9mm AR pistol ideas

[graycrait]

In my never ending quest for the weird and whacky a fella said he would make me a good deal on a 9mm RRA AR pistol.

I was wondering if any other forum members had such a beast and might give me pointers as to what makes sense and what doesn't as far as optics or other tinker toy AR pistol "doo dads." I think I am going to get it but there isn't any hurry.

Craig in Clarksville

[Patton]

An old Army buddy of mine was telling me about his and I couldn't quite grasp the concept of why one would want one. I think about the usefullness of one vs a Glock with a 33rd mag. It seems a 5.56 round will slice through a lot more than a 9mm would. I would love for someone to bring up a good reason for it though.

[Guest Lester Weevils]

I'm having a similar failure to see any benefit. Can see possible benefit of a 9mm AR rifle, especially if SBR. There is marginal utility of a .223 AR Pistol. But what benefit is a giant heavy 9mm pistol that can't do anything an ordinary 9mm pistol can't do?

Maybe just hunt down a 7 or 8 inch barrel for a glock 17 or beretta 92 and call it a day?

Edited July 3, 2011 by Lester Weevils

[Westwindmike]

What they both said!!!

[Mr. Brooks]

Some SWAT teams use SBR 9MM AR's for room clearing. 5.56 will often over penetrate, hitting friendlies on the other side of a wall. Sounds like a pretty good use to me.

Think of a 9MM AR as a sub gun (MP-5 or similar) with the benefits of having the same manual of arms many people are already used to.

As far as what to hang off of it, I would toss a small red dot like a Burris fastfire on it, then get a one point sling. Push the weapon out in front of you putting tension on the sling to stabilize your aim when you fire.

[Guest Lester Weevils]

Some SWAT teams use SBR 9MM AR's for room clearing. 5.56 will often over penetrate, hitting friendlies on the other side of a wall. Sounds like a pretty good use to me.

Think of a 9MM AR as a sub gun (MP-5 or similar) with the benefits of having the same manual of arms many people are already used to.

As far as what to hang off of it, I would toss a small red dot like a Burris fastfire on it, then get a one point sling. Push the weapon out in front of you putting tension on the sling to stabilize your aim when you fire.

I agree Mr. Brooks. An SBR 9mm AR could be pretty kewl. But a 9mm AR pistol is not an SBR. SBR's are pretty easy to aim and maneuver. Giant pistols the size of an SBR are pretty difficut to conventionally aim and maneuver. Even with a 1 point sling for stability.

It is just a giant heavy 9mm pistol that can't do anything that an ordinary-sized 9mm pistol can't do? Am not being argumentative, because I'm pretty sure you know a whole lot more than I do on these topics. Just curious.

[Dolomite_supafly]

My wife has a 9mm AR that has over 7,000 rounds through it now and here is my take on them.

I built her a 9mm and she loves it, as do most people who shoot it. The reason is because there is very little muzzle blast compared to a 5.56 gun. She isn't recoil sensitive but very blast sensitive so the 5.56 I built her initially was out rather quickly. Believe it or not but a 9mm blow back AR has more of a recoil impulse than a 5.56 gas gun. I have shown dozens of people the comparison and most people don't believe it until they shoot both.

Another advantage of a 9mm AR over a 5.56 AR is inside enclosures like a car or in your house. Touching off a 5.56 in a car or even inside of the house can be very disorienting even with hearing protectionon . Without it and it will extend any chance of a follow up shot for a second or two. 9mm is much more forgiving inside especially when you start getting into the shorter barrel lengths. If I had to have a AR with a short barrel (under 9.5") I would choose a pistol caliber.

Dolomite

[Dolomite_supafly]

And one more thing. The extra barrel length will add velocity to the bullet and additional velocity is generally a good thing.

Even if it is in pistol configuration it is still easy to shoot accurately. Put the buffer tube on top of your shoulder, your check on the tube to get a decent weld and it is as accurate as you need to be with a short barrel.

Dolomite

[Patton]

Im not so sure that with a 9mm your not getting 95% of max veloicity out of a 4.5-5" barrel. I say that because I believe it has been brought up before.

[Patton]

Optimal 9mm AR barrel length? - M4Carbine.net Forums lighter bullet would need the longer barrel I understand. Ammo manufacturers/size may be different.

[graycrait]

on the AR 9mm the buffer tube acts as sort of a stock. One guy I know dished out a hocky puck, put Velrco on the back and used it as sort of a shooting pad. I'm not sure if one even needs padding if you placed the tube in your shoulder socket. With a 10.5" barrel it seems more a hybrid SBR/pistol with the legal status of a pistol.

Rock River Arms: RRA LAR-9 Pistols / 9mm

[Guest Roadkill Bill]

Yet another answer in search of a question.

[Guest Lester Weevils]

Thanks Dolomite and Graycait for the concept using the buffer tube as ersatz stock.

Hadn't seriously considered getting an AR pistol with a buffer tube, in any caliber, because the buffer tube looked more useless than teats on a boar hog.

Wonder how fat the buffer tube padding could be without ATF deciding that it is an SBR and not a pistol? Am ignorant of NFA and ATF, but a hockey-puck sized pad might be pushing the boundaries? One could explain that a big pad is to make the buffer tube bigger than an eyesocket and prevent accidentally stabbing oneself in the eye. Dunno if ATF would be impressed with such an explanation if the user routinely shoots the pistol using a rifle stance?

[graycrait]

the fella that used the hockey puck had it velcroed to his shoulder. I'm wondering why with a 9mm would a pad even be necessary?

[graycrait]

although not so significant unless the barrel is at least carbine length: BBTI - 9mm Luger

[Guest Lester Weevils]

the fella that used the hockey puck had it velcroed to his shoulder. I'm wondering why with a 9mm would a pad even be necessary?

Thanks Graycait

I dunno much about it and am just thinking/wondering, rather than prove any point. Trying to learn something.

It sounds like a fabulous idea to use a buffer tube as an ersatz stock.

I don't think padding would be necessary for a 9mm. Even my PLR-16 in .223 has less felt recoil than a .357 Mag.

But every time I've looked at AR pistols with the buffer tube, have thought, "That would do damage if you managed to stick that in yer eye." I'd want a pad significantly bigger than an eye socket just for safety. So that a klutzy accident would be more likely to make a black eye rather than serious eye damage. It would be life-changing if you accidentally fall down and get the skinny buffer tube in the eye.

It wouldn't be a very good day to accidentally fall down on that buffer tube somewhere on the chest or abdomen either. People have died from accidentally falling on broom sticks or toilet plunger sticks, which are about the same diameter. It is doubtful that any of those people intentionally fell on the sticks.

Some of the AR pistols with buffer tubes look like the designer intentionally tried to make the tube as short as possible. Some of them are not much more than nubs.

But if desiring to use it as an ersatz stock then the longer the better, within reason?

Edited July 5, 2011 by Lester Weevils

[graycrait]

It is not that I have a practical use for the AR 9mm pistol or any AR pistol for that matter. In my lifestyle I don't have a use for any AR, and have sold off or traded all my zombie killers. It was just that I was talking to a guy who has more AR and tactical rifle's/carbines than I have fingers and toes and brought up the question of the practicality of an AR 9mm Carbine, which this guy has several. Then the discussion drifted to AR pistols. Then it drifted to the fact that this guy has 3 AR 9mm pistols and mentioned he would sell one. This may be a case were outside opinion may save me from myself cause I am beginning to get the feeling that a 9mm AR pistol would last less time in my possession than many of my other nonsensical gun notions.

[Patton]

If i were set up to reload 9mm and not 5.56 I would go for the 9mm, especially if the initial purchas price was close to the same.

[Dolomite_supafly]

A 9mm blowback has more felt recoil than a 5.56 gas gun. I have over 7,000 rounds through my wife's 9mm AR and well above that through various 5.56 AR's. None of the 5.56 AR's recoil as hard as the 9mm or at least not the ones with flash hiders or muzzle brakes. Dolomite

[Guest Lester Weevils]

Thanks Dolomite, that is interesting.

My Beretta Storm 9mm rifle is perhaps a little lighter-weight than the STG 556. The Storm recoil is either lighter or about the same as the STG 556. The PLR-16 5.56 pistol feels like it has less recoil than either.

However none of them have enough recoil to be bothersome.

The Storm has a big blowback bolt, which may minimize recoil? Dunno. The PLR-16 is piston-operated, but dunno if that would reduce the recoil.

Anyway, none of them are AR designs so it is apples to oranges comparison. Just an interesting topic.

If big heavy blowback bolts tend to recoil less, then maybe there isn't enough room in an AR design for a big enough bolt? The bolt in the Storm rifle takes up a lot of space.

I have a little blowback .380 pistol that has nasty-unpleasant recoil for its size.

Are all the 9mm AR's blowback operated?

Almost bought a Spikes 9mm AR carbine one time. It looked really nice. Maybe should have got that rather than the Beretta Storm, but the Spikes had quite a bigger price tag.

Edited July 6, 2011 by Lester Weevils

[Dolomite_supafly]

There are several custom builders that are making several pistol caliber AR's that are gas driven. From memory they make them in 7.62x25, 9mm, 10mm and 45 ACP. I do know they require a gas tube that is way shorter than even a pistol length gas tube. Of the non standard DI builds I have built I have done a 7.62x25 but never got it to run 100% so I had it chambered it in 7.62x39. After that it was 100% reliable with factory ammo as well as using my 180 grain loads.

I do know from discussions that gas driven pistol caliber AR's have very little recoil, compared to blowback guns, because the it soaks up a lot of the recoil. It is also very tunable to increase reliability and decrease felt recoil. It also makes for a cleaner system than blowback whether using a DI or piston setup.

Here are some discussions on gas driven pistol caliber AR's:

http://www.ar15.com/forums/topic.html?b=3&f=15&t=366336&page=6

http://www.ar15.com/archive/topic.html?b=3&f=15&t=509364

Here is one of the more prolific custombuilders:

http://www.teppojutsu.com/

Ron Williams is another builder that does an equally good job building custom AR's. I do believe this is his 7.62x25 DI AR:

http://www.cncgunsparts.com/ar-15_m-16_762x25_uppers

I have had more positive dealings with Ron than with Teppujitsu. I asked Teppu if his system would work with subsonic 7.62x25 rounds and his response was "buy one and find out". A few other general questions resulted in similar responses.

I have provided Ron, through a mutual friend, with some of my subsonic load data I worked up. He has also provided me with some data as well, again through a mutual friend. I also worked on what twist rates where needed to get a subsonic bullets to tumble in the 7.62x25. I did this for a friend of both Ron's and I's.

I also have a 9mm blowback I built from a parts kit. Nothing out of the ordinary and anyone could have put it together. It uses a standard 5.56 carbine buffer and is 100% reliable with everything except a few HP styles.

I have done several blowback 7.62x25 AR's for myself. I didn't like them because they were loud, noisy and actually painful if you did a lot of shooting. After a few hundred rounds I would have bruising because the gun only weighed around 5 pounds and had quite a recoil impulse. Ultimately I gave up on the 7.62x25 AR's and built bolt guns because I was more interested in shooting subsonic rounds but still wanted the ability to shoot surplus.

Dolomite