SMG 9mm upper suggestions

[Pain103]

My searching around hasn't produced much results so any help would be appreciated. I'm looking for a barreled flat top upper for my Colt SMG. I would like to stay 10.5" and it has to be able to hold up to plenty of 3 round burst shooting.

Thanks for any help.

[Dolomite_supafly]

If you want I will build you a barrel. I can build it to YOUR specifications and configure it in any way you want. I can also thread it 1/2-28, versus, 1/2-36, to make silencer use a little easier.

 

All I need is for you to order one of these and mail it to me.

http://www.gmriflebarrel.com/9mm-blank-s-17-5-x-1-25-9mm-gunsmith-edition-raw-blank-1-10/

(I will send back any unused portion of the barrel for future use)

 

And for payment just add one of these to the order.

http://www.gmriflebarrel.com/7-62x51-blank-7-62x51-raw-blank-25-x-1-25/

 

I can also add cooling fins to the 9mm barrel if you like because it will be used with a MG. Like I said I will build it to your wants and can anywhere from mild to wild.

 

Only hang up is I am on the injured list until the end of June so I cannot do it until then.

[Dolomite_supafly]

I would STRONGLY suggest getting a ramped bolt when you do go to 9mm. Bolts that are not ramped cause the hammer pins to break and will egg shape the hammer and trigger pin holes. If you have a RDIAS then it isn't that big of a deal but if it is your lower that is the MG then it could destroy your lower.

[Pain103]

I was planning on using the bcg and charging handle from the stock upper. Would their be any issues doing that?

[Johnny Rotten]

Have you looked at CMMG?

ADCO uses their own barrel and a rock river upper I think, both use ramped bolts.

5​56 not fun enough? I've thought of doing 9mm for awhile just never got around to do it.

[Dolomite_supafly]

The BCG from a 5.56 AR will NOT work with a Colt pattern 9mm setup. Colt, and most other brands, 9mm ARs are typically blowback operated. Because they are blowback they do not require ports in the barrel, a gas tube or even a gas key on the carrier itself. The carrier is also weighted more heavily so it will work with the blowback setup.

 

Any blowback gun is going to be more reliable than a typical locked breech gun. It is also safer because if you have an over pressure round that just means the bolt will open a little sooner. And 9mm blowback makes an excellent training gun because the 9mm is cheaper to shoot and has more felt recoil than a 5.56. So you can train for recoil using cheap 9mm. And with the longer barrel the 9mm starts performing more like a 357 magnum and less like a 9mm pistol.

 

Another great thing about the extra recoil of a blowback gun is they are super easy for those of us who cannot afford a MG. I recently bought one of the $100 bumpfire stocks and it works great.

 

I built my wife a 9mm AR in 2003-2004 (can't remember exactly when) and it has been dead nuts reliable. As long as we are shooting ball ammunition her gun is 100% reliable but it is a semi auto as well. Hollow points are a bit more finicky so just plan on not using them. I use the Flex Tip ammunition for my defensive ammunition and it feeds perfectly. I recently built another 9mm AR that has a 3.5" barrel. I built it specifically for use with my 9mm silencer and it seems like a perfectly match setup. I threaded a pistol buffer tube for a YHM butt pad so the setup is short. I made the barrel from a Green Mountain blank. I have probably used 15 GM barrels for different projects now and they have always worked great. I will try to get a picture uploaded.

 

To convert a 5.56 AR to shoot 9mm you will need these items beyond what comes with a standard 5.56 AR.

1. 9mm barrel

2. 9mm blowback carrier that has been ramped

3. Magazine block for the lower

4. Magazine (Either Colt pattern or UZI magazines with the catch slot cut in)

5. Heavy buffer

6. Flash hider 1/2-36

7. 9mm hammer (some 9mm bolts do not work well with 5.56 hammers so you might have to buy one)

 

There are a couple of decent options on magazine blocks. Hahn is the Cadillac of conversion blocks but they are very EXPENSIVE. ProMag makes one as well but unlike their magazines the block itself works great. The ProMag magazine block drops in from the top of the lower and is held in place with the bolt hold open and magazine catch in the lower. So switching back and forth requires a bit more time, like 15 minutes, than just. Hahn makes a "temporary" magazine block that slides in from the bottom and is held in place with set screws. It works great but it will loosen over time leaving the magazine sitting a little too low to feed. So ALWAYS use the one the drops in from the top to prevent that.

 

If you need ANY help with getting your 9mm running, or with what you need to buy, please let me know.

[Pain103]

The bcg isn't from a standard rifle I have a complete Colt SMG from the factory I just want another barreled upper that is flat top to mount a red dot and flip up sights. I would want to use the bcg and charging handle that came with it from Colt.

[Dolomite_supafly]

Easy enough. Like I said I will build the barrel in any configuration you want. And if you want I will square up the upper receiver.

[Ropin4gold]

Man I have been wanting to build a 5.5" 9mm upper to go with my can in a bad way.