Why 9mm?

[Shiz]

I have noticed that 9mm is becoming a more and more popular cal. for AR carbean, pistol/SBR.

Wondering why.

-low cost ammo?
-easily suppressed?
-market driven? more available, price is right?
-fun range gun that you can shoot steel with at short ranges?

Not saying your decision is wrong or right, just wondering the rationale.

Also, would you ever grab this as a home defense weapon? If so, why?

[Voodoo_Man]

There are a couple of threads on this so I won't post a thesis just some points.

- modern defensive ammo is tested to the same standards so 9mm peforms just as well as other, larger, calibers
- accuracy is more important than caliber, if you are more accurate and able to put rounds on target faster with a certain caliber, then you should use that caliber.
- glock 9mm pistols are awesome
- 9mm is extremely cheap compared to 40 and 45
- pistol ammo is ineffective at stopping people, so you should be fighting with your pistol to get to your rifle
- the more ammo you have the longer you are in the fight (and possibly increase your hit percentage) - I carry a spare g17 mag with a taran end plate that gives me 20+ rounds, not many calibers can do that.

There is more and tons of science behind it, but thats the gist.

[fixit69]

I've only played with a friends ar pistol in 9mm a couple of times. What I see is a fun toy with possibilities. A brace, a red dot and I think a more familiar mp5.

And little recoil helps accuracy. And did i say fun? It may be in my future...

[Hmac]

Cost and availability. 9mm is the sweet spot relative to ballistic performance and recoil/flash/cost.

[Cheyenne]

I had decided to go the AR pistol route and use the Sig brace for a basic SBR build with out having to get permission to build or travel with. A short rifle just makes sense in an Urban setting, either in a vehicle or house.......also wanted this quasi SBR to be the house gun......I kept putting it off and the reason was the obnoxious blast a 5.56 makes....especially in a HD situation, where you will likely not have grabbed a set of muffs.

Another thought was my wife and older son would also have access to it for HD.....lower recoil and blast.....they both can shoot the 9MM with confidence.

With a 10" barrel, and quality +P hp ammo, this little gun is approaching 357 mag ballistics, and that is nothing to sneeze at.

You tube has some interesting videos titled how far will a 9mm kill.....with fmj the rounds fully penetrated a 1/2 plywood board and sometimes also the 2X4 frame out to 440 yards! A second video they used Federal HST 124gr......using ballistic gel at 440 yards, the rounds still expanded....now granted, shooting a 9mm carbine at that distance is hit or miss, but it can be done and would still be lethal....

So, while I have a couple 5.56 carbines in the safe, and a couple more in process of building, I also have a 2nd 9mm in the works! I'll be a much shorter one with the Law Tactical folder attachment to make it even lower profile. Receiver is the BCP slim 9mm receiver using Colt magazines.....my first is a QCT Glock lower.

[DWood]

Because a 147 grain round from my 4.5" Adco barrel with a suppressor remains subsonic. At least it will once I finish the lower.

[750.356]

-fun range gun that you can shoot steel with at short ranges?


This is my primary use. I have an excellent private range with tons of pistol rated steel, plate racks, and poppers, and can do whatever I want here with a Colt 6951. In this capacity, it's more than just 'fun range gun', and becomes a valid training tool, IMO. Recoil is similar to a 5.56 AR (could be harder, could be softer, depending on the 5.56 gun's setup), so it's much more valuable for doing target transitions and 'fast' drills than a .22lr upper.



-low cost ammo?


Not a primary motivator, but nice to have. For any given ammo budget, one can shoot more quality 9mm than they can quality 5.56.



Also, would you ever grab this as a home defense weapon? If so, why?


Maybe. I'm certainly not opposed to it. While I concede that a 5.56 gun is much more versatile and effective, a part of me can't get past the idea of lighting off a 10-14.5" 5.56 gun indoors, unsuppressed. Despite my understanding of the very elegant protective mechanisms that the body uses in the middle ear for hearing protection in a fight... I just can't get past it.

I'm very protective of my hearing though, and have always been the type to wear protection even on lawnmowers, etc. In states where cans are prohibited, this is a big drawback of a 5.56 gun, IMO.

Generally, my 'go-to' beside gun is a handgun for mobility/ ease of one-handed use reasons, but I don't think I'd scoff at a 9mm AR for HD purposes. Someone that has a good level of familiarity with a properly set-up 9mm AR can easily put lots of rounds on a small target at across-the-room distances with some extremely fast split times. Couple this with the fact that good +P defensive 9mm rounds are exiting the muzzle with .357 magnum velocities with this level of control and precision. When compared with a handgun, they are also much, much more shootable if you need to make fast, reliable hits at 25-100 yards.

Of course, you're still tied to pistol-level ballistics in a 6-7 pound carbine package.

With where I'm at right now, a 9mm AR is not my first choice, but definitely not a choice I immediately overlook as 'inadequate' for HD.

[GeorgeB]

A handgun round is still a handgun round at the end of the day, with all the ballistic disadvantages of a handgun round.

[NCPatrolAR]

http://i176.photobucket.com/albums/w167/DefConNC/forum%20pictures/592100D9-4BC6-4E1F-B1B0-AC92155DE392_zpsxz8zetir.jpg (http://s176.photobucket.com/user/DefConNC/media/forum%20pictures/592100D9-4BC6-4E1F-B1B0-AC92155DE392_zpsxz8zetir.jpg.html)

I went with a 9mm since most shoot houses don't require frang pistol ammo and my AR pistol is mainly for working in houses

[evnash]

building mine cause i can reload 9mm for around $.11 each. not set up for .223 and if you factory in the cost of your time you really dont save much on reloading .223

[HeavyDuty]

I built mine in 2004 to have something I could shoot at commercial indoor pistol ranges during our long, cold winters. It's been a lot of fun, to the point I'm considering building a 9mm AR pistol for a range toy.

[Cheyenne]

A handgun round is still a handgun round at the end of the day, with all the ballistic disadvantages of a handgun round.

However, if the handgun cartridge is running out a 10" barrel, it does pick up some steam. Might be interesting to compare 9mm directly with 223 in the short barrels, say 7".

[U&A]

I have one for a truck gun/HD gun.

for Home Defense: it is not my only HD gun option as I also have my 12g out when I am home. I don't go for a rifle for HD only because of were I am located. I have other houses very close in all directions so that is a little bit of a concern for me but it isn't the main reason that I have a 9mmAR for HD.

MY reasons to have a "9MM" AR (to each his own)

1) over penetration of rifle calibers is a little bit of a concern for my home location
2) My little wife has a hard time with the size and recoil of a standard AR or AK.
3) because of #2 My wife will train with it making it a good choice for her as well
4) muzzle blast is significantly lower when shooting indoors
5) 9mm has proven itself to be a "decent" SD round if you get the right stuff. (mine is full of high quality +P BJHP's) and you cant argue with the higher velocities and energy from the longer barrel. the 9mm out of a 8" barrel is similar to a .357mag coming out of a snubby or even a 3"-4" revolver.
6) if the MP5 and clones are so good than why cant a 9mm AR be good. (I know, only close range scenarios)
7) If you really want to get serious, (very unlikely to need it but) the ammo is interchangeable with my carry gun....and my wife's carry gun......and my moms.....and dads.
8) ammo is cheaper than 556 so I will shoot it more often than am others....accept my AK.. ammo is the same price for them (9mm and 7.62x39).
9) lower recoil = faster follow-up shots....(9mm-ar has significant recoil because of the heavier bullet and heavier buffer but I think it is generally still less than a 556)
10) its cool :cool: lets face it...if we can buy a Mustang or Camaro because it looks cool and can do cool things than why cant I but a gun because it looks cool and can do cool things. I have nothing against someone trying to "tacticool" their stuff out as long as its not excessive to the point of ruining or slowing down function.
11) Iv always wanted a 9mm sub gun and this is as clos as I will get.


with the SIG Brace it is very handy

[markm]

The 9mm AR was something I wanted until I shot a few. The blow back recoil with the heavy buffers make it a ridiculous idea in my opinion. If I'm going to shoot a round that weak, it'd damn well better shoot fast and smooth. Not the case with any ARs in 9mm that I've shot.