Horrible 9mm results: 124 LRN, 5.2 Unique, FCD

[Steve Koski]

A friend claimed to be getting shotgun patterns from this ammo (Glock 17, same results with stock barrel and Lone Wolf barrel). I didn't believe him 'till I fired some tonight.

From a rest at 15 yards I was getting 9-10" groups with the 124 LRN/5.2 Unique combo. COL was a hair short at 1.090. With some Fed 115 gr factory ammo the LWD barrel was shooting 3.5" groups, the stock barrel 2.5" groups.

The pulled bullets are being sized (probably by the Lee FCD) from .356" down to .355"-.354". This may be the problem/part of the problem.

Maybe it is also that the load is too hot. A friend of mine gets good accuracy from this same combo at 4.2 gr Unique.

The short COL may be part of it, but I can't imagine that shrinking the COL a bit could be that detrimental to accuracy.

What other factors could be in play? Your thoughts?

Thanks,

Koski

 

[Steve C]

Kind of what happens when you just "pick" a load rather than working one up. Data for 125 gr lead RN varies from 4.1gr of Unique to 6.0grs depending upon bullet manufacture and hardness. 5.2grs is over Speers data for their soft swagged bullet and under a calculated 5.4gr -10% start load for Alliants older data of 6.0grs maximum though this load would be hot if compared to more recent data. Without having an idea of bullet hardness its hard to determine if your load is too hot or not hot enough.

Assuming the bullets are decent. with consistent weight and do not have any internal voids or other casting mistakes then you need to explore some lighter and heavier loads. Load up 6 batches of 8 rounds each loaded at 4.3, 4.5, 4.7, 5.4, 5.6, 5.8. grains. Shoot them for group starting with the lowest charge and see if you can find a load that shoots well. Stop if pressure signs appear.

 

[ArchAngelCD]

The pulled bullets are being sized (probably by the Lee FCD) from .356" down to .355"-.354". This may be the problem/part of the problem.

Steve,
It's highly unusual for a Lee FCD to resize a bullet. The post-sizing only happens when something is really out of spec. I have been loading 9mm ammo with both jacketed and lead bullet for years now using a Lee FCD and it has never resized the bullet.

Like said above, you really have to work on loads for accuracy in your pistol. Even if I gave you a load that's accurate in my gun in might not be accurate in your gun.

 

[Steve Koski]

Thanks for the comments.

Agreed: The load should have been worked up and tested for accuracy. But my experience tells me that if the bullet agrees with the gun, then the difference between any given load and any other load is minimal. There may be a "sweet spot" but it doesn't vary the group size by 400%.

Hell, maybe it does in this case. Maybe this bullet just can't be driven that fast in this gun, with either barrel. Seems weird though. I can normally drive cast bullets as hard as I like and not have problems.

Oh - and I think you'll find that the FCD quite frequently sizes cast bullets down. How else are they shrinking? It may not matter in some/many cases, but this is a well documented issue with the FCD.

The bullets are from a local commercial caster. They're pretty good quality.

Thanks again,

Koski

 

[ArchAngelCD]

How else are they shrinking?

It's possible you have a defective die. It's rare but not unheard of.

 

[Steve Koski]

Then all FCD's are defective. Get your mic out. and measure some cast bullets pre and post FCD. Measure down low, far from the case mouth area. It'll be smaller. I should know better by now that to have that thing in my toolhead.

Oh, and this was all with R-P brass, if that matters. Could be thicker...

At least one problem is in play - basic stupidity for not working up a load and testing for accuracy.

Koski

 

[ArchAngelCD]

Forget I said anything, alright.

 

[GooseGestapo]

The Lee factory crimp die is adjustable. Obviously, the die has been set for crimping jacketed bullets at .355" and an excessive amount of crimp is being applied to the cast bullet, if it's reducing the diameter. Also, the die may need to be backed off some, too. I'd suggest that the die body be backed off about 1/4 to 1/3 turn.

It's not just the die. I use a Lee factory crimp die in loading my 9mm ammo. I use it for the purpose of improving the concentricity of the tapered 9mm ammo, and in my case, it works. My cast bullets fired from my S&W PPC-9 "Limited" w/6"bbl will group inside 2" at 50yds. Often, I find that depending on the mould, it helps to size the 9mm bullets to .357" or even .358" if they will chamber in the particular gun. I do however, reset the crimp when loading jacket bullet ammo, though that isn't very often....given the cost of "factory" produced bullets these days. (I cast all of my own...)

The second reason you are seeing poor accuracy is that the Glock barrels aren't well suited for cast bullets. They are in effect made "worn out" with the polygonal rifling. I've only gotten decent accuracy with Glocks with cast bullets at minimal velocities with very hard alloys, and cast "over sized". My "accuracy" load for my M22 (.40S&W) is a 180gr TC at ~875fps over 4.0gr of Bullseye. That, and they are sized at .402", also.

Reducing the powder charge to ~4.8gr (5.2gr is a rather "warm" load, in my experience) and backing off on the crimp adjustment should do the trick for improving the accuracy, if it can be fixed. My "factory crimp" die is an older one, and it only sizes the base of the case, not the short "neck" area of the loaded round. Not sure about those made/sold in the last 5-7years......

The rifle and pistol "factory crimp" dies are two entirely different animals, as are the straight wall cases vs. the 9mm "tapered" case die. The straight case "factory crimp" dies are a sure fire disaster for accuracy with cast bullets.

I also noticed that you are using Remington cases. I've not had happy results with the Remington 9mm cases. They seem to be "small" in the case head area and don't give me good consistency and concentricity. Hence, I avoid them..... I use Federal Nk cases from HydroShok factory ammo for my cast bullet loads, and Starline "brass" cases for my jacketed bullet ammo, fwiw..... Winchester for that ammo that I'm "giving away"........ Remington gets left on the ground....

 

[ironhead7544]

I never had a luck accuracy wise with lead bullets in the 9mm. Then I tried the 160 gr bullet meant for the 38 Super. Needs very light loads but will work in a Glock 17 barrel. Need to use the Lee FCD as the case may bulge a little at the bottom due to bullet length. I loaded them light as possible with 100% function in the G17. Has worked well in any number of 9mm guns including carbines and SMGs. Do a search for more info.

 

[LiveLife]

FYI, both Glock and Lone Wolf barrels have .355" groove diameter and .356" diameter lead bullets that are .001" over should work fine.

I shoot Missouri Bullet 18 BHN 9mm 125 gr LRN (SmallBall) loaded to 1.100"-1.120" OAL (depending on the pistol) out of my Lone Wolf barrels with W231/HP-38/Promo with good results. (I used Alliant 2004 load data provided by Steve C for Promo testing).

BTW, 2004 Alliant load data shows 5.5 gr as max (1139 fps - 31700 PSI out of 4" barrel) for Unique with 125 lead bullet at 1.15" OAL (load data just shows "L" so not sure what the bullet nose profile used was). There is no published lead load data for Unique and 9mm in the 2011 Alliant load data so the usual THR disclaimer/warning applies here if you are using the new "reformulated cleaner burning" Unique and older 2004 load data.


Steve K, I would recommend your friend remove the FCD and reload with just 3 dies to see if things improve with the following:

- For .356" diameter lead bullet, taper crimp should be .020" over = .376"
- Determine the max OAL by dropping a dummy round (no powder/primer) in the Lone Wolf chamber that will freely drop and spin without touching the rifling
- Determine the ideal OAL by feeding/chambering from the magazine and manually releasing the slide
- Load 10 rounds of each powder charge beginning at the start charge and work up towards max in .1-.2 gr powder increments

Your friend should be able to identify the OAL/powder charge that produces the most accurate shot groups with minimal/no leading. Once that OAL/powder charge is determined, put the FCD back in and reload to the same OAL/powder charge. If the accuracy/leading suffers, then tell your friend to leave the FCD in the die box and reload without it (What I tell all the new reloaders I help setup).


You may not be able to shoot the same load in the factory Glock barrel with same results as LW barrel because the Glock barrel has longer leade (space the bullet "jumps" from the case neck to the start of the rifling) and more hot high pressure gas will leak around the bullet and blow the liquefied lube from the surface of the bullet and out the barrel leaving the bullet "naked" without lube to seal the bullet to the barrel resulting in gas cutting/bullet base erosion and fouling/lead smearing at the chamber end of the barrel. Also, Glock rifling is much smoother "rounded" hill/valley than traditional "sharp square" land/groove and the barrel has polished finish/coating, which all results in the lead bullet less able to grip the rifling and "skid/slide" down the barrel rather than rotate with the rifling if pushed too hard (ask me how I know ) so a separate load workup is warranted if poor accuracy/leading results.

Have your friend test fire the load determined from above steps and see what the results are. If the accuracy/leading suffers, he will need to repeat the same steps for the Glock barrel and end up with two different OAL/powder charge loads for each barrel.

Also, as rcmodel and I normally recommend when shooting lead loads in Glock barrels, even with the ideal OAL/powder charge loads due to the reasons mentioned above, more gas cutting and fouling/lead smearing tends to buildup at the chamber end of the barrel to warrant inspection after 200-300 rounds or so and cleaning of this buildup as necessary. I take a mini cleaning kit to the range with me if I plan on shooting a lot of lead rounds out of my Glock barrels (Lone Wolf barrels will usually stay clean for the duration of the typical range session).

I hope this helped.

 

[ColtPythonElite]

I have loaded a good sized pile of 124 gr LRN over 5.0 gr. of Unique. I shot them out of a S&W 5906. That combo shot as good as the Federal Hydroshocks that I carried and qualified with back when the gun was my duty weapon.

 

[Sapper771]

I would ditch the FCD. After that, i would make about five or so dummy rounds (no powder or primer), pull the bullets, and measure their diameter. It is quite possible that the cartridge case is swaging your bullets down in diameter. I have seen a 9mm case swage a 0.358" bullet down to a 0.355".

Good luck.

 

[Steve Koski]

I ditched the FCD and loaded up 20 more rounds with 4.2 Unique and a 1.130" COL. I adjusted the crimp to give .380" diameter at the mouth. It looks wide, but the manual shows. But I gave the ammo and the gun back to the G17 owner, and won't be able to test 'em myself.

Yeah, I changed a lot, and if they work we can't say, "X was the problem." I'll let you know what he reports.

GG,

I had the same rotten accuracy with the LWD barrel too.

Sapper,

I'm gonna try your test to see if the case is swaging the bullets, or if it's the FCD. Easy to test right?

bds, CPE, & Ironhead,

Thanks for the info. Take care.

Koski

 

[Steve Koski]

Sapper & AACD:

I just did the test. Here are the results.

The act of seating the bullet is reducing the diameter by 1/2 to 1 thousandth (near as I can measure).

Seating a bullet then running it into the FCD results in a total reduction of 1 to 3 thousandths. Most measurements were at 2 thousandths smaller.

So it looks like just seating the bullet costs roughtly .001" and if you then run it into the FCD it cost you roughly another .001".

Koski

 

[918v]

Haven't you read any of my prior FCD rants?

I would recommend your "friend" try some 125gr TC bullets meant for the 38/357 sized .357" - .359" seated to 1.050" or so. They shot .75" groups from my M9 at 15 yards when propelled by 3.7 - 4.1 grs of 231.

I understand the Glock has different rifling, but I'm sure it will do better than 3".

 

[chris in va]

Need to get a 358 bullet, not a 356.

I had horrible 'patterns' with 356 until a wise person pointed me to the Lee 358-125-RF mold. It drops at .362 so I size it back down to 358.

 

[rg1]

I'd also try seating to a longer overall length. 1.090 is very short for a round nosed bullet. Maybe too much of the lead bullet is inside the case for you FCD die. I load 124 jacketed round nose to 1.150" for my 9MM pistols and carbine rifle. Do a check to make sure they will chamber in your barrel and I would agree that 5.2 is getting warm with your lead bullets.

 

[Steve Koski]

918v - I've read a lot of your "writings." Did you learn from Ted Kazcynski or Al Gore?

 

[918v]

Charles Manson.