Not quite retired yet.

Wife and I decided I will continue working until the mortgage is paid off which is about 1.5 years.

At least my job change will now keep me at home instead of driving out of town and allow me to do more reloading/shooting.

 

[LiveLife]

Continued from post #176 - http://www.thehighroad.org/showthread.php?p=10123314#post10123314

- CASE WALL FAILURE/RUPTURE - BULLET SETBACK/POWDER COMPRESSION

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10355950#post10355950

For me, concern with loading at max and beyond lies with reloading variables like quality/condition of brass, number of times brass was reloaded to undergo work hardening, whether the brass was shot in less supported chambers with hot loads (like 9 Major) to experience bulging/thinning/weakening of case wall and made to look like new with wet tumbling, etc.

Keep in mind that published load data were tested with NEW brass that handle chamber pressures better than used/mixed range brass we use (likely by new reloaders) that are often work hardened and brass will likely experience case wall failure/rupture instead of expanding/deforming to contain the pressure.

Walkalong's sentiment may come from too many "Funny thing happened at the range today" threads where case wall failure/rupture resulted from small KaBooms (without damage to pistol) to catastrophic failures (with permanent injury to body). Many of these incidents were experienced by seasoned reloaders who took care not to exceed published max charges but when root cause analysis/discussion took place, were determined that likely combination of reloading factors like work hardened, thinned/weakened brass and bullet setback compressing powder charge resulted in way over max pressures.

For this and many other reasons, I suggest to new reloaders with mixed range brass, to use powders that are less spikey at mid to high range for some pressure buffer until they are more familiar with the reloading process as stacking of reloading variables could raise pressures in a hurry, especially with small internal volume case like 9mm. If they want to work up near max/max load data, I suggest using verified once-fired brass or new brass.

 

[LiveLife]

- ENHANCING POWDER MEASURE DROPS

Regardless of powder measure I use (C-H/Dillon/Lee), after I pour powder into the hopper, I lightly tap the hopper around 10 times with my finger tips to settle powder before I start dropping charges to weigh for consistency.

 

[Hangingrock]

Powder measures, one not often seen but at one time in decades past were/was popular Belding & Mull with the stationary main powder hopper, secondary horizontal sliding reservoir depositing powder into an adjustable volume measure drop tube then charging the case. The horizontal sliding reservoir maintained a constant head of powder thus depositing a charge into the adjustable measure drop tube.

 

[LiveLife]

- 9MM CARBINE LOAD BULLET DROP/TRANSONIC EFFECT

Repost from another thread - http://www.thehighroad.org/showthread.php?p=10359018#post10359018

do you find it "worth it" to buy the lighter bullets and load specifically for the PCC (Pistol Caliber Carbine)? Is there enough of a difference in accuracy over the loads you usually shoot in your pistols?

I shoot steel challenge, uspsa and some idpa.

I think it depends on the distance to target.

Lighter 90-100 gr bullets traveling at 1450-1650 fps will drop less than 115/124 gr bullets traveling at 1250-1350 fps, especially out to 75-100 yards. With 115/124 gr loads at 100 yards, I have seen around 6" - 9" of vertical stringing while 100 gr loads around 5" of vertical stringing - http://www.thehighroad.org/showthread.php?p=10286159#post10286159

With 115 gr FMJ/HAP loads I am using as reference for Mythbusting plated bullet comparison thread, I got around 100 fps spread while 100 gr RMR Hardcore Match plated load with Promo produced down to 12 fps spread - http://www.thehighroad.org/showthread.php?p=10245856#post10245856

Another thing to consider when shooting at longer distance is the transonic effect on the bullet as bullet slows down from supersonic speed to subsonic speed around 1126 fps. At 100 yards, 9mm bullet will slow about 200 fps, so loads that chrono above 1350 fps should stay supersonic and produce smaller shot groups at longer distances, especially when factoring in reduced vertical stringing from bullet drop. If your load will likely go through transonic speeds before reaching the target, you can adjust the load to ensure it stays supersonic to target or subsonic at the muzzle.

For closer targets to 25 yards, I think the effects of bullet drop and transonic effect is small enough to not matter on the group size and for developing match loads, I would go with loads that are most accurate with your match pistol. If your targets are at longer distances, you may need to consider using a different load that will produce smallest group size.

 

[LiveLife]

- 9MM LOAD DEVELOPMENT FOR ACCURACY

Repost from another thread - https://www.thehighroad.org/index.php?threads/determining-your-accurate-reload.813866/#post-10413751

124g ... HP38 ... 3.9-4.4 ... Loaded 10 of each at 3.9, 4.1 and 4.3 grains of powder with an OAL that cycles well in my MP9.

... preference being for the load of 4.1grains of HP38 behind the 124g FMJ

Is there really some magical formula that I will see groups significantly tighten up? I guess I am curious your method of determining your magical load.

Here is my process for determining Max/Working OAL, powder work up to determine reliable slide cycling/case extraction/ejection and accuracy determination:


Determine Max/Working OAL and max case fill to avoid compressed loads:

- Use your barrel to determine the Max OAL
- Function test by feeding/chambering from the magazine to determine the Working OAL
- Subtract bullet length from Working OAL to determine the max case fill and weigh the powder charge to identify the max charge weight for the bullet/powder/OAL combo.
- Reference published load data to see if max case fill powder charge weight is below published max charge (If not, you may end up with a compressed max load and may need to use reduced powder charge or switch to a denser powder)


Powder work up to identify lighter target load and accuracy nodes (This process is for semi-auto pistol which must cycle the slide):

- If your Working OAL is longer than published OAL, use the published start charge
- If your Working OAL is shorter than published, consider reducing your start charge by .2-.3 gr
- Check neck tension by measuring OAL before/after chambering/feeding from the magazine. If bullet setback of more than a few thousandths becomes a persistent problem, you may need to use shorter OAL or larger diameter bullets (If using .355" sized plated bullets, Berrys sells slightly larger sized .3555" bullets and RMR/X-Treme sells .356"/.357" sized 9mm bullets)
- Load 5 rounds of .2-.3 gr incremental charges from start to mid range to first identify the powder charge that will reliably extract/eject spent cases and cycle the slide (This could be your target load)
- Load 10 rounds of .1-.2 gr incremental charges above the load that reliably cycled the slide to max charge
- Using copy paper targets at 7 yards and bingo dauber dots, place dots for each incremental charge (Depending on your shooting level, use 1 dot per paper or 2/4 dots per paper). This process is similar to OCW for rifle.
- Shoot 3-5 round groups of each increment charge and look for accuracy nodes/trends
- Repeat at 15 yards to verify accuracy nodes/trends


Fine tune accurate loads:

- Slug your barrel to determine groove-to-groove diameter. If groove diameter of barrel is .356"+ and using .355" sized plated bullets, consider using larger sized bullets from Berry's (.3555") and RMR/X-Treme (.356"/.357")
- Fine tune your accurate loads further by shortening OAL to increase neck tension for more consistent pressure build and to reduce/eliminate bullet setback (Match loads used by AMU is 115 gr FMJ loaded to 1.130")
- Try using least amount of taper crimp to reduce case neck/mouth to chamber seal time and to eliminate reducing bullet diameter (Since case wall thickness average .011", I usually add .022" to the diameter of bullet for taper crimp amount. So for .355" sized bullet, .377" taper crimp)

 

[LiveLife]

- OAL/COL DETERMINATION FOR MBC 9MM 124 GR RN (SMALLBALL)

Repost from another thread - https://www.thehighroad.org/index.php?threads/mbc-plunk-test-failure.820973/page-2#post-10542545

MBC 9mm 124gr "small ball" with Hi-tek ... OAL of 1.15. When I do this the plunk test fails and sticks in the barrel (Glock 43 and a Sig P320 compact)

... I'm guessing this is due to the shape of the MBC ... tested in my Sig at 1.10 and worked just fine. Pulled the Glock out of the safe and it did not pass. Now it's time to set at 1.08 and test again

Yes, MBC 9mm 124 gr RN "SmallBall" loaded to 1.150" OAL sticking in the barrel is due to the nose profile (ogive) of the bullet. If you look at the comparison illustration below, instead of more typical longer pointed nose, SmallBall has shorter rounder nose that increases the bullet base/bearing surface length that engages the rifling.

Comparison picture below shows MBC 124 gr RN (SmallBall) with longer bullet base/bearing surface than more typical Dardas/ZCast RN (stepped) that have shorter bullet base. Benefits of longer bullet base are deeper seated bullet base which increases neck tension and more consistent chamber pressures (compare bullet bases of SWC/CN bullets to bullet bases of two stepped RN bullets).

As you found out, MBC SmallBall needs to be loaded shorter to clear the start of rifling in most barrels and I use 1.080" OAL for my barrels.