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View Full Version : 11.5" AR-15, 9mm VS 5.56mm


nrakid88
12-19-2011, 12:34 PM
So, which would you choose, and WHY?

I personally gravitate towards the 9mm because i could load it with a hot 147 grain round (with a lot of slow powder, since I believe the sub gun magazines allow more overall length). With this combination, I think the gun would be quieter and have more penetration, not to mention being a bit cheaper than the 5.56.

As for the 5.56, I think it's main advantage is going to be range. I would most likely load it with 77 open tip match ammo, which would give it long legs, but it would suck balls at intermediate barriers.

Ultimately, these two guns would just be range toys... so I really am drawn to the fact that the 9mm AR-15 would be much quieter.

Insert you opinions, please.

Sturnovik
12-19-2011, 12:40 PM
So, which would you choose, and WHY?

I personally gravitate towards the 9mm because i could load it with a hot 147 grain round (with a lot of slow powder, since I believe the sub gun magazines allow more overall length). With this combination, I think the gun would be quieter and have more penetration, not to mention being a bit cheaper than the 5.56.

As for the 5.56, I think it's main advantage is going to be range. I would most likely load it with 77 open tip match ammo, which would give it long legs, but it would suck balls at intermediate barriers.

Ultimately, these two guns would just be range toys... so I really am drawn to the fact that the 9mm AR-15 would be much quieter.

Insert you opinions, please.

I always thought the 9mm AR's were neat. I could never afford to get one or a 5.56 for that matter, but it seems like the mags may be harder to find with the 9mm models? I think I read somewhere alot of makers are using the sten mags. Who knows.

nrakid88
12-19-2011, 12:45 PM
I always thought the 9mm AR's were neat. I could never afford to get one or a 5.56 for that matter, but it seems like the mags may be harder to find with the 9mm models? I think I read somewhere alot of makers are using the sten mags. Who knows.

I think that UZI mags are used in some... but I think the golden standard right now are metal form mags...

I can't really afford this thing either, and that is why I am going to start saving now. It's just easier to save when I know what all those untouched dollars are waiting for.

Jpach
12-19-2011, 12:51 PM
What kind of barriers are we talking about, and why do you need to shoot through them?

Nathan Krynn
12-19-2011, 12:56 PM
Ballisticly I think the .223 will beat the 9mm hands down.

Now I did not put into a ballistic calc but that is what you need to do.

nrakid88
12-19-2011, 1:01 PM
Ballisticly I think the .223 will beat the 9mm hands down.

Now I did not put into a ballistic calc but that is what you need to do.

I am sure the 5.56 will outperform the 9mm when the lead hits flesh, but I am confident in both.

The 9mm should do a little better than this http://www.youtube.com/watch?v=92j3g168dIY

And the 5.56 should do a LOT worse than this http://www.youtube.com/watch?v=55CkeT7qdtM

nrakid88
12-19-2011, 1:02 PM
What kind of barriers are we talking about, and why do you need to shoot through them?

Most likefully, I will need to shoot through your front door, to stop you from selling your bulgy 74.

But seriously, I think its more likely that i'd need to shoot through multiple interior walls of my house if I came against armed intruders.

Sturnovik
12-19-2011, 1:05 PM
Yea I know the 5.56 has way more energy, but I like the idea of being able to plink on a 9mm budget, and its sorta cool platform. Never new some used UZI mags. I remember someone talking builds and saying alot of the receivers can or do use STEN mags though. If I could find an AR 9mm or 5.56 for less than 700 bucks I'd jump right on the train.

C4iGrant
12-19-2011, 1:09 PM
So, which would you choose, and WHY?

I personally gravitate towards the 9mm because i could load it with a hot 147 grain round (with a lot of slow powder, since I believe the sub gun magazines allow more overall length). With this combination, I think the gun would be quieter and have more penetration, not to mention being a bit cheaper than the 5.56.

As for the 5.56, I think it's main advantage is going to be range. I would most likely load it with 77 open tip match ammo, which would give it long legs, but it would suck balls at intermediate barriers.

Ultimately, these two guns would just be range toys... so I really am drawn to the fact that the 9mm AR-15 would be much quieter.

Insert you opinions, please.

First let me say that I own both. From a pure defensive POV, the AR chambered in 5.56 wins. In regards to the 5.56 "sucking" at intermediate barriers, this depends on the ammo selected. If you use any of the quality LE loads (Federal T1 or T3, Speer GD or Hornady TAP Barrier), you will get very good results.

9mm AR's are fun and cheaper to shoot. They do not have the accuracy and range of the 5.56 though. They also tend to be less reliable.



C4

nrakid88
12-19-2011, 1:11 PM
Actually, I think the 9mm 11.5" ar would perform around this level http://www.youtube.com/watch?v=Q7w4M-LNXuQ&NR=1

nrakid88
12-19-2011, 1:17 PM
First let me say that I own both. From a pure defensive POV, the AR chambered in 5.56 wins. In regards to the 5.56 "sucking" at intermediate barriers, this depends on the ammo selected. If you use any of the quality LE loads (Federal T1 or T3, Speer GD or Hornady TAP Barrier), you will get very good results.

9mm AR's are fun and cheaper to shoot. They do not have the accuracy and range of the 5.56 though. They also tend to be less reliable.



C4

Good point, I could always load up some Barnes pure copper 70 grain triple shocks for the 5.56, I bet those would penetrate well, and they expand down to like 2100 or 2300 fps, but they don't fragment which is what I love about 5.56. And still, I have to deal with a lot of muzzle blast. In your experience, how bad is the noise level on short barreled 5.56 AR's?

And how unreliable are the 9mm ar's? Just last night I had a bad dream that I was having multiple malfunctions in a shooting gallery, which was pissing me off.

nrakid88
12-19-2011, 1:25 PM
Those barnes actually expand to 1800 fps

Here is a 55 gr triple shock from a 20 inch http://www.youtube.com/watch?v=2m2vaJCBQTs&feature=related

chead
12-19-2011, 1:27 PM
The 9mm will be very quiet. The quieter the longer your barrel is. To be honest, unless you can legit SBR it, I would go with a 14.5 and a pined brake. The idea of a 11.5 with a very long brake sketches me out for a 9mm. I'm sure it would be fine, but my concern would under-loaded 9mm yawing into the brake.

The unreliability is due mostly to non-adjustable magwell blocks as far as I can tell. If you build off a Double Diamond dedicated 9mm lower I doubt you'd have issues. Just look at the specs and mags carefully if you want a bolt hold-open. Mag blocks that use Uzi mags generally don't. On the other hand Uzi mags are dirt cheap.

C4iGrant
12-19-2011, 1:33 PM
Good point, I could always load up some Barnes pure copper 70 grain triple shocks for the 5.56, I bet those would penetrate well, and they expand down to like 2100 or 2300 fps, but they don't fragment which is what I love about 5.56. And still, I have to deal with a lot of muzzle blast. In your experience, how bad is the noise level on short barreled 5.56 AR's?

And how unreliable are the 9mm ar's? Just last night I had a bad dream that I was having multiple malfunctions in a shooting gallery, which was pissing me off.

The TSX bullets are similar to a bonded bullet, but NOT as good as the ones I listed for barriers.

SBR's are a EXTREMELY loud indoors. I have a 10.3 and have shot it in a lot of kill houses. It will blow your ear drums out. So this is why I would really thing about getting a suppressor for it.

The most reliable 9mm AR's I have seen are Colt's. I have a RRA that would run sometimes, but not others.



C4

nrakid88
12-19-2011, 1:34 PM
The 9mm will be very quiet. The quieter the longer your barrel is. To be honest, unless you can legit SBR it, I would go with a 14.5 and a pined brake. The idea of a 11.5 with a very long brake sketches me out for a 9mm. I'm sure it would be fine, but my concern would under-loaded 9mm yawing into the brake.

The unreliability is due mostly to non-adjustable magwell blocks as far as I can tell. If you build off a Double Diamond dedicated 9mm lower I doubt you'd have issues. Just look at the specs and mags carefully if you want a bolt hold-open. Mag blocks that use Uzi mags generally don't. On the other hand Uzi mags are dirt cheap.

I think i would go with a 16" barrel, and chop it to 11.5 when I can do so legally.

I need to check out the lower situation... but I am not a big fan of dedicated lowers. At that point, an MP5 seems even cooler.

chead
12-19-2011, 2:09 PM
I need to check out the lower situation... but I am not a big fan of dedicated lowers. At that point, an MP5 seems even cooler.

From most accounts, Hahn is the way to go for removable and semi-permanent: http://www.hahn-precision.com/AR-15_c11.htm

MrPlink
12-19-2011, 2:14 PM
I like 9mm SMG and PDW type firearms a lot, but that said I would stick to 5.56 for the AR.
More parts and options, easier to tune if you have issues, which is common with 9mm conversions.

Its too bad there arent more quality MP5 based carbines that are easily available/reasonably priced

chicoredneck
12-19-2011, 3:25 PM
The noise level on any short barreled rifle using ammo designed for rifle length barrels is defining. Even out of a 16" barrel 5.56 is much louder than it is out of a 20" barrel.

chicoredneck
12-19-2011, 3:26 PM
*deafening*

luchador768
12-20-2011, 10:22 AM
I try and keep my 11.5 AR pistols out of the local indoor ranges. My lane mates send me all kinds of dirty looks. The Noveske KX brakes are supposed to help with muzze blast, but I've never tried one.

Nathan Krynn
12-20-2011, 1:42 PM
I try and keep my 11.5 AR pistols out of the local indoor ranges. My lane mates send me all kinds of dirty looks. The Noveske KX brakes are supposed to help with muzze blast, but I've never tried one.

The Noveske just focuses it forward. It is named the flaming pig for a reason.

Now the CQB comp from PWS really takes out most if not all of the muzzle blast.

nrakid88
12-20-2011, 5:20 PM
The TSX bullets are similar to a bonded bullet, but NOT as good as the ones I listed for barriers.

SBR's are a EXTREMELY loud indoors. I have a 10.3 and have shot it in a lot of kill houses. It will blow your ear drums out. So this is why I would really thing about getting a suppressor for it.

The most reliable 9mm AR's I have seen are Colt's. I have a RRA that would run sometimes, but not others.



C4

Too bad Hornady doesn't sell that 62 SP as a component.

And yes, I would get a suprressor (more like five) in a heartbeat, if I could.