So I have a lower and upper all set to go with a lower parts kit, upper, standard at upper parts kit. No bolt, barrel, gas system. What parts would I need to get for a 16" barrel carbine system? First I need a 9mm chambered barrel with barrel extension(suggestions for all listed?), a 9mm AR bolt, a 9mm ejection port adapter kit, a magazine well adapter, break/compensator, 9mm magazines. Is that everything besides handguard? 9mm are blowback only do no gas system correct? I would need a 9mm buffer to replace my standard carbine one? Anything else? Any tricks, suggestions, pitfalls, common issues? Just anything that would help me complete the build? Thanks!!
Building an AR-15 in 9mm Help!
- Thread starter mookiie
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Let's see.
You will need a barrel. I got mine from MAS Defense. It works fine, and was priced well. There are others out there. CMMG, I think. RRA and YHM all have good barrels.
Muzzle device of your choice. Doesn't matter, just make sure the threads match.
Are you going to run Iron sights? If so you'll need a gas block/front sight base. If mounting the sights on a rail, you can skip that.
Bolt. There are two kinds. Ramped and unramped. I recommend ramped, because it lets you use a standard LPK. The place I got mine from closed, which is a shame cause it's a nice bolt. But good makers abound. Again, CMMG, YHM, MAS Defense, I think PSA sells one now, JSE Surplus.
Buffer: A standard buffer lets a 9mm bolt go back farther than it needs to so it picks up some speed before it hits the bolt catch, This will lead to the bolt catch breaking over time. To combat this you can either get a spacer that goes behind the buffer spring, or buy an extended length buffer. The spacer is by far cheaper if you have a buffer from your lower kit. The 9mm Buffer is pricy, but heavy, and a one piece solution. I did a Spikes long 9mm Buffer, and have had no problems. 9mmar.com sells a bunch of buffers.
Magwell Block: Don't skimp here. Whether or not your 9mm AR is reliable depends a lot on what is holding the mags in place. There are essentially two types. Top loading, and bottom loading. (That refers to how the magwell blocks go in, not the mags.) Top loading are easier to index, less adjustable and harder to take out. Bottom loading blocks are harder to install, more adjustable, and easier to get out.
For top loading Hahn Precision is kinda the go to. For bottom loading, Hahn (bottom loading) or Spikes enhanced. Either one is going to set you back between $150 and $200. Don't buy the Pro-Mag or the C-Products.
Gas Deflector: You don't NEED a gas deflector, I run a slickside upper on mine with no door or deflector and am fine. But if you want one, you can throw one on. They usually come with the little half door that goes with them. I think they are as ugly as sin.
You'll need some mags. Make sure whichever mag block you get works with your mags. I like the Colt pattern.
Depending on which mag block you get, you might need a 9mm bolt catch.
Handguard/rail system of your choice.
That should do it.
Gratuitous pic:
You will need a barrel. I got mine from MAS Defense. It works fine, and was priced well. There are others out there. CMMG, I think. RRA and YHM all have good barrels.
Muzzle device of your choice. Doesn't matter, just make sure the threads match.
Are you going to run Iron sights? If so you'll need a gas block/front sight base. If mounting the sights on a rail, you can skip that.
Bolt. There are two kinds. Ramped and unramped. I recommend ramped, because it lets you use a standard LPK. The place I got mine from closed, which is a shame cause it's a nice bolt. But good makers abound. Again, CMMG, YHM, MAS Defense, I think PSA sells one now, JSE Surplus.
Buffer: A standard buffer lets a 9mm bolt go back farther than it needs to so it picks up some speed before it hits the bolt catch, This will lead to the bolt catch breaking over time. To combat this you can either get a spacer that goes behind the buffer spring, or buy an extended length buffer. The spacer is by far cheaper if you have a buffer from your lower kit. The 9mm Buffer is pricy, but heavy, and a one piece solution. I did a Spikes long 9mm Buffer, and have had no problems. 9mmar.com sells a bunch of buffers.
Magwell Block: Don't skimp here. Whether or not your 9mm AR is reliable depends a lot on what is holding the mags in place. There are essentially two types. Top loading, and bottom loading. (That refers to how the magwell blocks go in, not the mags.) Top loading are easier to index, less adjustable and harder to take out. Bottom loading blocks are harder to install, more adjustable, and easier to get out.
For top loading Hahn Precision is kinda the go to. For bottom loading, Hahn (bottom loading) or Spikes enhanced. Either one is going to set you back between $150 and $200. Don't buy the Pro-Mag or the C-Products.
Gas Deflector: You don't NEED a gas deflector, I run a slickside upper on mine with no door or deflector and am fine. But if you want one, you can throw one on. They usually come with the little half door that goes with them. I think they are as ugly as sin.
You'll need some mags. Make sure whichever mag block you get works with your mags. I like the Colt pattern.
Depending on which mag block you get, you might need a 9mm bolt catch.
Handguard/rail system of your choice.
That should do it.
Gratuitous pic:
@Dogmush, thank you for the well informed reply I will start looking for the parts and may hit you up for opinions/recommendations if I get stick or unsure what product to go with. Which mag well do you recommend top/botoom loading and brand?
Thanks a lot!
Sean
Thanks a lot!
Sean
I went with a Spike's. I wanted to be able to take it in and put, as I dropped a tax stamp on that lower.
If I knew for sure I wasn't going to change the caliber often, I would go with the Hahn top loading. All depends on your plans for the rifle.
The only real "issue" I ran into was setting up the magwell. When installed flush mine rubs the bottom of the bolt. So I had to spend an half an hour or so getting it to feed just right with ball and hollowpoints. Lower a little, test. Raise a little, test. Change bullets, test. I did that at home, and my first range trip (and all subsequent ones actually) was trouble free.
If I knew for sure I wasn't going to change the caliber often, I would go with the Hahn top loading. All depends on your plans for the rifle.
The only real "issue" I ran into was setting up the magwell. When installed flush mine rubs the bottom of the bolt. So I had to spend an half an hour or so getting it to feed just right with ball and hollowpoints. Lower a little, test. Raise a little, test. Change bullets, test. I did that at home, and my first range trip (and all subsequent ones actually) was trouble free.
By the way that is a nice looking firearm! One question I have always had regarding tax stamp items is for the above is do you build upper/lower then send in for stamp, or can you only build the lower till you get a stamp? How exactly does that work?
Then I would look at this one:
http://stores.9mmar.com/hahn-precision-dedicated-9mm-magwell-block/
As far as the stamp, as you can see from that pic, I built a pistol, dropped the stamp, and had fun shooting it until the stamp came in. On other stamps I waited until I had all the paperwork before I started the build.
You can do whichever you want as long as you don't build an NFA configuration untill you have your stamp in hand.
Arizona_Mike
Member
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Standard 9mm bolt needs a 9mm hammer. Ramped bolt can use a standard hammer.
Pay attention to muzzle threads. 1/2-28 is a standard thread for 5.56 rifle and 9mm handguns but a number of commercial rifle makers won't sell you a 1/2-28 threaded rifle muzzle and if you go a custom barrel route as I did, you may have trouble finding 1/2-28 threaded muzzle attachments. You can get an A1 style birdcage from Lage Manufacturing (they use 1/2-28 threads on their .380 and 9mm machine gun uppers)--other companies that used to sell them have stopped--I have not been able to find a source of an A2 anywhere. No one wants to even be tangentially involved with someone who threads a 5.56 muzzle device on a 9mm rifle.
If you want a brake this might be a good option: https://www.lonewolfdist.com/Detail.aspx?PROD=187390&TERM=muzzle
Adapter blocks can be very picky about which mags they work with and which they don't--it's not just an issue of mag quality but compatibility. Search my past posts about my issues. My Hahn bottom loader works great with Metalforms but not C-Mags. Also only some adapter/mag/hold open catch combinations allow LRHO.
I had a lot of trouble getting the disconnector to work on my match grade trigger (due to me wanting to use a single SBR lower for everything). I had to move the rear takedown pin hold upward a bit to get the hammer down far enough with the ramped bolt that the disconnector would engage with the gun in any orientation--it was about 40 thousandths. Again documented in my old posts.
The heavier the bolt and carrier the better. The 9mm AR runs at very fast slide velocities which is hard on the gun, hard on the brass, and will run dirty. Most successful blow-back guns have slide velocities of around 4m/s. I've managed to get my AR down to about 6m/s with a very heavy extended buffer (and the gun runs noticeably cleaner as well). A longer than normal buffer will keep the slide from getting to much of a running start against the bolt catch (9mm ARs tend to brake a lot of these parts).
Mike
Pay attention to muzzle threads. 1/2-28 is a standard thread for 5.56 rifle and 9mm handguns but a number of commercial rifle makers won't sell you a 1/2-28 threaded rifle muzzle and if you go a custom barrel route as I did, you may have trouble finding 1/2-28 threaded muzzle attachments. You can get an A1 style birdcage from Lage Manufacturing (they use 1/2-28 threads on their .380 and 9mm machine gun uppers)--other companies that used to sell them have stopped--I have not been able to find a source of an A2 anywhere. No one wants to even be tangentially involved with someone who threads a 5.56 muzzle device on a 9mm rifle.
If you want a brake this might be a good option: https://www.lonewolfdist.com/Detail.aspx?PROD=187390&TERM=muzzleAdapter blocks can be very picky about which mags they work with and which they don't--it's not just an issue of mag quality but compatibility. Search my past posts about my issues. My Hahn bottom loader works great with Metalforms but not C-Mags. Also only some adapter/mag/hold open catch combinations allow LRHO.
I had a lot of trouble getting the disconnector to work on my match grade trigger (due to me wanting to use a single SBR lower for everything). I had to move the rear takedown pin hold upward a bit to get the hammer down far enough with the ramped bolt that the disconnector would engage with the gun in any orientation--it was about 40 thousandths. Again documented in my old posts.
The heavier the bolt and carrier the better. The 9mm AR runs at very fast slide velocities which is hard on the gun, hard on the brass, and will run dirty. Most successful blow-back guns have slide velocities of around 4m/s. I've managed to get my AR down to about 6m/s with a very heavy extended buffer (and the gun runs noticeably cleaner as well). A longer than normal buffer will keep the slide from getting to much of a running start against the bolt catch (9mm ARs tend to brake a lot of these parts).
Mike
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Zach S
Member
While the Slash buffer, or one of its copies, would be the best buffer choice, a cheap spacer can be made for about $2.25. In quarters...
Simply remove the buffer and spring, drop nine quarters in, and replace the buffer and spring...
As for the mag block, I think I used what Hahn calls a "top load." It has no provision for a BHO, and is relieved on the back so it can be loaded without removing the 5.56 bolt catch. You can have a functional BHO, but to do so, you have to replace the 5.56 bolt catch with the 9mm specific part.
For magazines, I stick with Colt/Metalform, or Brownells. Promags are crap, CProducts are marginally better than crap. Mine function 100%, but I modified the followers and can't remember how.
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Arizona_Mike
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- Feb 15, 2013
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My Hahn bottom loader has a siding part that allows a standard AR15 bolt catch.
I think the final generation of C-Mags (red follower) are very high quality but the geometry is off for the Hahn block. I measured about 50/1000 of an inch in how high they sit relative to the feed ramp. I don't like how flimsy the little welded on LRHO tab is on the Metalforms. Of my first 5-6 mags from Brownell’s, one had a tab broken in shipment. However, they feed reliably.
Mike
I think the final generation of C-Mags (red follower) are very high quality but the geometry is off for the Hahn block. I measured about 50/1000 of an inch in how high they sit relative to the feed ramp. I don't like how flimsy the little welded on LRHO tab is on the Metalforms. Of my first 5-6 mags from Brownell’s, one had a tab broken in shipment. However, they feed reliably.
Mike
wally
Member
I agree they are ugly, but if you plan on shooting suppressed I think you'd appreciate having one, especially if shooting left-handed.
I am left handed, however I don't suppress mine. So far I haven't gotten any more gas to the face with the 9mm than I get with a 10.5" 5.56.
I am using a short barrel, heavy bolt and buffer, and strong spring however. All that helps minimize face gas.
A 16" with a can may very well be a different animal.
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