Pistol Caliber Carbine Builds - Parts sales and What parts did you use and why?

Status
Not open for further replies.
I ordered a PSA pistol lower a week ago. Now I just have to wait until uppers are back in stock.

This is a great thread! (Mods any interest in substituting this one for the AK mag hold open sticky??)
 
Hey where'd the guy who started this thread, disappeared faster than the Enterprise in warp :)

So curiosity, all weapons not being created equal, anyone have an opinion on what weight 9mm bullet has shown to work better than others? Have 115 FMJ and some 124 FP but was wondering if I should order a small pack of 147's to load also. Still working on getting parts together. Thanks.
Sorry, got activated for Federation Reserves duty and been busy fighting off the Borg ... dang near got assimilated too. :eek::D


I have tested 100, 115, and 124 gr FMJ, JHP and thick plated bullets (rated to 1500 fps) with Red Dot/Promo, IMR Red, Vectan Ba 9.5, IMR Target, Sport Pistol, W231/HP-38, BE-86 with different OAL/COL from low SAAMI minimum (1.110") to almost maximum (1.160") using 17" Just Right Carbine, 16" PSA M-Lok/KeyMod/MOE uppers with M&P15/Spike's Tactical/Anderson lowers/PSA metal block/Joe Bob Outfitter/Frontier Armory dedicated lowers on these threads:

https://www.thehighroad.org/index.p...n-9mm-40s-w-45acp.799231/page-4#post-10338994

https://www.thehighroad.org/index.php?threads/700x-one-pound-later.825599/#post-10629316

https://www.thehighroad.org/index.p...-and-vectan-ba-9-5-ba-9.817796/#post-10508215

https://www.thehighroad.org/index.p...ectan-ba-9-5-ba-9.817796/page-2#post-10519646

https://www.thehighroad.org/index.p...ectan-ba-9-5-ba-9.817796/page-2#post-10520702

https://www.thehighroad.org/index.p...ectan-ba-9-5-ba-9.817796/page-2#post-10523519


Based on my limited testing, here's what I found:
  • Lighter weight 100 gr bullet pushed to 1500 fps produce less vertical stringing from velocity drop at 50-100 yards
  • Blowback carbines seem to produce accuracy trends at different powder charge levels (mid range load data vs near max) often with small powder charge difference of .2 - .3 gr
  • Jacketed bullets did not always produce greater accuracy compared to RMR thick plated bullets (This was a surprise to me)
  • Sizing of bullet diameter seems to affect accuracy (.355"-.3555" sized jacketed bullets compared to .3565" sized plated bullets)
My current low cost plinking round is RMR 115 gr FMJ with 4.1-4.2 of Promo loaded short to 1.110"-1.115" (OAL variance I get from my progressive press) for greater neck tension/more consistent chamber pressures - light target load pleasant to shoot in M&P Shield 9mm (4.4-4.5 gr Promo is closer to Winchester White Box). These loads produced around 1" 10 shot gropus at 25 yards good for minute of soda cans which these are intended for.

index.php


Below are examples of accuracy trend I found common during powder work up (yes, I am using mixed range brass) with different powders where small changes of .2-.3 gr would produce significant change in group size but made identifying accuracy nodes easier (near max loads didn't always produce the smallest groups) -

index.php


index.php


Load with lowest ES/SD numbers was with RMR 100 gr thick plated RN with 4.5-4.7 gr Promo loaded to 1.050" (essentially 100% case fill load) produced 13 to 16 fps spread depending on temperature. Here are chrono data:

100 gr RMR HM RN 4.5-4.7 gr Promo @ 1.050": 1478-1475-1480-1471-1467 fps (58 F - JR carbine)
100 gr RMR HM RN 4.5-4.7 gr Promo @ 1.050": 1458-1450-1445-1442-1448 fps (71 F - JR carbine)

This load produced mostly sub 2" 10 shot cluster group at 50 yards, producing slightly smaller group than reference 5.5 gr W231/HP-38 load - https://www.thehighroad.org/index.p...n-9mm-40s-w-45acp.799231/page-3#post-10245856

index.php


And 3" 100 yard 10 shot group, I mean pattern. :D

index.php
 

Attachments

  • RMR115FMJPromo25yard.jpg
    RMR115FMJPromo25yard.jpg
    50.4 KB · Views: 2,683
  • 25YardIMRTargetRMR115FMJ.jpg
    25YardIMRTargetRMR115FMJ.jpg
    34.1 KB · Views: 1,533
  • 25YardSP4.jpg
    25YardSP4.jpg
    38.8 KB · Views: 1,131
Last edited:
Here's the latest product for my PCC journey - TorkMag G-Block Glock Magwell Adapter for AR-15 lower. Instead of using Colt pattern magazines for AR based carbines using mag block, now I can use Glock magazines in regular AR lowers.

 
Thanks for the bullet info BDS! I was looking at the Tork mag also, but ended up getting that glock dedicated lower. Already starting to order parts, just ran into issue with trying to find a vice block for it, because most are made for standard AR lower.
 
What about the Stern Defense Mag-AD9 AR-15 Glock mag adapter?

https://getstern.com/products/mag-ad9

It has its own mag release, but I think I'd prefer that to having to carve up all my Glock mags. Has anyone tried one of these? It has been getting good reviews thus far, and it seems like a prime candidate for use in an SBR'd AR-15 lower.
 
Last edited:
I've recently built several carbines (45ACP and 10mm) using the New Frontier Armory upper and lower. I very much like the fact that in most every way they are standard pattern uppers and lowers, plus I appreciate the last round bolt hold open feature.
 
Got tired of waiting for Palmetto to get the lpk kit I wanted in, went to a couple of different places and got everything ordered for around the same price they were offering. I cannot wait to get this thing started, to say I got the building bug is an understatement...
 
I’m glad I found this thread. I recently purchased a PSA billet Glock lower, along with a PSA 16” AR-9 upper. This is my first AR-9, and I’m still waiting for the upper to ship, but in the meanwhile I’ve been reading up on buffers and springs. I purchased a Spikes Tactical 8oz. buffer after reading a lot of suggestions that heavier buffers are better for these blowback rfiles, and I also have a spare Wolff XP spring laying around. I figured with the 5.5 oz. bufffer and car spring that came with the rifle, the 8oz. bufffer, and XP spring, I’m bound to find a combo that works.

I’ll report back once I get it figured out.
 
Went with the KAK 9mm buffer, 5.4oz, standard carbine spring. WIll see how this one goes. If its smooth great, if not maybe I'll throw some quarters at the bottom of the stock or get a heavier buffer.
 
Got to test my new PSA AR-9 today (see a few posts above for details). With a Spikes 8oz. buffer and car spring, it ran 100% with 115gr, 124gr, and 147gr. The ejection was noticeably weaker with the 147gr, but it was freedom munitions which is known to be underpowered. With the 115 and 124gr ammo, the recoil felt similar to a 5.56 AR, although the “sproing” was more pronounced. The only thing I may change is the trigger, but I’m very happy with it overall, and loooking forward to PCC competition this year.

ETA: the PSA bolt weighs 14.9oz, so the total bolt + buffer weight = 22.9oz.
 
Last edited:
Got to test my new PSA AR-9 today (see a few posts above for details). With a Spikes 8oz. buffer and car spring, it ran 100% with 115gr, 124gr, and 147gr. The ejection was noticeably weaker with the 147gr, but it was freedom munitions which is known to be underpowered. With the 115 and 124gr ammo, the recoil felt similar to a 5.56 AR, although the “sproing” was more pronounced. The only thing I may change is the trigger, but I’m very happy with it overall, and loooking forward to PCC competition this year.
Were the rounds all round nose?? I tried a plunk test on a flat point and did not seem to like those..
 
If I had to do it over again I might have used a pistol lower. There are certainly a LOT more options in barrel lengths when using a pistol lower and stabilizer/brace.

My PSA Lower for Colt mags won't feed truncated cone lead bullets at all. FMJ is just fine.
 
FINALLY!!! Got the new build out to the range. Worked perfectly, recoil not bad, might play with heavier buffer or maybe just a spacer but thats it. Sighted it in a 25 yrds, extent of the indoor range. Then weird thing, got great groupings with 115 gr FMJ. Switched over to some 115 plated RN and the grouping went to the right. Both rounds were set to 1.100 oal, the FMJ's were CFE-P and the plated were HS-6, mixed brass on both. Any thoughts?
IMG_1807.jpg
 
I have fired some of the Federal Champion plated ammo and I don’t care for it.
You have to remember that all ammo is not the same. Point of aim and impact will very sometimes.
You will also find that some guns are finicky about what you feed them and some will eat anything.
If you’re looking for cheap plinking ammo, buy a few boxes of different brands and see which shoots best. Then order bulk. Most 115gr 9mm FMJ can be found for 19 cents a round when buying by the thousand.
 
Gunny, I tried some dummy 124 plated FP bullets and they couldn't pass the plunk test until the OAL was so short there would be no way I would load em. I was just surprised that there would be such a difference between the plated and FMJ. Probably will try some 124 FMJ next since I know the 115's work spot on. Was just happy that the rife performed as expected.
 
Have been considering a Quarter 10Circle SBR build in 10MM so I could build a 200gr subsonic load and add a suppressor for some fun but can’t seem to justify the cost since I already have a .300 Blackout suppressed SBR. They just came out with their 10 MM barrel in 10.5” and it’s costly
 
Status
Not open for further replies.
Back
Top