.223 AR style rifles, 18" or 20" on a 1:8??

deadzero · 11-04-2009, 01:09 PM

I have a 20" Colt 5.56 H-Bar AR15-A2 1:7 but it has a carry handle. I was thinking of buying another upper but, I got a rifle shipped in last week I'm thinking about. it is the Remington R-15 carbine with a 18" heavy barrel 1:8 with a collapsable stock. for shooting 223 ammo this will be more accurate than the 5.56 chamber but I started wondering. comparing 2 guns that are the same otherwise like the Rem. R 15 20" heavy barrel to the 18" heavy barrel, both in .223 on a 1:8 twist, do you think there would be any difference in accuracy? the shorter barrel would be a little stiffer in relation to barrel dynamics when firing it seems. I was just wondering what others may think on this before I jump up and buy one. (once I buy the upper and the stock for the 5.56, I'm not really going to save much over just buying another one)

at4rxj · 11-04-2009, 02:25 PM

No difference that you'll notice... If anything, it would be so minimal it would be irrelevant.

Paper · 11-04-2009, 06:26 PM

Quote:

Originally Posted by at4rxj

No difference that you'll notice... If anything, it would be so minimal it would be irrelevant.

I couldn't agree more..

ZombieHunter · 11-04-2009, 06:47 PM

Quote:

Originally Posted by deadzero

I have a 20" Colt 5.56 H-Bar AR15-A2 1:7 but it has a carry handle. I was thinking of buying another upper but, I got a rifle shipped in last week I'm thinking about. it is the Remington R-15 carbine with a 18" heavy barrel 1:8 with a collapsable stock. for shooting 223 ammo this will be more accurate than the 5.56 chamber but I started wondering. comparing 2 guns that are the same otherwise like the Rem. R 15 20" heavy barrel to the 18" heavy barrel, both in .223 on a 1:8 twist, do you think there would be any difference in accuracy? the shorter barrel would be a little stiffer in relation to barrel dynamics when firing it seems. I was just wondering what others may think on this before I jump up and buy one. (once I buy the upper and the stock for the 5.56, I'm not really going to save much over just buying another one)

I have the 20" HBL in the 1:8, and it works just fine. The "stiffness" of the barrel, when we're talking about a 2" difference in something made of fairly thick steel less than 2' long, is negligible. If anything, I'd be looking at barrel length with regard to the number of rotations being forced upon the round before it leaves the barrel...but again, when we're talking about two inches, you aren't gonna notice a difference.

In fact, even the weight savings you'd get from losing those two inches wouldn't even really be worth mentioning.

The only advantage I'm seeing here is an 18" barrel being slightly more maneuverable when being hauled around inside a vehicle while not cased, and again...not likely to be an issue.

My guess? Go with whatever is cheaper. If they're the same price, go with what you think looks coolest.

jrswanson1 · 11-04-2009, 06:53 PM

Accuracy wise, those two barrel lengths should be neck and neck. However, you'll get more velocity out of the 20" versus the 18".

Jim

deadzero · 11-04-2009, 07:12 PM

my mistake. the standard model has a 22" barrel. I set the 18" carbine in the hold area with my name on it. I kind of like the shorter barrel. if I'm not really giving anything up, I'm going to go with it. it is short, light, and manuverable. I'll play with it using a red dot till the break in is done. than drop a scope on temporarly to see what it can do later. I got tomorrow off and heading to the range, kind of wish I had picked it up today to take with me. thanks for your help.
criss

ZombieHunter · 11-04-2009, 07:59 PM

Quote:

Originally Posted by jrswanson1

Accuracy wise, those two barrel lengths should be neck and neck. However, you'll get more velocity out of the 20" versus the 18".

Jim

How much of a difference do you think it would make, between the 20" and the 18"?

Also, knowing now that it is a 22" he's looking at, will the velocity difference be significantly higher?

jrswanson1 · 11-04-2009, 10:30 PM

Quote:

Originally Posted by ZombieHunter

How much of a difference do you think it would make, between the 20" and the 18"?

Also, knowing now that it is a 22" he's looking at, will the velocity difference be significantly higher?

Going from memory, about 100 fps per inch of barrel length, depending on the cartridge. This should be true of the .223.

Jim

deadzero · 11-05-2009, 06:54 AM

the book says 18" on the R-15 VTR Predator carbine CS model and 22" on the R-15 VTR Predator rifle. but sitting side by side on the gun rack it looks like only a 2" difference. thats why I thought it was 20". as soon as I find where one of my employees decided to put my tape measure, I'll know for sure. but it don't look like a 4" difference.

a 100 fps per inch seems a bit much.

NY Marksman · 11-07-2009, 04:00 PM

I have the 22 inch version of the R-15. I will admit that I wish I would have been able to get the shorter model only because of the reasons stated about maneuverability, but they didn't have one at the time so I bought the 22 inch model. I am quite satisfied with it's accuracy and since I'm using it as a bench rifle the length is actually a plus. The R-15 is a great rifle.

twinson · 11-13-2009, 08:24 AM

I'd opt for the 20" 1:7 twist.

11-04-2009, 01:09 PM	#1
deadzero Senior Member Join Date: Dec 2008 Location: deep in the swamps SC Posts: 1,199	.223 AR style rifles, 18" or 20" on a 1:8?? I have a 20" Colt 5.56 H-Bar AR15-A2 1:7 but it has a carry handle. I was thinking of buying another upper but, I got a rifle shipped in last week I'm thinking about. it is the Remington R-15 carbine with a 18" heavy barrel 1:8 with a collapsable stock. for shooting 223 ammo this will be more accurate than the 5.56 chamber but I started wondering. comparing 2 guns that are the same otherwise like the Rem. R 15 20" heavy barrel to the 18" heavy barrel, both in .223 on a 1:8 twist, do you think there would be any difference in accuracy? the shorter barrel would be a little stiffer in relation to barrel dynamics when firing it seems. I was just wondering what others may think on this before I jump up and buy one. (once I buy the upper and the stock for the 5.56, I'm not really going to save much over just buying another one) __________________ If I need more than 1 shot, I need more practice.

11-04-2009, 02:25 PM	#2
at4rxj Senior Member Join Date: Oct 2005 Location: Houston, TX Posts: 1,109 Images: 10	No difference that you'll notice... If anything, it would be so minimal it would be irrelevant. __________________ modulARweapons.com

11-04-2009, 07:12 PM	#6
deadzero Senior Member Join Date: Dec 2008 Location: deep in the swamps SC Posts: 1,199	my mistake. the standard model has a 22" barrel. I set the 18" carbine in the hold area with my name on it. I kind of like the shorter barrel. if I'm not really giving anything up, I'm going to go with it. it is short, light, and manuverable. I'll play with it using a red dot till the break in is done. than drop a scope on temporarly to see what it can do later. I got tomorrow off and heading to the range, kind of wish I had picked it up today to take with me. thanks for your help. criss __________________ If I need more than 1 shot, I need more practice.

11-05-2009, 06:54 AM	#9
deadzero Senior Member Join Date: Dec 2008 Location: deep in the swamps SC Posts: 1,199	the book says 18" on the R-15 VTR Predator carbine CS model and 22" on the R-15 VTR Predator rifle. but sitting side by side on the gun rack it looks like only a 2" difference. thats why I thought it was 20". as soon as I find where one of my employees decided to put my tape measure, I'll know for sure. but it don't look like a 4" difference. a 100 fps per inch seems a bit much. __________________ If I need more than 1 shot, I need more practice.

11-13-2009, 08:24 AM	#11
twinson Member Join Date: May 2009 Posts: 19	Barrel I'd opt for the 20" 1:7 twist.

11-04-2009, 06:53 PM	#5
jrswanson1 Senior Member Join Date: May 2007 Posts: 1,093	Accuracy wise, those two barrel lengths should be neck and neck. However, you'll get more velocity out of the 20" versus the 18". Jim

11-07-2009, 04:00 PM	#10
NY Marksman Member Join Date: Jan 2007 Location: Lower Hudson Valley NY Posts: 51 Images: 3	I have the 22 inch version of the R-15. I will admit that I wish I would have been able to get the shorter model only because of the reasons stated about maneuverability, but they didn't have one at the time so I bought the 22 inch model. I am quite satisfied with it's accuracy and since I'm using it as a bench rifle the length is actually a plus. The R-15 is a great rifle.