9mm Carbine build questions

WeedWacker · November 5, 2009, 07:34 AM

I have decided to build an AR-15 9mm carbine with the actual intent to turn it into an SBR. My questions here do not pertain to anything NFA (yet) but I'm just trying to make sure I have everything that I need before trying this build.

I have a T-15 stripped lower and I am looking at a CMMG 7.5in 9mm upper

http://cmmginc.secure-mall.com/shop/...80733&cat=173&

it says "Do not use with the dedicated 9mm hammer"

Is this a good thing? Should I get something that's "dedicated" or is this fine? It would certainly simplify things.

From what I see I need a mag block for the 9mm, any recommendations on mfg? Is it semi-permanent with tools or a drop in thing?

I think that does it for now, I have a few NFA quesitons but I will post those later when the project starts to take form.

rjrivero · November 5, 2009, 09:50 AM

Hillarious.

My current project is the exact same as yours.

The most popular, by far is the colt 9mm conversion, and similar. (Colt, Rock River Arms, Spikes Tactical all use the same type bolt.)

These 9mm carbines use the double feed "UZI style" magazines. You can get a mag well adapter from Rock River Arms, and it runs about $125. You then can use your standard lower, provided it doesn't have a "hook" on the hammer. The "hooked" hammer tends to cock very prematurely, and is rough on the hammer pin.

A few manufacturers are currently "ramping" the bolt group to limit the "early cocking" and beating up of the hammer pin, at best. At worst, the hammer could bind the bolt and lock up the gun. You definately DON'T want to do THAT!!! They claim no need to use a "dedicated" 9mm hammer. However, the hammer from Rock River can drop in to most lowers and be used for both 9mm and .223/5.53 uppers.

There are some other uppers, from olympic arms that use single feed STEN magazines. Some folks also make receiver blocks for these magazines, but it is by far less popular than the Colt Conversion style.

Enter the "new" lowers that use GLOCK style (up to 33 Round) magazines. They are SINGLE PURPOSE lowers that have been re-designed for the GLOCK magazines. Up till recently, only OLYMPIC ARMS made assembled rifles. You couldn't get just the lowers.

Right now, LONE WOLF DISTRIBUTERS is making dedicated GLOCK magazine lowers. (Currently back orderd for 2-3 months.)

I decided to go with the LONE WOLF LOWERS so I can use the Carbine with magazines compatible with my handguns. A BIG PLUS in my book. I also think the 9mm makes a great carbine rifle. You get a pretty good boost in performance from a 7-10" barrel, and it's still short and quick pointing, plus a huge capcity, not to mention relatively cheap to shoot.

As far as the NFA stuff goes, A Short Barrel Rifle with a Silencer......How sweet is that going to be?

WeedWacker · November 6, 2009, 02:27 AM

Now I notice you mentioned that different uppers can take different magazines, when it comes to the mags I would like to keep costs down, like $35 XD mags vs $15 Glock mags. What magazines exactly does the CMMG upper I listed above take? I couldn't find any info on it other than CMMG carries a lower that takes Uzi/Colt mags which I would take to imply that the upper would be best matched with those vs the Sten mags.

I am a little confused from your post though, the CMMG specifically says "Do not use with dedicated 9mm hammer" as if either excessive wear, voided warranty, or break/stoppage could occur with the use of such a hammer...

Questions leading to more questions is good though, gives me a better picture. Thanks for your reply!

TRguy · November 6, 2009, 05:57 PM

Ramped 9mm Bolt uses a standard AR-15 or M16 hammer

No need for special hammer

http://cmmginc.secure-mall.com/shop/?shop=1&cat=173&

I like the Lone Wolf lower that uses Glock Mags

http://www.lonewolfdist.com/Detail.aspx?PROD=1803

WeedWacker · November 7, 2009, 07:39 AM

After reading the LWD site it seems the Lone Wolf lowers are not compatible with all 9mm uppers. This would limit my prospects and would seem to be the only downside to me. However, my desire is to create an SBR 9mm and also leave me the option of creating a 5.56 SBR should I choose to do so later on. But I like the idea of the Wolf since it allows me to use the Glock mags. If they weren't back ordered on them I might consider going ahead and going that way right now. Anyone know how the turnaround is on NFA stamps and paper work now? I suppose I need to start asking around in the NFA forum.

rjrivero · November 7, 2009, 02:24 PM

The Lone Wolf Lowers will require a little modifying of the bolt on Colt style uppers. You will need to mill the bottom of the bolt so that it will pass between the feed lips of the narrow, single feed glock magazines. However, if you use GLOCK .40 caliber magazines loaded with 9mm rounds, it'll work without modifications.

November 5, 2009, 07:34 AM	#1
WeedWacker Senior Member Join Date: December 13, 2006 Location: Body: Clarkston, Washington. Soul: LaCrosse, Wisconsin Posts: 1,157	9mm Carbine build questions I have decided to build an AR-15 9mm carbine with the actual intent to turn it into an SBR. My questions here do not pertain to anything NFA (yet) but I'm just trying to make sure I have everything that I need before trying this build. I have a T-15 stripped lower and I am looking at a CMMG 7.5in 9mm upper http://cmmginc.secure-mall.com/shop/...80733&cat=173& it says "Do not use with the dedicated 9mm hammer" Is this a good thing? Should I get something that's "dedicated" or is this fine? It would certainly simplify things. From what I see I need a mag block for the 9mm, any recommendations on mfg? Is it semi-permanent with tools or a drop in thing? I think that does it for now, I have a few NFA quesitons but I will post those later when the project starts to take form. __________________ ()() ( '.') o( ()() (>'.')>PETA: PEOPLE EATING TASTY ANIMALS<('.'<) Last edited by WeedWacker; November 5, 2009 at 07:34 AM. Reason: Clarification

November 5, 2009, 09:50 AM	#2
rjrivero Senior Member Join Date: November 17, 2008 Location: NW Ohio Posts: 409	Hillarious. My current project is the exact same as yours. The most popular, by far is the colt 9mm conversion, and similar. (Colt, Rock River Arms, Spikes Tactical all use the same type bolt.) These 9mm carbines use the double feed "UZI style" magazines. You can get a mag well adapter from Rock River Arms, and it runs about $125. You then can use your standard lower, provided it doesn't have a "hook" on the hammer. The "hooked" hammer tends to cock very prematurely, and is rough on the hammer pin. A few manufacturers are currently "ramping" the bolt group to limit the "early cocking" and beating up of the hammer pin, at best. At worst, the hammer could bind the bolt and lock up the gun. You definately DON'T want to do THAT!!! They claim no need to use a "dedicated" 9mm hammer. However, the hammer from Rock River can drop in to most lowers and be used for both 9mm and .223/5.53 uppers. There are some other uppers, from olympic arms that use single feed STEN magazines. Some folks also make receiver blocks for these magazines, but it is by far less popular than the Colt Conversion style. Enter the "new" lowers that use GLOCK style (up to 33 Round) magazines. They are SINGLE PURPOSE lowers that have been re-designed for the GLOCK magazines. Up till recently, only OLYMPIC ARMS made assembled rifles. You couldn't get just the lowers. Right now, LONE WOLF DISTRIBUTERS is making dedicated GLOCK magazine lowers. (Currently back orderd for 2-3 months.) I decided to go with the LONE WOLF LOWERS so I can use the Carbine with magazines compatible with my handguns. A BIG PLUS in my book. I also think the 9mm makes a great carbine rifle. You get a pretty good boost in performance from a 7-10" barrel, and it's still short and quick pointing, plus a huge capcity, not to mention relatively cheap to shoot. As far as the NFA stuff goes, A Short Barrel Rifle with a Silencer......How sweet is that going to be? Last edited by rjrivero; November 5, 2009 at 10:07 AM.

November 6, 2009, 02:27 AM	#3
WeedWacker Senior Member Join Date: December 13, 2006 Location: Body: Clarkston, Washington. Soul: LaCrosse, Wisconsin Posts: 1,157	Now I notice you mentioned that different uppers can take different magazines, when it comes to the mags I would like to keep costs down, like $35 XD mags vs $15 Glock mags. What magazines exactly does the CMMG upper I listed above take? I couldn't find any info on it other than CMMG carries a lower that takes Uzi/Colt mags which I would take to imply that the upper would be best matched with those vs the Sten mags. I am a little confused from your post though, the CMMG specifically says "Do not use with dedicated 9mm hammer" as if either excessive wear, voided warranty, or break/stoppage could occur with the use of such a hammer... Questions leading to more questions is good though, gives me a better picture. Thanks for your reply! __________________ ()() ( '.') o( ()() (>'.')>PETA: PEOPLE EATING TASTY ANIMALS<('.'<)

November 6, 2009, 05:57 PM	#4
TRguy Senior Member Join Date: July 15, 2008 Location: Concord, NC Posts: 210	Ramped 9mm Bolt uses a standard AR-15 or M16 hammer No need for special hammer http://cmmginc.secure-mall.com/shop/?shop=1&cat=173& I like the Lone Wolf lower that uses Glock Mags http://www.lonewolfdist.com/Detail.aspx?PROD=1803 __________________ For the Fellow Carolina Folks: www.carolinaguntalk.com

November 7, 2009, 07:39 AM	#5
WeedWacker Senior Member Join Date: December 13, 2006 Location: Body: Clarkston, Washington. Soul: LaCrosse, Wisconsin Posts: 1,157	After reading the LWD site it seems the Lone Wolf lowers are not compatible with all 9mm uppers. This would limit my prospects and would seem to be the only downside to me. However, my desire is to create an SBR 9mm and also leave me the option of creating a 5.56 SBR should I choose to do so later on. But I like the idea of the Wolf since it allows me to use the Glock mags. If they weren't back ordered on them I might consider going ahead and going that way right now. Anyone know how the turnaround is on NFA stamps and paper work now? I suppose I need to start asking around in the NFA forum. __________________ ()() ( '.') o( ()() (>'.')>PETA: PEOPLE EATING TASTY ANIMALS<('.'<)

November 7, 2009, 02:24 PM	#6
rjrivero Senior Member Join Date: November 17, 2008 Location: NW Ohio Posts: 409	The Lone Wolf Lowers will require a little modifying of the bolt on Colt style uppers. You will need to mill the bottom of the bolt so that it will pass between the feed lips of the narrow, single feed glock magazines. However, if you use GLOCK .40 caliber magazines loaded with 9mm rounds, it'll work without modifications.