Why no 20 inch?

[Yendor357]

By now he has found something new to be dissatisfied.

Condensed version after running the numbers: The 16 inch AR at 500 yards is the equivalent of my 24 inch 5R barreled REM at 575. That seems like a fair trade off for 8 inches less barrel on the AR-10.

 

[smoothshooter]

I wouldn't say optimized. I would call the 18" barrel the best compromise for .308.

What about increased muzzle blast?

 

[smoothshooter]

That's something you'd have to ask S&W about directly. My guess, is that since it is possible to hit targets out to 750ish yards out of the box that S&W thinks it's good enough. Max effective range for .308 when taking game is about 800 yards anyway. 2 more inches of barrel might give you 1,000 yards but even then the limits of the round's capability is being met or exceeded. Punching paper or hitting a steel target is a bit of a different animal since round lethality isn't a concern.[/QUOTE

Anyone shooting at living creatures ( excepting enemy soldiers ) at distances approaching of 800 yards with ANY hunting cartridge is simply being irresponsible.
Be better hunters. Get closer.
Or pass up the shot.

 

[Mike SC Hunter]

I would question even remotely thinking of the .308 as an 800 yard game cartridge. To much chance the animal will move while the bullet is en route to the target, resulting in a crippling shot. Bullet performance is pretty iffy at that distance too.

If you take 800 yd shots at game you need to become a better hunter and get closer.

 

[WI357SIG]

Ruger SFAR Rifle (Small Frame AR) in .308 comes in either 16" or 20" barrel. My son just purchased the 20" version. What a sweet package.

 

[Racer X]

To just get a .243 Winchester upper for the gun.

or a 6 or 6.5 Creedmore.

 

[Yendor357]

1000 yards hits on a 24”X24” steel plate with a 308 is not all that terribly difficult. If I can do it, it can’t be too hard. Get out there and try it. You’ll see.

Muzzle blast? Muffs over plugs. Or a suppressor.

I have 6.5 Creeds in an AR-10 and a REM 700. Both wear Kreiger barrels. They’re easier to impact with. I don’t care what the charts say, those 6.5s don’t hit as hard as that good old .308.

 

[jjrr]

My experience with 308 at 1000 from the national matches years ago, I was shooting 180gr smk bullets in my M1A and I had the opportunity to talk to the guys who were pulling my target and they told that my bullets were yawing bad or tumbling when they went thru the target. In the same match I scored for a national guard shooter who was hammering the 10 ring with a M14 and he told me he was shooting 180smk with a max load of 4064 powder. 308 will work at 1000 but that is about the limit reasonably.

 

[Yendor357]

JR, Do you know what rate of twist was in your M1A? Was it the 1 in 11.25”?

Maybe the National Guardsman had a 1 in 10?

I remember some of the service guys shooting hot loads. The op rod made a “ping” noise. They wouldn’t reload that brass.

 

[jjrr]

JR, Do you know what rate of twist was in your M1A? Was it the 1 in 11.25”?

Maybe the National Guardsman had a 1 in 10?

I remember some of the service guys shooting hot loads. The op rod made a “ping” noise. They wouldn’t reload that brass.

My gun has I:10 I still have it although I havent shot it in a long time. The advantage he had was a heavier load and he was no doubt a better rifleman. I have no idea what barrel the guard was using.

 

[jjrr]

I don’t want to hijack the op’s thread but to his point the physics involved in launching a bullet and have it land in relatively the same spot 1000 yards away twenty times is a feat that requires experience and equipment and the barrel length to give you the velocity with the 308 is a huge part of the equation.

 

[Yendor357]

A 175 Sierra started out at 2565 fps from my Remington 5R is going 1230 fps at 1000. Once you’re zeroed, on a relatively calm day, you’ll get a lot of hits on a 24 inch square at 1000. I’ve done it. That’s a pretty mild load for that rifle.

Can you get 2565 with a 175 in 16 inches? I’m not willing to push it in an AR. When I need hot loads, I buy factory ammo. I’ll let someone else do the testing with their equipment. Hornady factory 165 is doing 2665 out of my 16 inch AR-10. So in theory it’s possible. Maybe one of these days I’ll put a big scope on my 10 and put all this theory to the test.

 

[WR Moore]

Having shot .308 at 600 & 1000 yard F class matches I noticed a few things. Note: I was using the then SMK Palma 155 gr bullet. The current Palma bullet has a BC over .500. I got lots less drop at 1K and the wind drift @ 2850 f/s was same/same as the 175 SMK at lower velocities.

1. 600 yards is basic ballistic math and shooting fundamentals. Wind is a consideration, but easily coped with.

2. 1K is still fundamentals, but judging the wind is an art form.

3. I got to shoot a national class winning rifle with a Nightforce scope. They may well be worth the money (I could see scoring rings at 1K), but I can't afford them.