7.5" or 10.5" Barrel? - Page 1

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[ARCHIVED THREAD] - 7.5" or 10.5" Barrel?

Posted: 4/22/2015 1:50:30 AM EDT

I'm close to finishing my first pistol build. All I have left to obtain is the barrel and BCG. I'm on the fence between the 7.5 and the 10.5. HELP ME DECIDE!

Posted: 4/22/2015 3:06:40 AM EDT

[#1]

I said 10.5" because of the increased reliability problems you get into when going to 7".

If a gun doesn't function reliably with new standard parts, and you have to add a mod that is meant to increase the life of the extractor spring just for it to run, then it is borderline unfunctional. Even if it seems to be okay under ideal conditions at the beginning of its life.

Posted: 4/22/2015 6:53:53 AM EDT

[#2]

11.5

Posted: 4/22/2015 8:46:18 AM EDT

[#3]

get both. i have a 4.5" .22, 7.5" in both 5.56 and 7.62x39 and a 10.5" 5.56. all run great

Posted: 4/22/2015 9:49:06 AM EDT

[#4]

I voted 10.5" because I was in the same boat for my Blackout build. I was torn between 7.5-8" or 10.5". I decided on 10.5" because I wanted to be certain I got a complete burn with the powder, and 10.5 seemed like a decent length that wasn't too long or too short. Cool thing is, I can dump the barrel if I want something shorter or longer, as I am only out $110 for the barrel, and buy another barrel for about the same if I can catch the deals.

Posted: 4/22/2015 6:31:23 PM EDT

[#5]

7.5. If your gonna build a pistol make it a pistol. 7.5 with a 2inch muzzle device is pretty close to 10 inches anyway.

Posted: 4/22/2015 7:45:40 PM EDT

[#6]

From my research (owner reports of issues and requests for help) I found the 10.5" worked best for the .223/5.56 pistol and 7.5"~8.5" for the 300 BLK. Their issues were primarily FTF and FTE and solutions ran the gambit from enlarging the gas port opening, adjustable gas blocks and swapping out the buffer for a different weighted one.

I have one of each, 10.5" in .223/5.56 with carbine length gas system and the 300 BLK is 7.5" with pistol length gas, both with standard carbine weighted buffers. No issues with either.

Posted: 4/22/2015 8:26:49 PM EDT

[#7]

I went with a 10.5 on my first build. She runs like a top. In the process of building a 7.5 now.

Posted: 4/23/2015 8:36:44 AM EDT

[#8]

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I went with a 10.5 on my first build. She runs like a top. In the process of building a 7.5 now.

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This, always get both. But if you can't afford it at the same time, my vote is 10.5" first. I really like mine a lot.

Posted: 4/23/2015 5:01:00 PM EDT

[#9]

10.5 is good for 5.56/223. Mine was good to 200 yards. That said... I prefer an 11.5 or a 12" barrel for ballistics and range while still retaining good maneuverability
.

Posted: 4/23/2015 5:28:50 PM EDT

[#10]

Without question the 10.5"

Posted: 4/26/2015 12:06:36 AM EDT

[#11]

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Without question the 10.5"

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He knows what he is talking about!!!

Posted: 4/26/2015 12:34:50 AM EDT

[#12]

got rid of my 7.5 with kx3 because it was loud as hell. still rattles your teeth with ear plugs and ear muffs. i vote 10.5

Posted: 4/26/2015 3:16:48 AM EDT

[#13]

11.5"

Posted: 4/26/2015 9:18:45 AM EDT

[#14]

Both. My 10.5" is the HD AR, while my 7.5" wears a Law Tactical adapter and rides in a backpack.

Posted: 4/26/2015 9:53:57 AM EDT

[#15]

Started with 7.5", just got my 10.5" upper from a member (Andro corp) and I couldn't be more pleased. 7.5" will be a pistol with 10.5" suppressed SBR. Get both. Now for another 9mm AR, a 10.5" 7.62 build, more SBR lowers and cans. And a .308 build. BRD is real and I am well stricken!

Posted: 4/26/2015 5:58:54 PM EDT

[#16]

I too am in the "both" camp. Build or purchase either one than do the same for the other. You'll be happy you did both. Both have their pros and cons but there is no denying that they both are fun and capable.

Posted: 4/27/2015 1:07:39 AM EDT

[#17]

I like the small size of my 7.5" 300blk. Using a linear comp or flash diverter takes all the sting out of the shorter barrel.

I went 10.5" with the 223. It's fun too, but the 7.5" is like a blond on the beach... everyone has to look.

Posted: 4/27/2015 1:16:08 PM EDT

[#18]

10.5 in 5.56'. It may be a pistol but nobody shoots it with one hand.

Holster it and the knives start getting sharpened.

As long as it's under 26" - its a pistol. Over, it could be a firearm - and then it won't fall under CCW language cause that's all about it being a pistol under 26".

Shoot it with two hands, perfectly legal with any pistol. Hold it high, tight to the cheek with nose on the charging handle - which few handguns will tolerate - and enjoy. Don't forget to wear muffs and plugs. I suggest at least electronic amplified ones starting at the $90 level. Way cheaper than a silencer, they suppress any other gun around you, too, and you can hear a fly sneeze at 50 yards.

Posted: 4/27/2015 2:01:38 PM EDT

[#19]

Quote History

Quoted:
10.5 in 5.56'. It may be a pistol but nobody shoots it with one hand.

Holster it and the knives start getting sharpened.

As long as it's under 26" - its a pistol. Over, it could be a firearm - and then it won't fall under CCW language cause that's all about it being a pistol under 26".

Shoot it with two hands, perfectly legal with any pistol. Hold it high, tight to the cheek with nose on the charging handle - which few handguns will tolerate - and enjoy. Don't forget to wear muffs and plugs. I suggest at least electronic amplified ones starting at the $90 level. Way cheaper than a silencer, they suppress any other gun around you, too, and you can hear a fly sneeze at 50 yards.

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Not exactly.

1) A holster has no determination on the status of a concealed/openly carried handgun. People open carry in a holster all the time. Not that you can reasonably holster a 10.5" AR pistol anyway.

2) Lacking a stock makes it a pistol, not the overall length.

3) The addition of a vert. fore grip would then make the "pistol" into an AOW (if the overall length is less than 26") or a firearm (if the overall length is 26+").

Posted: 4/27/2015 2:11:52 PM EDT

[#20]

7.5 300Blk

Posted: 4/27/2015 10:12:50 PM EDT

[#21]

10 if cereal, 7 for fun.

The only thing that has gotten my 7" to give me issues is to run a few hundred rounds of some really dirty 22lr with a conversion first without lube. It was so caked up it was hard to charge and failed to go fully into battery a few times. Lesson learned. I'll be wettin' it up next time I do the same.

My 10.5 doesn't feel much different from a 16" carbine...just a bit louder

The 7" is a frikkin' riot with 5.56.

Posted: 4/28/2015 1:02:30 PM EDT

[#22]

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11.5

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Posted: 4/28/2015 8:56:09 PM EDT

[#23]

10.5 love mine.

Posted: 4/30/2015 11:28:46 AM EDT

[#24]

I voted 7.5
I built a 10.5 first as a pistol and now I have a form 1 in to SBR it.
Then I built an 7.5 pistol and love it, put a Thorsden buffer tube kit on it and its sick.
Also have a 8" 300 blk with a over the suppressor rail on it, that has a form 1 in as well.

Posted: 4/30/2015 7:16:09 PM EDT

[#25]

I'm building my first AR pistol and am using a 7.5" $100 psa barrel and a 3" blast can. Makes it about 9.5" long. If I was to do a 10", I'd use a A2 FH to keep it short.

Posted: 4/30/2015 9:00:30 PM EDT

[#26]

It ultimately depends on what you want to do with it. the only firearm I've ever bought for a specific purpose was my glock 23 for carry. Everything else I own was because i just want it. The 10.5 is more usable in that is retains enough velocity to reliably fragment. I didn't build my first AR pistol to be practical, or have a specific reason to build it. So I said screw it and built a 7.5 despite numerous people saying it won't be reliable, it's stupid, it's useless, yada yada yada. I built it to have fun at the range and piss off anyone to my left and right. It accomplished all of that more than I ever imagined. If you want a 7.5 just know that it's a novelty, depending on muzzle device it's incredibly loud and produces muzzle flash that would make a m44 blush.

Posted: 6/4/2015 5:19:24 PM EDT

[#27]

10.5". I was so excited to shoot my 7.5" sbr today. Shot it twice and put it away. Indoors, it is an ear drum burster. It might be cool on an outdoor range, but never again indoors...

Posted: 6/4/2015 5:21:03 PM EDT

[#28]

My SBR is a 16" Heavy Barrel cut down to 10.5" and I have had zero issues with it.

Posted: 6/4/2015 5:24:13 PM EDT

[#29]

If it's for fun, 7.5". If it's for work, 10".

Posted: 6/4/2015 5:37:14 PM EDT

[#30]

I have both. The size difference between the 2 isn't much. I like both. The 7.5 is the coolest looking. The 10.5 is easier to hold onto the fore end and shoot better I guess. If all you are doing is shooting paper the 7.5 will win cool factor points, put if you plan on doing any hunting or defensive work the 10.5 is probably "better", but there are actually LE agencies useing 7.5" barrels.

Posted: 6/4/2015 6:57:26 PM EDT

[#31]

Quote History

Quoted:
I have both. The size difference between the 2 isn't much. I like both. The 7.5 is the coolest looking. The 10.5 is easier to hold onto the fore end and shoot better I guess. If all you are doing is shooting paper the 7.5 will win cool factor points, put if you plan on doing any hunting or defensive work the 10.5 is probably "better", but there are actually LE agencies useing 7.5" barrels.

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Do you know if the LE agencies are using suppressors? I agree that they do look pretty cool!

Posted: 6/4/2015 9:39:42 PM EDT

[#32]

Quote History

Quoted:

Do you know if the LE agencies are using suppressors? I agree that they do look pretty cool!

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Quote History

Quoted:

Quoted:
I have both. The size difference between the 2 isn't much. I like both. The 7.5 is the coolest looking. The 10.5 is easier to hold onto the fore end and shoot better I guess. If all you are doing is shooting paper the 7.5 will win cool factor points, put if you plan on doing any hunting or defensive work the 10.5 is probably "better", but there are actually LE agencies useing 7.5" barrels.

Do you know if the LE agencies are using suppressors? I agree that they do look pretty cool!

No, don't know, just know I found LEOs on another forum discussing use of the DPMS Kitty Kat as an issued weapon. DPMS, I believe, only sells kitty kats to agencies.

Posted: 6/5/2015 9:48:49 AM EDT

[#33]

10.5" 5.56 Radical pistol here - 300 rounds in and no problems.

Posted: 6/5/2015 10:09:11 AM EDT

[#34]

I voted for 7.5 but "get both" is also a good answer.
Bought mine already built so I haven't had any reliability issues.

It's fits in a racket bag and it's easy to take along anywhere that my CCW is legal.
I have a CQB muzzle device on it so noise and fireball aren't bad at all.
Chest hits at 100 yards with a red dot.

At the Active Response Training website they got 12-16" penetration from a 7.5" barrel at 83 yards in ballistic gel.
http://www.activeresponsetraining.net/ar-15-pistol-ballistic-gel-testing

What's not to like?
(It's a pain to make the link hot from my IPhone.)

Posted: 6/5/2015 3:16:09 PM EDT

[#35]

10.5" A 7.5" is just a really loud .22. The projectile never makes fragmentation velocity even at the muzzle, so if you want it to be effective, you'll need some kind of expanding bullet.

If you are going to go 10.5", go 11.5" instead to get a little more dwell time and better reliability.

Posted: 6/5/2015 3:22:07 PM EDT

[#36]

Call it a hunch but if this thread were in a section other than the pistol forum, the votes would be even higher for 10.5".

Posted: 6/6/2015 8:37:39 AM EDT

[#37]

10.5

Posted: 6/6/2015 9:52:57 PM EDT

[#38]

neither .......
get a 7" for 79 bucks and make big fire.

http://www.centerfiresystems.com/bbl0001.aspx

Posted: 6/13/2015 5:13:56 PM EDT

[#39]

I built a pistol because I wanted it to be short so I went 7.5". Runs like a top for 7 years now without one single issue. Certainly more than just a .22. I am not in the military why would I handicap myself with military ammo? I don't need fragmentation velocities.