PDA

View Full Version : 223 ammo outta short AR-15/16


Mail Clerk
05-17-2010, 6:19 PM
Hello to all,

This question is for you AR-15 gurus.

I was reading my latest issue of Guns and Weapons and noticed an advertisement for Robinson Arms which had a 9" barreled sub-machine guns type of rifle. It gave me the thought of why would anyone need a short barreled AR style rifle???? They even offered it in the 223 nato round.

Isn't these designed for CQB usage???? and so if they are would the short barrel stableize the 223 bullet?????

Compared to my 16" barreled AR's I feel these would be completly useless as any type of service rifle in the field cuz it wouldn't give any good groups past 100 yards.

If you guys feel different what amount of yards would this be useful???? Perhaps nothing more than 50 yards??? I highly doughbt 100 yards using 55 grains bullets.

Just curious...... Let me know what you think.

Mail Clerk

Rob454
05-17-2010, 7:01 PM
If I understand this correctly the short barrel AR uppers can only be used on lowers specifically marked as PISTOL lowers. There are SPECIFIC rules you must follow when building a pistol AR. I dont know the rules.

Noobert
05-17-2010, 7:03 PM
Or have a really long extension, but the short barrel will hold the 223 back since it doesn't have the same velocity

ElvenSoul
05-17-2010, 7:09 PM
Just search Calguns for AR Pistols...there is like a million threads.

sd1023x
05-17-2010, 7:16 PM
I remember seeing a video where a SF guy shoots two 'warning shots' at a truck with a 10" suppressed AR in Afganistan, I couldn't really judge the distance, but I would postulate less than 200 yards (probably less). He shot two kids, one grazed (made a nasty looking crease) and the other in the chest. Kid in the chest was crying and literally going "WTF!"

Sometimes you need more gun.

Mail Clerk
05-17-2010, 7:17 PM
Hi guys,

I don't plan to ever buy an short barreled AR since it's illegal in California. I feel lucky I can have any AR-15 even if it has the "bullet button" installed.

I was just curious due to the magazine advertisment I saw in my gun magazine.

Mail Clerk

cmace22
05-17-2010, 7:34 PM
Short barreled anything has its place. If you want a compact package for getting in and out of vehicles, concealment, door kicking, an SBR is the way to go. In regards to your 556/223 question AFAIK the effective range is greatly reduced when using an SBR. Thats not to say accuracy is effected but more of shortening the fragmentation range of the round. As I understand it the call to fame of the round is its fragmenting ability and relies primarily on it reaching a specific velocity. I believe its 2700fps. I think there are some specialty rounds that may not rely on fragmentation but M193 and m855 do.

When you get into SBR's there velocity falls off quick style. Thats why many say the 6.8 is superior to the 556 inside of 300 yards especially out of short barrels.

I hope this helps.

sd1023x
05-17-2010, 7:57 PM
It does have its place, I wouldn't want to be shot with it, period. If your shot, without professional medical care, its gonna get nasty real fast (even if its 'just a flesh wound', without antibiotics your chances of survival get medieval).

But, I would say, it address a certain need. Its a CQB gun that is great at defeating soft armor targets, but doesn't possess super take-down capabilities. Would that be fair?

todd2968
05-17-2010, 8:05 PM
Pistol my PLR-16 .223 has an 18" overall length

Mail Clerk
05-18-2010, 6:01 AM
cmace22 and sd1023x,

I understand that because of a short barrel the 223 nato velocities would be greatly reduced but I wonder about it's accuracy at let's say 100 yards????

The typical foot soldier or police SWAT member using such a weapon is strictly designed for close quarters engagement only and nothing else because of the short barrel.

If that's the case then why don't these specialized people just use a 9mm sub machine gun????? Wouldn't the 9 be better than a short barreled 223??

Mail Clerk

technique
05-18-2010, 7:17 AM
Dude...

There are guys out there that can put WHATEVER they like in a conex box for their trips over seas...

I know of guys who CHOOSE to bring 7.5in. ARs over 10.5in ARs.

They are light, maneuverable, and a 7.in barreled gun is better than no gun or a larger gun where moving in and out of hallways/rooms, vehicles, or standing around at a checkpoint becomes cumbersome.


Step out in front of a SBR, tell me how that works out for you!;)

xibunkrlilkidsx
05-18-2010, 7:22 AM
mmmm....that would look awesome with a fake can in Ca.

pacrimguru
05-18-2010, 7:28 AM
It gave me the thought of why would anyone need a short barreled AR style rifle????

it's funny how guys are so concerned about small tight groups at range and "effective" velocity when talking about SBR length AR's. the entire point of an SBR is maneuverability, concealment, and weight. when kicking doors down, many engagements are measured in feet not yards. remember, SBR's aren't for bench shooting.

1988
05-18-2010, 8:36 AM
If you know that you'd only engage targets at 30-yd range or less, then why bring a longer and heavier barrel ?

On soft targets at 30-yd range, a SBR with good selection of ammo is as effective as other longer barrels.

sd1023x
05-18-2010, 9:44 AM
cmace22 and sd1023x,

I understand that because of a short barrel the 223 nato velocities would be greatly reduced but I wonder about it's accuracy at let's say 100 yards????

The typical foot soldier or police SWAT member using such a weapon is strictly designed for close quarters engagement only and nothing else because of the short barrel.

If that's the case then why don't these specialized people just use a 9mm sub machine gun????? Wouldn't the 9 be better than a short barreled 223??

Mail Clerk

9mm/45acp won't penetrate soft armor at almost any range. Thus you see the move of Personal Defense Weapons (PDWs) to close that gap. You have new round like the FN 5.7 designed for SMG sized weapons able to penetrate soft armor. But why reinvent the wheel? A LWRC PSD SBR will do the same thing.

Now on a unarmored target, would .45ACP/9mm SMG be the best choice for a CQB weapon? I would say no, the best would be 10mm SMG! j/k yes

Accuracy....barring some weights and lengths of ammunition, I would say, its not a 1moa gun, but plenty combat accurate.

slagusmc
05-18-2010, 12:00 PM
My buddies in Force Recon are using 10.5 in M-4s right now, and they are very happy with them. My buddy says he is hitting man-size targets are 400 yrds consistently..With training comes profiency..

slagusmc
05-18-2010, 12:01 PM
Oh and the other "SF" guy that engaged the vehicle and shot the kids by mistake was army...enough said,lol. Hoorah!!

Mail Clerk
05-18-2010, 12:04 PM
Guys,

Thank your for your postings. I see your points on the issue and am happy your around to correct me when I read articles/magazines relating to the AR's.

Thanks again,

Mail Clerk

duc748bip
05-18-2010, 12:13 PM
9mm/45acp won't penetrate soft armor at almost any range. Thus you see the move of Personal Defense Weapons (PDWs) to close that gap. You have new round like the FN 5.7 designed for SMG sized weapons able to penetrate soft armor. But why reinvent the wheel? A LWRC PSD SBR will do the same thing....

I don't claim to be a profeessional here just offering my two cents ;) maybe its the giant fireball from the unburnt powder and the busted ear drum from firing a rifle cartridge from a pistol length barrel? compounded by the fact you are firing indoor in an enclosed space. Come to think of it an SBR with a suppressor makes a great package ;) (Damn you CA.. hope you go bankrupt and let AZ buy you) :D

technique
05-18-2010, 4:18 PM
Alright...for some perspective.

These numbers are "estimates".."rough" if you will.

Your standard M193 55gr. stuff fragments at 2700fps and up.
Even from a 10.in barrel, I'm still getting above 2700fps.

Again, we aren't talking specialized ammo. We aren't talking soft points here, this is standard 55gr. FMJ.

Just sayin...

cmace22
05-18-2010, 4:32 PM
Alright...for some perspective.

These numbers are "estimates".."rough" if you will.

Your standard M193 55gr. stuff fragments at 2700fps and up.
Even from a 10.in barrel, I'm still getting above 2700fps.

Again, we aren't talking specialized ammo. We aren't talking soft points here, this is standard 55gr. FMJ.

Just sayin...

I think the real question is for how long. You may have 2700 at the muzzle but IIRC that m193 drops below 2700 at 75-150 yards.

I agree that when your range is within a few hundred yards an SBR may perform adequately. Heck I wouldn't want to be hit with anything no matter what the range.

But if your goal is to have the best terminal performance you better know what range and situation your packing for.

As for accuracy Ive read of people getting 1-2moa with an 8" at 100 yards.

Gio
05-18-2010, 4:33 PM
Here you go 75 gr Wolf HP at 330 yards / 300 meters out of a 7" GPU which I use for my AR Pistol.

h034rteEsLE

So far I have used MBUS at 100 yard and hit center mass shooting at a steel target. I have to dial in my EOTech 553 next time out, I've used Factory ammo and or M193 reloads so far in it.

technique
05-18-2010, 5:07 PM
I think the real question is for how long. You may have 2700 at the muzzle but IIRC that m193 drops below 2700 at 75-150 yards.

I agree that when your range is within a few hundred yards an SBR may perform adequately. Heck I wouldn't want to be hit with anything no matter what the range.

But if your goal is to have the best terminal performance you better know what range and situation your packing for.

As for accuracy Ive read of people getting 1-2moa with an 8" at 100 yards.


That's correct, numbers are from 5-6ft. from the muzzle ...and again SBRs are used at distances no longer than the longest distance in your household (CQB distances), normally a hallway. That's what? 20-30ft *average*?

I still wouldn't want to be hit with even a 55gr. at 100yrds.

sd1023x
05-18-2010, 5:59 PM
That's correct, numbers are from 5-6ft. from the muzzle ...and again SBRs are used at distances no longer than the longest distance in your household (CQB distances), normally a hallway. That's what? 20-30ft *average*?

I still wouldn't want to be hit with even a 55gr. at 100yrds.

Wow, I was under the assumption that in a 10 inch, your gonna be less that 2700fps. Guess I was wrong.

A ballistic chart....sort of. Its 52 gr and a bolt action, but for our purposes close enough. http://www.accuratereloading.com/223sb.html

technique
05-18-2010, 6:28 PM
Wow, I was under the assumption that in a 10 inch, your gonna be less that 2700fps. Guess I was wrong.

A ballistic chart....sort of. Its 52 gr and a bolt action, but for our purposes close enough. http://www.accuratereloading.com/223sb.html


That's a pretty cool little collection of data they have there, thanks for sharing it.
Yeah, looks they get as fast as 2818fps out of a 10in with some of their loads.

sd1023x
05-18-2010, 6:38 PM
That's a pretty cool little collection of data they have there, thanks for sharing it.
Yeah, looks they get as fast as 2818fps out of a 10in with some of their loads.

All about spreading the knowledge and stoppin the FUD. And damn u technique, now I have to reconsider my 10 inch pistol build!:D

technique
05-18-2010, 6:44 PM
All about spreading the knowledge and stoppin the FUD. And damn u technique, now I have to reconsider my 10 inch pistol build!:D

Well....I'm over here arguing that a 5.56 is actually effective from a 10in. barrel, I mean there is data that can support that to some extent...

On the other hand though...you're hearing this from a guy building a 10.5in. AR .308....soooooooooooo:D

Noobert
05-18-2010, 6:46 PM
Well....I'm over here arguing that a 5.56 is actually effective from a 10in. barrel, I mean there is data that can support that to some extent...

On the other hand though...you're hearing this from a guy building a 10.5in. AR .308....soooooooooooo:D

Pics or it didn't happen :cool:

Mail Clerk
05-18-2010, 7:15 PM
I think the real question is for how long. You may have 2700 at the muzzle but IIRC that m193 drops below 2700 at 75-150 yards.

I agree that when your range is within a few hundred yards an SBR may perform adequately. Heck I wouldn't want to be hit with anything no matter what the range.

But if your goal is to have the best terminal performance you better know what range and situation your packing for.

As for accuracy Ive read of people getting 1-2moa with an 8" at 100 yards.

cmace22,

Wow 1-2 MOA from such a short barrel AR at 100 yards???? That's pretty fantastic. So that means for a typical 55 grain bullet is stabilized with only an 8" barrel? I would think that at 100 yards the bullet might not even hit the target OR at least might keyhole the paper due to the bullet not being stable

It makes me wonder even more BUT no matter as long as there is a place for such a short barrel AR then the boat floats.

Mail Clerk

sd1023x
05-18-2010, 7:37 PM
Well....I'm over here arguing that a 5.56 is actually effective from a 10in. barrel, I mean there is data that can support that to some extent...

On the other hand though...you're hearing this from a guy building a 10.5in. AR .308....soooooooooooo:D

You gonna SBR that badboy?

technique
05-18-2010, 7:40 PM
You gonna SBR that badboy?

Yes. Just waiting on a tax stamp...this is a personal gun.
I'll have some pics up when I can legally assemble it, or...when I have the upper together (still needs a rail). But that's a story for another day!


Disclaimer: I have the luxury of a FFL07/SOT2, there are no constructive possession issues for me. That is all.

sd1023x
05-18-2010, 7:51 PM
Yesssss.....definitely gonna need some pics of that outrageous beast.

And I wanna move....I want silencers and sbrs....

dwa
05-18-2010, 7:59 PM
Oh and the other "SF" guy that engaged the vehicle and shot the kids by mistake was army...enough said,lol. Hoorah!!

how bout you stfu lol

http://www.marinecorpstimes.com/news/2008/02/marine_marsoc_080215/

heres some highlights

Then the unit bent every rule that wouldn’t break, ticked off every commander in the theater, alienated the local population, violated direct orders, caused an international incident, allegedly killed as many as 19 Afghan civilians and wounded dozens more.

So the Army sent the whole unit packing

One field-grade Army officer present in eastern Afghanistan at the time said the Marines were undone on two counts: “the issue of competence and the issue of integrity. ... The trust and confidence in these guys eroded.”

“It was those two incidents, in conjunction with the shootings — the ROE escalations — and the shooting that occurred on the 4th, that actually caused Colonel Haas to say, ‘You guys are confined to post — you’re not to leave without any express permission whatsoever,’” the CJSTOF-A source said.

“Colonel Haas was really pissed off at them. I mean, he was absolutely furious at them,” the CJSOTF-A source said. “It was a compilation of everything, because they were just acting like a bunch of cowboys and Colonel Haas had just had his fill and said, ‘Enough’s enough.’”

Sanchez, the Marine prosecutor at the court of inquiry, summed it up: “Normally, you want to give Marines the benefit of any doubt,” he told the court Jan. 29. “But in this case, you might not want to.”

1911su16b870
05-18-2010, 8:18 PM
Short AR barrels are really for CQB, ala door-to-door fighting i.e. Ramadi.

This thread gives the best representation of barrel length vs. velocity and is courtesy Randall (AR15barrels.com who really has great info on his site and is a very smart guy):

http://www.calguns.net/calgunforum/showpost.php?p=1780285&postcount=19

Bottom line is that 5.56 at over 2500 fps should fragment terminally, and if not, the temp wound channel should slow whatever was hit somewhat.

Yes those short barrel ARs can hit out to 300 yards, but your velocity may be much lower than required to do achieve your intended purpose.

Grumpyoldretiredcop
05-18-2010, 8:33 PM
cmace22,

Wow 1-2 MOA from such a short barrel AR at 100 yards???? That's pretty fantastic. So that means for a typical 55 grain bullet is stabilized with only an 8" barrel? I would think that at 100 yards the bullet might not even hit the target OR at least might keyhole the paper due to the bullet not being stable

It makes me wonder even more BUT no matter as long as there is a place for such a short barrel AR then the boat floats.

Mail Clerk

With an 11" barrel, 1X9 twist, firing 55 grain ammo, I'm getting more like 3-4 MOA at 100 yards. But, then again, that's with a Trijicon RX01 and my tired middleaged eyeballs. With some magnification, I might do better. There are no signs of keyholing. I suspect that I could be effective at 100 yards with this AR pistol, but it wouldn't be my first choice.

Jpach
05-18-2010, 10:39 PM
Yes. Just waiting on a tax stamp...this is a personal gun.
I'll have some pics up when I can legally assemble it, or...when I have the upper together (still needs a rail). But that's a story for another day!


Disclaimer: I have the luxury of a FFL07/SOT2, there are no constructive possession issues for me. That is all.

Does this mean you can be a middleman?

Mail Clerk
05-19-2010, 5:40 AM
With an 11" barrel, 1X9 twist, firing 55 grain ammo, I'm getting more like 3-4 MOA at 100 yards. But, then again, that's with a Trijicon RX01 and my tired middleaged eyeballs. With some magnification, I might do better. There are no signs of keyholing. I suspect that I could be effective at 100 yards with this AR pistol, but it wouldn't be my first choice.

Grumpyoldtiredcop,

The pic I saw in the magazine was not a pistol. It was definitly a sub machine gun/rifle type. My only wonder was why Robinson Arms would use the 223 round. Again many posting back I had thought why would anyone need a SBR to begin with. My question has been pretty much answered.

Mail Clerk

cmace22
05-19-2010, 6:27 AM
With an 11" barrel, 1X9 twist, firing 55 grain ammo, I'm getting more like 3-4 MOA at 100 yards. But, then again, that's with a Trijicon RX01 and my tired middleaged eyeballs. With some magnification, I might do better. There are no signs of keyholing. I suspect that I could be effective at 100 yards with this AR pistol, but it wouldn't be my first choice.


I would love to get 3-4 MOA with my 14.5 hahaha.

slagusmc
05-19-2010, 11:05 AM
Another case of army incompetance being pawned off on marines,lol. We go to afghanistan to save the army and look at the thanks we get,lol.

how bout you stfu lol

http://www.marinecorpstimes.com/news/2008/02/marine_marsoc_080215/

heres some highlights

fonionrings
05-19-2010, 11:30 AM
Here you go 75 gr Wolf HP at 330 yards / 300 meters out of a 7" GPU which I use for my AR Pistol.

Just wanna say how hilariously badass your Diablo looks with that scope on it! :chris:

Gio
05-19-2010, 11:38 AM
Just wanna say how hilariously badass your Diablo looks with that scope on it! :chris:

That was not my Diablo, I just meant I use that same upper for my AR Pistol. I would love to have it as an SBR instead but with a smaller more CQB Tactical 1-4X scope on it :laugh:

dwa
05-19-2010, 12:00 PM
Another case of army incompetance being pawned off on marines,lol. We go to afghanistan to save the army and look at the thanks we get,lol.

your serious? its from THE MARINE CORPS TIMES, I'm somewhat sceptical of you actually being a marine. you professional competence is severely lacking. The marines are in afghanistan because they asked to go there.

PIRATE14
05-19-2010, 1:08 PM
Well pretty sure max frag velocity for 5.56 is about 85 yds out of a 10.5 barrel, which is plenty in most scenarios that you would use a SBR for....there are charts for this some where and pretty sure someone would post one up shortly...

I can get sub moa with my noveske at 100yds and it's only 10.5.....so short barrels are mostly about velocity and has little to do with accuracy...

7.5 inch 5.56 barrels not so much of a good idea unless you got a suppressor for a lil velocity boost......

If ya want a 7.5 get one in 6.8....;)

Mail Clerk
05-20-2010, 6:02 AM
PIRATE,

Thanks for your posting. I saw on "You Tube" people shooting their SBR's at dsitances that I still can' believe is possible. I saw one that was hitting a metal plate at 300 yards! I may be dumb but that can't be possible even with his red dot scope. As far as velocity goes I'm not curious about that...... it's more of an accuracy thing cuz my origional question was "why would anyone shoot a 223/nato otta a SBR"???? I had thought that at a distance of 100 yards any type of accuracy is impossible. However since you can get sub MOA from your SBR now I wonder again.
I would like to get one (upper) day when and if the California laws relax but for now that doesn't appear possible currently unless it's has that super extended flash surpressor.

Thanks again for your posting.

Mail Clerk

Pvt. Cowboy
05-20-2010, 6:53 AM
Compared to my 16" barreled AR's I feel these would be completly useless as any type of service rifle in the field cuz it wouldn't give any good groups past 100 yards.

Others have already chimed in with their data, but I have an 11.5" barrel that prints really nice groups at 200. Stays on a man-sized gong at 300 and 400 with only a big fat EOTech recticle to aim through.

Mail Clerk
05-20-2010, 7:36 AM
Others have already chimed in with their data, but I have an 11.5" barrel that prints really nice groups at 200. Stays on a man-sized gong at 300 and 400 with only a big fat EOTech recticle to aim through.

Pvt. Cowboy,

May I ask what brand and grain ammo you used??? So far from my 16" using PMC/Winchester it does pretty good at 100 yards with just 55 grainers. Can't really find any 62 grain any where with a decent price to try.

Mail Clerk

1911su16b870
05-20-2010, 9:35 AM
Another thought...just as you may use +P ammo in your short-er barreled pistols (UCDP or G26/27) you could load 36-grain Varmint Grenades into your short barreled ARs for the higher velocities...

Anyone out there chrono a 36-grain Varmint Grenade out of a 7.5-inch AR upper???

Alex$
05-20-2010, 11:02 AM
http://www.midwayusa.com/viewProduct/?productNumber=541102

Sounds about the same as a 16" or 20" barrel, hits paper consistently out to 300. Don't bother with MOA analysis, just look for holes where I want them. (inside the target)

Untamed1972
05-20-2010, 12:27 PM
Hello to all,

This question is for you AR-15 gurus.

I was reading my latest issue of Guns and Weapons and noticed an advertisement for Robinson Arms which had a 9" barreled sub-machine guns type of rifle. It gave me the thought of why would anyone need a short barreled AR style rifle???? They even offered it in the 223 nato round.

Isn't these designed for CQB usage???? and so if they are would the short barrel stableize the 223 bullet?????

Compared to my 16" barreled AR's I feel these would be completly useless as any type of service rifle in the field cuz it wouldn't give any good groups past 100 yards.

If you guys feel different what amount of yards would this be useful???? Perhaps nothing more than 50 yards??? I highly doughbt 100 yards using 55 grains bullets.

Just curious...... Let me know what you think.

Mail Clerk


According to a former navy seal who was an instructor at a recent carbine course I attended......they rocked the 10"bbl M4s all day long and were still taking targets out to 600yds. With his wealth of recent real world combat experience....I will take his word for it.

Mail Clerk
05-20-2010, 3:38 PM
According to a former navy seal who was an instructor at a recent carbine course I attended......they rocked the 10"bbl M4s all day long and were still taking targets out to 600yds. With his wealth of recent real world combat experience....I will take his word for it.

Untamed1972,

That is simply amazing!!!!! I learn something everyday. I'd sure like to meet him to find out details how he did those.

Later,

Mail Clerk

Alex$
05-20-2010, 3:59 PM
Aim, squeeze, repeat as needed, breathe.

NiteQwill
05-20-2010, 5:06 PM
I have a 7.5" bbl (stainless steel) and hit 150-200 yd steel all day long. Unless I had a reason for touching someone or something long range, I'd opt to run an SBR all day long in a 7.5 or 10 configuration simply because of maneuverability and weight.

This is using M855, XM193, or Federal bulk.
http://www.sk8ng.com/dusty/wp-content/uploads/2010/05/AR-Barrel.jpg

Mail Clerk
05-20-2010, 7:05 PM
NiteQwill,

You have a most pretty rifle for a SBR form. Unfortunatly for me that's illegal where I live and can only drewl at having one some day. The best I've seen was at CWS where it had a long 5 1/2 " flash surpressor but it's never available when I have cash at hand.

Still looking for a Stag upper completely flat top but trying to save a few bucks and paying off cc until one comes along.

Too many toys and just not enough bucks and bad timing on my part. Maybe I'll just spend 30 bucks on gas and go see them anyway for a quicky look along with me check book just in case.:-)

Mail Clerk