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Posted: 8/27/2004 6:16:30 AM EST
I have read a considerable amount about ballistics from the AR/M16/M4 but have found little information on SBR's. What recommendations for bullet type and weight when shooting from a 1:7 10.5" barrel? Obviously I am not looking for accuracy on paper but rather bullet performance on flesh.
Link Posted: 8/27/2004 6:28:47 AM EST


Hornady 75gr TAP

Even with the heavier bullet (75gr) and lower fragmentation threshold (approx. 2300 fps) you'll be lucky to reach that velocity at the muzzle.

10.5" barrels certainly have a cool factor, but are generally poor performers against real threats.

Link Posted: 8/27/2004 7:08:28 AM EST

Think Ruger 10/22 .22LR
Link Posted: 8/27/2004 7:18:52 AM EST
Link Posted: 8/27/2004 9:03:52 AM EST
75 gr. TAP rounds will reliably fragment out to 50 yards from a 10.5" barrel
Link Posted: 8/27/2004 11:12:49 AM EST
Yes.
I wanna see real world results from a 10.5-11.5" barrel.
Using USGI ammo.

Inside 50yrds.
Link Posted: 8/27/2004 11:19:49 AM EST
Link Posted: 8/27/2004 11:23:33 AM EST
Link Posted: 8/27/2004 11:25:44 AM EST
[Last Edit: 8/27/2004 11:26:03 AM EST by SHIVAN]
Link Posted: 8/27/2004 11:39:32 AM EST

It's a .22LR that can penetrate vests. It's the duplicate of the FN 5.7mm, except when Mk262 type ammo is used. Okay, okay, it's a very very strong .22LR.
Link Posted: 8/27/2004 11:46:16 AM EST
Link Posted: 8/27/2004 11:54:04 AM EST
So why do we see so many 10-11.5 uppers over in the sandbox?

If it can't get M193/M855 up to speed, what's the point?

I know about the space saving approach, but what else?

Am I missing something?
Link Posted: 8/27/2004 11:56:55 AM EST
Link Posted: 8/27/2004 11:58:57 AM EST
Link Posted: 8/27/2004 12:04:50 PM EST

Originally Posted By Lumpy196:
heres one we havent done in a couple of days...


You see them in the sandbox used by private security who spend most of their time in SUVs.





Lumpy,
Just tell yourself "TGIF".
You'll feel better.



Link Posted: 8/27/2004 12:18:38 PM EST
Link Posted: 8/27/2004 12:21:23 PM EST
Alright.
That sounds good.
I can digest that.
Link Posted: 8/27/2004 1:01:39 PM EST
Back in ye olde days of ar15.com, An employee of Crane NSWC used to post here and addressed this issue (this was years ago). He stated quite simply that these uppers were destined for the hands of highly trained operators for use at across-the-room distances i.e. "all CNS shots" (his quote). The 10.5" upper has obviously gained more widespread use since then.

He also stated that M855 would fragment reliably out of a 10.5" barrel. As co-author with Dr. Fackler of a paper on M855 fragmentation in ballistic gellatin, he probably had some basis for that claim.
Link Posted: 8/29/2004 2:14:17 PM EST
Thanks for all your input. I agree many times the "cool factor" outweighs the performance from such a short barrel. Does anyone have links to data, after actions reports from shootings? I am trying to maximize the 5.56 performance from this short barrel but would like to read facts rather than speculations.
Link Posted: 8/29/2004 4:59:59 PM EST
As with anything, it has its limitations. If you know those limitations and stick to them, you will be fine. Some contractors know what they are doing and will use a short barrel where it is most appropriate, and some don't. In military circles, the CQBR is used just for that, CQB. It is for hunting in caves and buildings mostly. Shooting out of a vhicle is fine as long as the target is only a few meters from your window. In most urban environments, it will suffice. Anyway, ideally, it would only be used for fighting your way out of your vehicle and toward a place where a longer range weapon can be used more comfortably, (stating once again) ideally.
Link Posted: 8/29/2004 5:36:09 PM EST

Seems to me that a sub-machinegun, perhaps shooting AP rounds, would be a better choice for shooting out a car window just before you exit.

Lumpy196 posted a picture of an Israeli soldier a few weeks ago carrying both an M4 and one of the shorty’s you describe. Perhaps the Israeli army is the only organization with extensive experience with them.
Link Posted: 8/29/2004 5:41:06 PM EST
Link Posted: 8/29/2004 5:44:46 PM EST
[Last Edit: 8/29/2004 5:46:25 PM EST by knightone]

Originally Posted By Robert2011:
Seems to me that a sub-machinegun, perhaps shooting AP rounds, would be a better choice for shooting out a car window just before you exit.



5.56mm still has far superior ballistics to any handgun ammo, even from a short barrel, if it is used at the appropriate ranges. Having stuff like Mk 262 ammo helps a whole lot in that regard.
Link Posted: 8/29/2004 6:09:41 PM EST

Link Posted: 8/29/2004 6:16:59 PM EST

I never had a problem with 20" barrels myself, but I was in a Hummer, not an SUV like some of these private contractors. Did you know they issue M1 tanks a 20" M16? Try and get that out a turret quick.

I read about some HMMWV drivers keeping sub-guns on their laps so they could spray the roadside. They were not intent on dismounting though, just driving by with no hands on the wheel.
Link Posted: 8/29/2004 10:21:02 PM EST
Link Posted: 8/30/2004 6:18:01 AM EST
As for barrel length in the sandbox, apparetnly lots of folks over there (light infantry, not contractors) have picked up surplus Beretta M12 and Sterling SMGs for use in the vehicles and only use their M-4s when they dismount. Those units who have access to MP-5s are using them in this role as well.
Link Posted: 8/30/2004 9:15:55 AM EST

I think this is the Israeli gun I saw:
Link Posted: 8/30/2004 1:01:49 PM EST

Originally Posted By Robert2011:
I think this is the Israeli gun I saw:
pic4.picturetrail.com/VOL715/2561825/5090639/65251536.jpg



That looks like a 7.5" barrel, which would be practically useless no matter what ammo you used at any range. I've never sen an Israeli carrying anything less than 11.5", but anything is possible I guess.
Link Posted: 8/30/2004 1:07:20 PM EST

I found some more chopped ones here:
www.isayeret.com/weapons/assault/car15/car15sawn.htm


The coolest looking one I've seen is a 9mm:
Link Posted: 8/30/2004 1:40:03 PM EST
Link Posted: 8/30/2004 1:44:44 PM EST

Now I'm confused

Pat Rogers is talking about 10.5s over on TF.

He says:
"This is the best AR that i have ever used- ever.
I would take this to a fight at any time."

Somebody please tell me I'm wrong about this. And hurry!

It's in the Seal forum.
Link Posted: 8/30/2004 2:01:37 PM EST
I have been looking into the same data and the conclusion I have come to is to get the best possible effect from a 10.5 barrel you need to go to soft point ammo such as the 62gr power points.
Good luck with your shorty.
Link Posted: 8/30/2004 2:04:11 PM EST

Here is what he says:

"...Black Hills with the MK262 Mod 1. It is not a death ray, but is sufficient for the distances at which this bbl. will -or should- be used at.

The 10.5" bbl is- like all things- a compromise.
It makes perfect sense while mounted or doing VBSS/ GOPLAT's and PSD's.
The 14.5" barrel is a better- much better- general purpose length.
The advantage of the MRP is- besides efficiency- the one minute barrel change, which gives a Shooter another option.
Right tool for the right job."
Link Posted: 8/30/2004 2:30:56 PM EST
Link Posted: 8/30/2004 2:37:20 PM EST
Link Posted: 8/30/2004 3:04:15 PM EST

Originally Posted By knightone:
As with anything, it has its limitations. If you know those limitations and stick to them, you will be fine. Some contractors know what they are doing and will use a short barrel where it is most appropriate, and some don't. In military circles, the CQBR is used just for that, CQB. It is for hunting in caves and buildings mostly. Shooting out of a vhicle is fine as long as the target is only a few meters from your window. In most urban environments, it will suffice. Anyway, ideally, it would only be used for fighting your way out of your vehicle and toward a place where a longer range weapon can be used more comfortably, (stating once again) ideally.



It seems to me that when shooting at people some distance from your vehicle, rapid & total incapacitation may not be all that necessary. Even "10/22" wounds might convince them to go elsewhere, or at least convince them not to pile into their white Toyota P/U and follow you . . .
Link Posted: 8/30/2004 4:23:29 PM EST
[Last Edit: 8/30/2004 4:25:02 PM EST by Robert2011]

Originally Posted By Lumpy196:
[Whats confusing about this Robert?




That was on page two, which I hadn't read when I posted.

edited to add: Lumpy don't kill me !
Link Posted: 8/30/2004 5:37:34 PM EST

Originally Posted By DonS:
It seems to me that when shooting at people some distance from your vehicle, rapid & total incapacitation may not be all that necessary. Even "10/22" wounds might convince them to go elsewhere, or at least convince them not to pile into their white Toyota P/U and follow you . . .



Um...okay.
Link Posted: 8/30/2004 6:20:02 PM EST
Link Posted: 8/30/2004 6:53:30 PM EST

I can accept Mk262 ammo changing the 10.5” barrel into a nice short range piece for clearing out a parkingspace for the SUV, but, "This is the best AR that i have ever used- ever” ?

Then he says, “The 14.5" barrel is a better- much better- general purpose length.”

= my confusion…

Troy helped clear it up by saying, “Clearly, his comment wasn't directed at 10.5" barrels, but at the MRP system in general.”

That makes sense now, I think
Link Posted: 8/30/2004 10:51:19 PM EST
Link Posted: 8/31/2004 2:50:48 AM EST

Originally Posted By Robert2011:
Now I'm confused He"This is the best AR that i have ever used- ever.
I would take this to a fight at any time." hock.gif

Somebody please tell me I'm wrong about this. And hurry!

It's in the Seal forum.



Link?
Link Posted: 8/31/2004 5:34:42 AM EST
I'll IM it to ya.
Link Posted: 9/9/2004 10:32:12 AM EST
[Last Edit: 9/9/2004 10:34:37 AM EST by Robert2011]
The Oct/Nov issue of SWAT has an article on the LMT MRP system where Pat Rogers says the 10.5" barrel, "...offers some great advantages for certain missions...the shorter barrel makes for a much handier weapon. In this case, the ease with which the carbine can be deployed may mean the difference between winning and losing."

He goes on to say you better be ready to deliver multiple rounds into your opponent and MK262 is the round preferred.

This thread has been a learning experience.
Link Posted: 9/9/2004 6:31:44 PM EST
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