9MM AR question

A magwell adapter is required to convert any mil spec AR15 lower to accept 9mm Colt mags.

You will also need a 9mm buffer.

There can be compatibility issues between the trigger group and upper (configuration dependent) so be aware. I needed to add a FA hammer to cycle properly.

Hope this helps.

The 9mm collection ....

1-IMG_0242_zpszmee6gpx.jpg
 
You can get adapters. That insert like mag then get secured by a Allen bolt. Any lower works as long as it got a 9mm buffer and either a M16 hammer or 9mm Hammer. No AR15 hammers with a notch on top.
 
Colt secures the adapter by drilling into the lower and using roll pins to secure it. Why don't you just import a 9mm lower.
 
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Lots of companies make mag block adapter ( Pro Mag, Spikes, RRA , CMMG ) . The best of the bunch is the Hahn Precision adapter blocks . If you google pictures you will see their feed ramp . Makes it more forgiving in placement of block in the mag well. Other styles can be finicky where you lock them down at for some magazines

The Hahn is available as bottom load, top load and dedicated blocks

As far as trigger goes, if you plan to use lower for anything else and want to have a good aftermarket trigger ( geissele , Timney , RRA 2 stage etc ) then have your bolt ramped

If you don't want to have your bolt ramped , or you don't plan to have any aftermarket trigger that does not use std hammer, then easiest and cheapest is a 9mm hammer from RRA .

A ramped bolt also has benefit of being more gentle on hammer pin

Buffers

RRA / Colt 9mm buffers IIRC are about 5.6Oz so close enough to the H3

I run both H3 and Enidine when using my 9mm upper

While on subject of buffers , if you plan to buy a new buffer, you should look at the "extended " buffers like the Spikes ST-9X

The extended buffer limits the overtravel of the bolt . Since the 9mm is so short it doesn't need full travel . Problem is that the 9mm setups can break bolt catches . The shorter travel minimizes the run up before it slams the bolt catch . If you pull back the charging handle on 9mm you can see the bolt face almost an inch away form stop !

Lots of people sell buffer spacers that do the same thing as extended buffer .

http:/ w.shop.masdefense.com/9MM-BUFFER-SPACER-AR15-9MM-BS.htm

htt newfrontierarmory.com/shop/buffer-spacer-9mm-40/

Lots of info online , from using rubber stoppers to a stack of quarters! I personally wouldn't do that
 
TRG-42 said:
Lots of companies make mag block adapter ( Pro Mag, Spikes, RRA , CMMG ) . The best of the bunch is the Hahn Precision adapter blocks . If you google pictures you will see their feed ramp . Makes it more forgiving in placement of block in the mag well. Other styles can be finicky where you lock them down at for some magazines

The Hahn is available as bottom load, top load and dedicated blocks

As far as trigger goes, if you plan to use lower for anything else and want to have a good aftermarket trigger ( geissele , Timney , RRA 2 stage etc ) then have your bolt ramped

If you don't want to have your bolt ramped , or you don't plan to have any aftermarket trigger that does not use std hammer, then easiest and cheapest is a 9mm hammer from RRA .

A ramped bolt also has benefit of being more gentle on hammer pin

Buffers

RRA / Colt 9mm buffers IIRC are about 5.6Oz so close enough to the H3

I run both H3 and Enidine when using my 9mm upper

While on subject of buffers , if you plan to buy a new buffer, you should look at the "extended " buffers like the Spikes ST-9X

The extended buffer limits the overtravel of the bolt . Since the 9mm is so short it doesn't need full travel . Problem is that the 9mm setups can break bolt catches . The shorter travel minimizes the run up before it slams the bolt catch . If you pull back the charging handle on 9mm you can see the bolt face almost an inch away form stop !

Lots of people sell buffer spacers that do the same thing as extended buffer .

http:/ w.shop.masdefense.com/9MM-BUFFER-SPACER-AR15-9MM-BS.htm

htt newfrontierarmory.com/shop/buffer-spacer-9mm-40/

Lots of info online , from using rubber stoppers to a stack of quarters! I personally wouldn't do that
Click to expand...

I am currently building a QC10 dedicated 9mm lower AR, I bought the bolt from them also. They recommended CMC triggers, they say they work well in their 9mm setups. I wanted to use Geissele but they say they dont work with their bolt, no biggie it forces me to try another trigger brand/model

As for a buffer Im going to try this hydraulic 9mm buffer from Blitzkrieg, QC10 told me they work very well in the 9mm setups to reduce recoil and soften the buffer slamming the back of the buffer tube and jumping past or damaging the bolt catch without a spacer

On the expensive side but will see what all the hype is about

https://www.blitzkriegcomponents.com/ProductDetails.asp?ProductCode=AR15-KYNJP-9P

https://www.youtube.com/watch?v=F-9WeeamH94
 
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