AR-15 Pistol Build...Maybe.

[Jack19]

I'm fairly seriously considering building an AR pistol in either 556 or, maybe, 300BO.

Have any of you done this? Would like to hear your impressions re barrel length vs accuracy, and at what distance, sights, braces, gas vs. piston, etc.

Haven't built and AR in about 15 years, so this will be a re-learning experience.

Any and all advice appreciated.

 

[Lightcs1776]

Wish I could help, but I have no experience with this topic. I'm interested in learning though.

Sent from my XT1254 using Tapatalk

 

[jkingrph]

It's been six or seven years since I built any, and all I can think of is to make sure you have the correct tools and an upper action block to clamp the upper receiver in when torqueing the barrel nut. Whatever caliber you choose, use a good barrel, and trigger, every thing else is kind of redundant. All I built was a 5.56 and a few in 6.5 Grendel. Good luck!

 

[Ad Astra]

Go with the Blackout! It's a happening cartridge ... anything from a 200+ gr. thumper to a zipper. And ammo's cheap online.

Get a threaded barrel in case that hearing protection act passes. Hearing's important.


AA

 

[xjrob85]

I've never built an AR pistol, so I'm no expert, but I've heard that if you ever want to run a suppressor, you want a minimum 10" barrel length. I've also never seen a piston AR pistol. They might exist, but I've only ever seen direct gas impingement guns with a pistol length gas tube.

 

[dreadpirate]

I have built one. This is an 1 in 7 twist upper in 5.56 from Palmetto State Armory with a 10.5 " barrel, and KAK pistol brace and buffer tube, a Magpul grip, a Vortex SPARC AR red dot, a Magpul angled fore grip (can't use a horizontal grip), and an ALG ACT trigger. The backup iron sights are from Palmetto State Armory as is the lower parts kit. It uses a standard weight buffer and functions perfectly.

It seems to shoot very well - have not tried out to 100 yards with it; when sighting in at 25 yards the shots were on top of each other. What else would you like to know? It's a lot of fun to shoot!

 

[dreadpirate]

I've never built an AR pistol, so I'm no expert, but I've heard that if you ever want to run a suppressor, you want a minimum 10" barrel length. I've also never seen a piston AR pistol. They might exist, but I've only ever seen direct gas impingement guns with a pistol length gas tube.

I would add that if you want to suppress the rifle, then install an adjustable gas block. I too would not get anything shorter than 10.5" for 5.56; the velocity would be too low in my opinion. For 300 blackout you could get away with a shorter barrel - but again - I really recommend you install an adjustable gas block as the suppressor will change the dynamics of the weapon and it may need to be adjusted. The adjustable gas block makes this super easy.

 

[dreadpirate]

If you want to go "top shelf", then have a look at this AR pistol from Windham Weaponry (I have a Windham Weaponry upper and it's awesome).

https://www.windhamweaponry.com/firearms/pistols/223-556-caliber-pistol-2/rp11sfs-7/

And here is a really nice upper from BCM. I have an AR with a BCM upper and it's a tack driver:
BCM BFH 11.5'' Carbine Upper Receiver Group w/ BCM KMR-*ALPHA* 10'' Handguard (NFA)

If you end up converting it to an SBR - then the 11.5" barrel length is a good choice for 5.56. That's my only minor regret; not going 11.5". If the BCM and Windham offerings seem pricey, honestly, I think PSA makes quality uppers that are good enough for a pistol/SBR build. 10.5" is sufficient. This is not a match rifle!

PSA 10.5" 5.56 Nitride 9" M-Lok Freedom Upper - Without BCG or CH -516446319

 

[dreadpirate]

Here's another great alternative; build your own upper. I would say get a quality upper (Spikes for example) and a barrel from Odin Works. These come with adjustable gas blocks.

233 Wylde 10.5'' Carbine ULTRAlite
300 Blackout 10.5'' Barrel

You'll need a gas tube - but those are like $12.

I would say also get a Midwest Industries G3 M-Series One Piece Free Float Handguard, M-LOK. These are easy to install, you don't have to "time" the barrel nut.

If you want to build your own upper, keep in mind you will need some specialized tools to hold the upper in a vice, a torque wrench and claw, roll pin punch set, and armorers block. And if you go to all that expense - you might as well build several uppers

 

[OkieStubble]

Great posts @dreadpirate, very informative. That's a nice looking PSA, but all of your guns I have seen are nice looking. +1 on PSA, can't get better for the prices that they offer. I keep a department issued SBR in my car which is a 11.5 LWRC but it's piston.

I Have actually just recently been researching MI's free floats for my Colt. Do you prefer M-LOK over KeyMod?

 

[dreadpirate]

Great posts @dreadpirate, very informative. That's a nice looking PSA, but all of your guns I have seen are nice looking. +1 on PSA, can't get better for the prices that they offer. I keep a department issued SBR in my car which is a 11.5 LWRC but it's piston.

I Have actually just recently been researching MI's free floats for my Colt. Do you prefer M-LOK over KeyMod?

Thanks! I like M LOK. You can attach plastic components (Magpul accessories); don't think key mod supports that.

 

[xjrob85]

Do you prefer M-LOK over KeyMod?

M-LOK is the way to go. KeyMod seems to be losing popularity due to the slots being damaged and the attachments falling off if dropped. Recently a study was performed comparing the two platforms and they found that M-LOK rails are significantly stronger, attachments remain in place when dropped, and attachments can be removed and replaced with minimal point of aim shift. By comparison, KeyMod performed very poorly.

Here is a link to the study if you are interested:
https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2017/armament/McGee19427.pdf

 

[nortac]

M-LOK is the way to go. KeyMod seems to be losing popularity due to the slots being damaged and the attachments falling off if dropped. Recently a study was performed comparing the two platforms and they found that M-LOK rails are significantly stronger, attachments remain in place when dropped, and attachments can be removed and replaced with minimal point of aim shift. By comparison, KeyMod performed very poorly.

Here is a link to the study if you are interested:
https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2017/armament/McGee19427.pdf

Pretty definative results right there!

 

[OkieStubble]

Pretty definative results right there!

+1 Thanks for the great link Rob!

 

[Claudel Xerxes]

I have built one. This is an 1 in 7 twist upper in 5.56 from Palmetto State Armory with a 10.5 " barrel, and KAK pistol brace and buffer tube, a Magpul grip, a Vortex SPARC AR red dot, a Magpul angled fore grip (can't use a horizontal grip), and an ALG ACT trigger. The backup iron sights are from Palmetto State Armory as is the lower parts kit. It uses a standard weight buffer and functions perfectly.

View attachment 811011

It seems to shoot very well - have not tried out to 100 yards with it; when sighting in at 25 yards the shots were on top of each other. What else would you like to know? It's a lot of fun to shoot!

I know that this is an old thread, but I was wondering if you still have and shoot the pistol. I've been toying with the idea of getting a PSA pistol, opposed to something in the $1000+ range.

 

[OkieStubble]

I know that this is an old thread, but I was wondering if you still have and shoot the pistol. I've been toying with the idea of getting a PSA pistol, opposed to something in the $1000+ range.

I think an AR pistol is the perfect foundation to do a first build. I wonder what and how much the price differences are between PSA components and Aero Precision components?

 

[Claudel Xerxes]

I think an AR pistol is the perfect foundation to do a first build. I wonder what and how much the price differences are between PSA components and Aero Precision components?

Just by glancing on their website, Aero seems to be more expensive than PSA. If I get near the $1000 mark, then I have a couple of complete pistols that I'd consider getting instead of building one.

 

[nortac]

In my case, building an AR pistol or rifle, will let me choose an assortment of premium features that I want, as opposed to a predetermined package from a company looking to sell at a given price point.

 

[OkieStubble]

If I'm going to build a bargain priced AR pistol, can't I just simply purchase a complete AR pistol which is already bargain priced without building?

 

[nortac]

If I'm going to build a bargain priced AR pistol, can't I just simply purchase a complete AR pistol which is already bargain priced without building?

Of course you can and most probably do. If a stock off the shelf item meets all of your requirements, there is no reason to undergo building an equivalent item, even if you save money, is it worth the hassle? In my particular case,
1) I want the experience of building an AR.
2) I get to choose the features and components in a combination that may not be available in a stock item.