Possible AR pistol build

kc7pwx

Gunny Sergeant
Full Member
Minuteman
Apr 24, 2020
528
686
Washington
I have an extra AR-15 lower that I do not have an upper for and I am thinking of building an AR pistol
I have ruled out a 9 mm as I all ready have a Calico Liberty 3.
I also ruled out the 556 because as I understand it 556 looses it effectiveness in under 7.5" barrels and if I do this I want it to be very short.
I am looking at doing a 45 with no longer than a 5" barrel, possibly shorter, and I all ready have 2 suppressors for 45.
Stern Defense makes a magazine adapter for the AR-15 that allows you to use the 45 ACP M&P magazines.
Unfortunately the largest magazine that I can find for that gun is 14 rounds and I do not know if I want to undertake this build for only a 14 round AR pistol.
Does anyone know of a larger magazine that will work in a 45 ACP M&P handgun?
Does anyone know of a company that can custom make a stick or a drum magazine that would work in a 45 ACP M&P?
 
Why not do a 300BO with an 8” barrel? If you run subs, you’ll have roughly the same energy as a 45 ACP (IIRC), and better external ballistics assuming you use a 208/215/220 SMKish bullet profile. Plus, you could always switch and run supers if you needed more lethality.
 
14 round of .45 is hardly a lack of fire power...honestly its hard to imagine a scenario where 14 rounds would leave you under gunned.

regarding custom mags....for someone to custom make you a mag, it would likely cost more than your entire build, for 1 magazine.....thats not a cheap endeavor
 
I have a AR45 with a 7" Barrel and dedicated can... Its a blow back gun, 230gr are rough... I load 185gr ammo and it runs pretty good. I use SGM Tactical Glock 26round magazines so I cant help you on the magazine part. I dont run a mag adapter, I run Billet 45ACP/10MM Glock lower and uppers.



I have 2 of these guns. 1 in 9mm with a 7" Wilson 9mm SS match barrel and the second in 45ACP with a 7" Wilson 45ACP SS Match barrel.


Here the AR9 with Glock 33rd mags, but the 45 looks exactly the same...




 
I thought I read endomag was looking into an insert similar to their’s for 9mm.

They should if not.

A shorty .45 AR with a can would be a hoot.

Or just get a Hi-Point Carbine!!😎
 
I snapped a few pics of my AR45 pistol for you. The first pic is with a OEM Glock 45acp 14rd mag and the KRISS .45 Mag extender giving me 30rds. This runs like a dream with zero issues... The second pic is with the SGM 26rd 45ACP glock mag....it works most of the time, but does have some issues every once in a while.

My 185gr handloads are stupid quite and hit steel like a sledge..

Spartan 45/10mm Billet Glock Lower
Spartan 9/45 Billet Upper with LRBHO
7" Wilson 45ACP SS Match Barrel Threaded .578-28
Seekins MCSRV2 9" Handguard
ERGO Grip
Ambi Safety
ALG ACT Trigger
Quarter Circle 10 45ACP BCG
BCM Large Latch CH
SB Tactical Pistol Brace
KVP 10oz Buffer
Rugged Obsidian 45 K Config



 
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That is a nice looking pistol.
I have 3 of the Kriss 30 round mags. I got them for my Glock 21 Mechtech conversion.
The only problem is that would require buying another lower and I am looking to build up the lower I have before buying another lower.

I have sent a message to the Endomag people to inquire about a 45 acp conversion and hopefully they will say they are planning on building one.