14" 308 Bolt gun, anyone SBR one? Considering short Ruger Scout

[Failure2Stop]

I agree on the short 308 being a bad idea overall.

Velocity wise, yes they are going to be close, but look at the bullet weights. With the 308 out of a fairly short barrel you are still pushing that 2200-2400 fps mark with a 175g+ bullet. You will NEVER do that with 300blk, it just doesnt have the powder capacity. With the 110g Barnes at 2400 FPS you are at like 1400ft. lbs of energy. With a 175 at 2400 FPS you are at 2200ft. Lbs.

Like I said I am pushing 150g bullets out of 300blk at like 1800fps MAX(probably more in the 1700 range). I dont know what a 175g would do since I dont believe there is a load that will run an AR. I would guess out of a bolt gun you would see a 175g SMK running around 1400-1500 FPS. Take a 175 out of a 16" 308 bolt gun and you could still run in up in the 2400+ range VERY easily. Even out of a 14" bolt gun the 308 could still probably run in the high 2200 FPS range where the blackout would probably be in the 1300 FPS range.

You cant IMO just say muzzle velocity is the same thus terminal effects are the same. Now bullet selection can mitigate things a bit, but only to a point. When you are almost double the energy down range due to being able to push 35-40% more bullet at the same speed, the 308 is going to win every time IMO from a terminal effects stand point. But like you said you run into a lot more issues going short in the 308 and its not really worth it.

Absolutely agree on the terminal effect side of the discussion, neither 7.62 or .300 BLK is going to be pushing a round fast enough out of a 14" barrel to really tell the difference. Neither is going to dramatically fragment, and both will be dependent on bullet design to do the job at impact velocity. So, if they're both going to perform essentially the same, why bother with 7.62 and the associated blast?
ETA- I only discussed velocity because that's what was brought up, and I care far less about energy than I do about what the bullet actually does when it hits.

We're not talking about a gunfighter's carbine, so the discussion of weight carried and magazine capacity isn't much of a factor in the problem, agreed.

Mk319 Mod 0 works well out of short barrels (14" range), but everything else is built around a longer barrel, which means more blast, which also means more suppressor wear. It is also an issue of rotational stability. The 175 grain lengths at 14" barrel velocities, even out of a 1:10 twist, is perilously questionable as far as stability. .300 BLK has a faster twist rate to compensate for slow, long bullets, from short barrels which translates to really nice performance when the barrels are lengthened to what would be a dangerously short 7.62 barrel.

The interesting thing is that 16" 7.62 guns perform well (in both precision and function if talking gas guns, which we aren't), and I prefer them to pretty much any other 7.62 option. It's odd how much difference 2" can make.

[ALCOAR]

LMT MWS 13.5" full auto suppressed testing.....

LMT makes it looks damn easy....and that's some serious firepower imho

[Failure2Stop]

LMT MWS 13.5" full auto suppressed testing.....

LMT makes it looks damn easy....and that's some serious firepower imho

I've also shot short barreled Mk48s suppressed.
The cans do not look pretty afterward, have a severely reduced lifespan, are significantly louder, and have significantly more flash than their long barreled counterparts.

It doesn't make one a bad person for wanting to try it out, but I don't recommend it.

[xjustintimex]

I use my rem 700 aac with a 16" barrel for hunting and love it. I've also taken it out to 900 yards using fed gold medal match 175g. I can't see a reason going shorter than that. The scout rifle seems longer just because of the front sight and flash hider I think. I have not tried taking them off of my scout.. but for the length I wish that it was 18"

[ICANHITHIMMAN]

So you want this with a stock (14" barrel)? I don't see it as being worth the paperwork, this one is currently in 243 (2950 fps 85g SBT) and the scope has been upgraded, the ballistics however will surprise you. Just food for thought as the barrel length debate comes up so much.

I would guess around 2400 fps with a 180g 30 cal bullet from a 14" barreled 308.

[DocGKR]

Fully agree with everything F2S wrote above.

[ICANHITHIMMAN]

Here is a link to a ballistics chart from one of my favorite companies, my assumption is they are hand loads.

http://www.moaguns.com/ballistics.html