AR 15/9 question

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  • m.ammer69

    Member
    Jul 3, 2013
    76
    So I've been looking into purchasing an AR 15 and have stumbled upon the Ar15's chambered in 9mm. I've always been fascinated with the pistol caliber carbines and thought this would be perfect for me, I could get a pistol caliber carbine and have it look similar to the original m-16. I'm looking at trying to build one piece by piece to keep cost down. But I'm not to familiar with AR-15. I know they super customizable like the 1911 or Glocks, so I know there are tons of parts but I'm not sure how interchangeable these parts are from company to company. As well as if the parts are like a 1911, you have to essential file and mil them to fit your firearm or if it's like Glock and other composite firearms;where you just need to make sure the model,caliber and gen are correct and all the pieces will fit just fine.

    Summary
    1. How interchangeable are AR parts especially in 9mm? Ex. Do they need to be fitted or is it a plug and play situation?
    2. Is it worth trying to piece together one or should I just save up and wait for the right one? (I'm looking to build a 9mm carbine with the 16in barrel,that is similar to that of the 1960's m-16)
    3. Do you guys have any suggestions on places to get inexpensive AR-15 parts?
    4. Do you guys have any suggestions on manufacturers to stay away from and who to look for,for inexpensive parts.
     

    TheOriginalMexicanBob

    Ultimate Member
    Jul 2, 2017
    32,177
    Sun City West, AZ
    I think there are a fair amount of variables...and not every maker does the conversion the same way. I have a Colt 9mm Carbine...the receiver is all but the same as the 5.56 receiver but the magazine adapter is pinned in with stainless steel pins. I would think trying to install such pins without the appropriate fixtures would not be easy to do it correctly.

    Outside of the receiver mods and bolt and magazines the carbine is pretty much the same as the stock AR/M4. Maybe the recoil spring is different but I don't know if that is the case.
     

    outrider58

    Eats Bacon Raw
    MDS Supporter
    Jul 29, 2014
    49,816
    The two biggest hurdles will be putting a (faux)front sight block on the barrel. There is no gas journal step. You'd be better off buying a(good luck finding one) Colt upper. You will be forced to use pmags converted with Mean EndoMag conversion kits. A small price to pay. You will want to change out the buffer spring, buffer, as well as possibly a spacer in the buffer tube. Naturally, the bolt carrier group is different, but most will work with what I have already mentioned.

    https://www.meanarms.com/products/detail/endomag-9mm-restrictive-states

    https://www.colt.com/detail-page/colt-ar-15-semi-auto-9mm-161-301-rogers-4-pos-stock
     

    euler357

    ,
    Industry Partner
    MDS Supporter
    Apr 6, 2011
    584
    Odenton, Marylandistan
    I have built a few AR9s. I like using the Spike's Tactical lower since it has a decent LRBHO (last-round bolt hold open) mechanism built in and takes Glock mags. I've been using the AR-stoner EV2 billet uppers from MidwayUSA, Ruger trigger, and KVP linear comp on them. They have been running flawlessly.

    https://spikestactical.com/collections/lowers/9mm-spider-stripped-lower-receiver/
    https://www.midwayusa.com/s?searchTerm=ev2+9mm&perPage=48
    https://ruger.com/micros/AR-Trigger/index.html
    https://www.kawvalleyprecision.com/default.asp (some of these are too big to fit in the AR-Stoner handguard so measure)
     

    Enfield303

    Active Member
    Feb 12, 2011
    196
    Harford County
    I have used several of these 9mm magwell adapters for Colt pattern magazines. Fits easily into most lower receivers, doesn't require drilling or pinning. They are out of stock now but Midway had them just a week ago. If you live in a free state Promag makes a 50 round drum just for AR style rifles so there isn't a big gap between the mag well and the drum. I think it looks better too.

    https://www.midwayusa.com/product/1019567735?pid=900392

    For the upper, try Delta Team Tactical. Get a buffer that weighs at least 5.4 ounces. Even better are the longer buffers made just for 9mm.

    Some bolts only work with Glock mags and some only work with Colt there are bolts that work with both.

    For what its worth I really like 9mm ARs and prefer the Colt style magazine.
     

    outrider58

    Eats Bacon Raw
    MDS Supporter
    Jul 29, 2014
    49,816
    I prefer dedicated PC lowers for my pistol caliber lowers, but I am in the process of building a CMMG Banshee 9mm and I will be using a standard lower with converted Pmags. I'm just waiting on the 5" barrel and BCG. It will be bad ass!
     

    woodline

    Ultimate Member
    MDS Supporter
    Jan 8, 2017
    1,947
    I prefer dedicated PC lowers for my pistol caliber lowers, but I am in the process of building a CMMG Banshee 9mm and I will be using a standard lower with converted Pmags. I'm just waiting on the 5" barrel and BCG. It will be bad ass!
    I’m running an Amphibian build CMMG RDB setup (but with the 8” barrel) with a Dead Air Wolfman suppressor, and can confirm that it is indeed badass. Shot it side by side with a blowback AR9 and the difference was impressive. It’s not like either would bruise your shoulder, but the Amphibian setup is incredibly soft shooting, and smooth. The converted Pmags work great, and will allow me to use my normal gear for training.

    Will have to wait until I’m stateside again to compare it to an MP5 and MPX.
     

    outrider58

    Eats Bacon Raw
    MDS Supporter
    Jul 29, 2014
    49,816
    I’m running an Amphibian build CMMG RDB setup (but with the 8” barrel) with a Dead Air Wolfman suppressor, and can confirm that it is indeed badass. Shot it side by side with a blowback AR9 and the difference was impressive. It’s not like either would bruise your shoulder, but the Amphibian setup is incredibly soft shooting, and smooth. The converted Pmags work great, and will allow me to use my normal gear for training.

    Will have to wait until I’m stateside again to compare it to an MP5 and MPX.

    MP5s are pretty smooth. Some folks don't care much for them, but I've only shot one once, both semi and full auto. I had no complaints. :D

    Teratos and I have been playing around with adapting the RDB for a MP5 AR lower. Best of both worlds. The problem has been getting parts for the last couple years...
     

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    teratos

    My hair is amazing
    MDS Supporter
    Patriot Picket
    Jan 22, 2009
    59,775
    Bel Air
    MP5s are pretty smooth. Some folks don't care much for them, but I've only shot one once, both semi and full auto. I had no complaints. :D

    Teratos and I have been playing around with adapting the RDB for a MP5 AR lower. Best of both worlds. The problem has been getting parts for the last couple years...

    Yep. I STILL don’t have a lower. Probably should start looking again.

    This system would work, if we weren’t already invested in RDB.
    https://taccom3g.com/product/delayed-blowback-9mm-recoil-system/

    I may get one and try it WITH a RDB.
     

    erwos

    The Hebrew Hammer
    MDS Supporter
    Mar 25, 2009
    13,866
    Rockville, MD
    The Colt magazine is well proven though pricey. Brownell's sells an excellent alternative under their name and much less expensive.
    Look, I know this is a controversial statement, but of all the 9mm mag choices, Colt-style is the worst by far. A quality Glock lower is far better in terms of just being able to buy a factory mag and have a reasonable expectation it will function without extensive QC testing, never mind the whole magblock situation.

    If I were doing it all over again from scratch - and I might be, come to think of it - I'd go with either a proper CMMG MkGs RDB Glock mag receiver set, or I'd go with a standard lower and use Endomags (which I have mixed feelings about, but they clearly work well in an RDB setup). I would not go direct blowback again.
     

    erwos

    The Hebrew Hammer
    MDS Supporter
    Mar 25, 2009
    13,866
    Rockville, MD
    Yep. I STILL don’t have a lower. Probably should start looking again.

    This system would work, if we weren’t already invested in RDB.
    https://taccom3g.com/product/delayed-blowback-9mm-recoil-system/

    I may get one and try it WITH a RDB.
    It won't work with RDB, your gun will short strike, guaranteed. In fact, I bought one and it didn't even work with regular direct blowback. I think maybe it could work for some people, but I wasn't impressed.

    Some of the dudes on Brian Enos have started experimenting with this one, which is roller-delayed, and it sounds like it works better than you'd expect:
    http://scheelmfg.com/
     

    teratos

    My hair is amazing
    MDS Supporter
    Patriot Picket
    Jan 22, 2009
    59,775
    Bel Air
    It won't work with RDB, your gun will short strike, guaranteed. In fact, I bought one and it didn't even work with regular direct blowback. I think maybe it could work for some people, but I wasn't impressed.

    Some of the dudes on Brian Enos have started experimenting with this one, which is roller-delayed, and it sounds like it works better than you'd expect:
    http://scheelmfg.com/

    Alucard likes it. Maybe he’s in the minority.
     

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