Author Topic: Anyone here with a 9MM AR15? I'm thinking of building one.  (Read 1106 times)

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Offline M1A4ME

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Anyone here with a 9MM AR15? I'm thinking of building one.
« on: January 24, 2018, 07:39:05 PM »
I know, it's going to be darned expensive to get what I want, the way I want it.

I don't want one of those leaning magazine Glock things.  I want a lower/bolt that use the Colt style magazines.

My idea is to build a 9MM pistol.

I want one that locks the bolt back when the magazine is empty.

I want about a 10" barrel (reason for that is I want to eventually buy/permanently mount a suppressor that puts the overall barrel length over 16", so I can put a butt stock on it and be legal - yeah, it'll be a pistol with a pistol buffer tube till then).

I want a free float tube, for back up sights and a red dot optic.

Anyone else have one/build one?  Good and bad on them?

Thanks.  Oh, this won't be a quick one.  Between the cost and the suppressor/paperwork/approval it will be awhile before it's done (stage 1 = pistol, stage 2 = suppressed carbine.)

Oh, why the AR15 9MM carbine?  To keep parts and manual of arms like the AR15's we currently shoot more than anything else.  Why the Colt magazine version vs. the Glock?  I don't own a Glock 9 (.357 SIG/.40 S&W, yes), have no magazines for them and the full sized Glock 9mm magazines are about the same cost (or more) than the full sized Colt style 9MM magazines.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline 2morechains

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #1 on: January 24, 2018, 09:16:32 PM »
I built one back in 2016.  Started out as a pistol with 7.5” bbl, pistol buffer tube and a Sig Brace, then when PCC became a division in USPSA I converted it to a rifle with a real butt stock and 16” bbl and added a longer FF handguard. 

I built mine on a dedicated 9mm lower using a Quarter Circle 10 (QC-10) lower that accepts Colt SMG mags.  The lower is not cheap, but then again a quality conversion block for a regular AR-15 are not cheap either.  Since then a number of other manufacturers have come out with dedicated 9mm lowers (NFA, PSA, Nordic, etc.). The only 9mm specific parts on a AR9 are the barrel, bolt, maybe the buffer, and either the dedicated lower or a conversion block.  All the other parts are AR15 compatible (handguard, upper, buffer tube, trigger, etc).  The QC-10 has last round bolt hold open (LRBHO). 

I put a 13” freefloat handguard on it, Magpul K2 grip (prefer the more verticle), and a 6MOA C-More red dot and I was off and running with it.  As things progressed, made a few competition specific changes:  Added a second red dot sight on a 45 deg mount for the hard left leans, and upgraded my barrel to a Taccom ULW (5.5” barrel with an aluminum sleeve to make it 16.1”) to drop some weight and speed up transitions.  been very happy with the Taccom barrel. 

Pros:  AR9s are fun to shoot, cheaper ammo than .223, and USPSA has a division for them which has garnered quite a bit of interest within the competition circles. Did I mention fun?  32-round Metalform mags can be had for $20, and I added a +10 extension from TaylorFreelance for a total of 42 rounds.  No reloading on the clock for me unless the stage requires it. 

Cons:  Most AR9s are blowback design with a one piece heavy bolt.  The recoil impulse is actually a little more than .223 and can cause the dot to bounce on firing more than I like.  Unlike an AR15 with the two piece BCG, the AR9 uses a one piece bolt that is neccessarily heavy to keep the bolt in place long enough for the pressure to drop after ignition before it starts coming back (blowback design).  Along those lines, the buffer needs to be a little heavier than a .223 carbine buffer tho some people get by with a standard carbine buffer.  In the last year or so there’s been a lot of experimentation and innovation to come up with the ultimate buffer/bolt/spring combination that results in minimal recoil and “dot bounce” for staying on target during rapid shooting.  I’m not entirely certain there’s the right answer for every application as it depends on a number of variables (ammo, weight of gun, shooter skill, what kind of shooting you’re doing...).  That said, I started out with a heavy CMMG bolt and 8 oz Spikes buffer and Tubbs Flatwire buffer spring.  That lasted about 6 months then my bolt went TU so I switched to the JP bolt and SCS buffer system and called it good.  Taccom, Blitzkrieg, MBX all have their pet buffer systems, and it would take a heads up comparison to figure out which one you like.  So good news, a lot of options if you’re trying to tone down the recoil/dot bounce, bad news is you literally need to try it for yourself. 


Offline John A.

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #2 on: January 24, 2018, 10:06:58 PM »
I made an integral 9mm firearm.

What exactly would you like to know?

There are 2 main types that will hold the bolt open.

Colt style and glock style ;)

Colt, Metalform and Tavor mags have bolt hold open followers.  I think ASC do too.  But stick with the metalform or tavor mags if you can. 

I often use uzi mags, which honestly don't hold the bolt open when empty, but I have a lot of them since I have 2 other subguns that use them already.

Mine has been very reliable.  Not gassy at all, despite the integral can.  (the entire freefloat forend is the silencer body).  It has a ton of room inside for gas to expand and cool.

And it's very quiet.



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Offline fatboy

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #3 on: January 24, 2018, 11:14:22 PM »
Built a plain jane with Spikes lower, mag adapter and fixed entry stock. Plastic magpul BUIS, magpul 2 point, extended mag and bolt release, topped with a sparc ar 1/3 CW (home defense, not a long rang tac driver). Use the metal colt mags, the plastic ones are not real smooth going in or out. I hear modified UZI mags work as well.

Handy for a 100lb wife if I need some Shockwave backup (we all use a handgun in the house for protection while getting our rifles, right?).

Runs like a Singer sewing machine and very light recoil.

"Plain Jane" != "cheap" except to feed.

We all have some flavor of the SMG.

Have fun with your build!
25, with 35 years experience

Offline M1A4ME

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #4 on: January 25, 2018, 06:16:00 AM »
John A., did you build/make the silencer or buy it?

I thought about a magazine block and a standard AR15 lower receiver but after looking at prices (and thinking about just being able to look at it and know it's the 9 and not one of the AR's) I'm thinking about a dedicated 9MM lower.  I almost bought a Spikes Tactical lower yesterday.

Right now, the 9MM parts and the AR15 parts are priced so differently (9MM lower about 3 to 4 times more than an AR15/.223 lower, 9MM bolt 2X, or more, what a .223 bolt costs) that I realize it'll be a slower build.

The comments about low recoil are interesting as some people report higher recoil.  Lower recoil is one of the reasons for this new build.  Stage 1 would just be the 9MM AR pistol, so no big deal.  Stage 2, if I get that far, would involve the tax stamp, a trust so my wife would be legal using it, too, and the cost of the silencer and the permanent attachment to the barrel so I could put the carbine butt stock on it.

Just have to get the right parts since some parts seem to be made for use with Glock magazines, some for use with the Colt style magazines and some are supposed to work with either.

The "build" will be fun, they always are. 
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline John A.

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #5 on: January 25, 2018, 10:08:33 AM »
I made it.

For years, I had wanted to go that route, but I designed it similar to the WW2 Delisle, with the exception of the offset bore that it uses.  Otherwise, it is very similar in many outward respects.

The Baffles themselves are also different.

I wouldn't mind sharing a few photos in PM if you're wanting a peek under the hood ;) .

To the subject of recoil.

Recoil is somewhat subjective.  I own at least 5 different 9mm pistol cal guns.  They all feel a little "different" than the others.  None really what I would call "objective".

My 9mm AR seems to have less recoil than the scorpion.  Slightly more than the mp5.  Just to put it into comparison.

A 10 year old can easily use it.

There are many different 9mm buffers out there too ranging from 5 oz to 8 oz.  Maybe that's why I hear so many different responses concerning how it "feels" to shoot.

And I'm also using a superior shooting brand flat coil chrome silicone buffer spring, which works very well in my buffer tube.

Mine has a standard AR receiver and an AMM magblock.  AMM is no longer in business that I know of, but it's based on the 2gen Colt design, which does have a mag block lever built it that helps the uzi followers stop the bolt when empty.

RRA mag block also does, and the bottom loading Hahn block does too off the top of my head.

But the price of the mag blocks alone cost as much as the new glock style receivers themselves. 


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Offline M1A4ME

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #6 on: January 25, 2018, 02:32:06 PM »
Thanks John A. 

I'm not sure I'm up to building something like that.  It might require some tools I wouldn't use very often.

Another question popped into my head?

Standard AR15 upper receiver?  Slick side (no bolt assist) upper receiver?  Or one of the dedicated 9MM upper receivers?

I'm leaning towards a "slick slide" upper if I can find one at a decent price.  But I'm not sure what/why others have used.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline John A.

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #7 on: January 25, 2018, 04:26:11 PM »
9mm bolts don't have forward assist notches, so that much is moot.

You can still have an upper that has a forward assist on it of course, but they aren't functional.  Extra weight and bulk for nothing.

Mine is a slickside upper.

No forward assist, no dust cover.

Why?

Because the 9mm isn't like rifle calibers. 

9mm AR ejection port for instance doesn't need all the space that rifle calibers need to eject an empty.   The empty 9mm cases are 3/4" long maybe?  Half the length of a standard 223 case.

That's why RRA 9mm uppers blocks the entire rear half of their ejection port with their shell deflector.  (another thing that isn't really needed because a 9mm casing will never physically touch the shell deflector on a standard AR upper).

Having a slickside takes away nothing, and doesn't add anything unnecessary in the process.

Slickside is perfectly acceptable.  I think you're on the right track.

« Last Edit: January 25, 2018, 04:35:04 PM by John A. »
When people ignorant of guns make gun laws, you end up with ignorant gun laws.

Offline swede69

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #8 on: January 25, 2018, 10:27:37 PM »
I used a quarter circle 10 lower colt style with jp bolt and buffer and a nice side charging upper by Gibbz Arms. They all make s top shelf products. And it runs great but get yourself a mag loader  from maglula because  your thumbs will get destroyed on the first day.

Offline M1A4ME

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #9 on: January 26, 2018, 06:23:54 AM »
I never felt the need for a magazine loader till I got the Browning BDM 9MM and the ParaOrdnance P14.  Then I bought a mag lula and it worked so well I got a few more for the sons/nephew and for me to carry one in the range bag and one in the target bag.  Ain't they great! 
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline M1A4ME

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #10 on: January 28, 2018, 08:55:17 AM »
Well, Spikes Tactical 9MM lower (for Colt style magazines) ordered.  I'll pick it up when my FFl calls to let me know it has arrived.

Also ordered some lower parts and three magazines.

I have just had a thought (triggered by a 9mm/147 grain request for load recommendations I saw on another forum) about powders/bullets and a blowback action like this AR 9MM will have.  I think maybe I'll start a different thread for that as it's a reloading/ammo question/philosophy/experience thing.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline M1A4ME

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #11 on: January 28, 2018, 08:58:25 AM »
Oh, one other thing/question.

Magazines.  Any problems with any particular brand.

I missed the opportunity to by some metalform magazines on sale at CDNN.

I ended up ordering three ASC 32 round magazines as a start.  I've heard they were okay (didn't do a lot of research, just heard that).

I've also heard the CProducts 32 round magazines are hit or miss.  Work fine for some people, not so much for others.

Not sure how many other makers of Colt style 9MM magazines are out there or how they perform.

Any experience here, with the different brands?
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline John A.

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #12 on: January 28, 2018, 11:25:54 AM »
I have an ASC mag.  It is "okay". 

"okay for what"?

Range use. general use around the house.

For real use of HD, get at least one metalform, (they make the Colt) mags. 

Metalform might save you a dollar or two over the Colt name, but they're the same magazines.

If you can find good IWI Tavor 9mm magazines, they too are good mags and about $10 cheaper a pop. 

So, the 3 "really good" mags are metalform, colt, tavor in no particular order.  But expect to pay over $20-$30 a pop for either of the above.

I use modified uzi mags in mine mostly.  They dont' hold the bolt open when empty (they weren't made for that), but they work reliably.  The only thing I had to do to modify my uzi mags was mill a notch for the AR mag catch.

I have 3 guns that use uzi mags.  I already had a stack of mags, and they work well.  But like I said, I had to mill a notch for the mag catch.  No huge deal.

I have some 147 and 165 gr recipes that work really well in my 9 carbines and such if you want them.

« Last Edit: January 28, 2018, 11:34:29 AM by John A. »
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Offline 2morechains

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #13 on: January 28, 2018, 11:50:08 AM »
I use the Metalform mags.  Last ones I bought were from PSA when they were on sale for $20.  They’ve not given me any problems. 

Offline Atomic Punk

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Re: Anyone here with a 9MM AR15? I'm thinking of building one.
« Reply #14 on: January 28, 2018, 09:56:41 PM »
I have the SB Tactical PDW brace on my Nordic Components 22LR AR pistol and love it.

https://www.sb-tactical.com/product/sbpdw/

Unless ATF changes their mind (again), I won't be going the SBR route.

 

anything