.308 Ballistics out of >16" bbls

CarbineOne

CarbineOne

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Anyone have any insight to share?

16" is generally as low as most people are willing to go... I was thinking of building a 14" or even a 12" .308 carbine, but was curious as to how drastically the performance is effected by shorter barrels.

Cheers!
 
There is plenty of data for those short barreled .308s, just look in the single shot pistol section in a good reloading manual. You loose and you gain with the short barrel, you loose lots of velocity and you gain lots of noise and blast.
 
i remember seeing an article in g&a years ago about a 16 or 14 inch m14- the guy used a gas assembly of an m60 - had to change to both a LIGHTER bullet and a FASTER POWDER- or that was the gist of it- bottom line was that there was a MINIMAL advantage over an 18 inch- which is what most carbines are
 
The biggest gain would be in the uberkewlness.
And with the right brake, one would have the range to oneself.
 
ben hunchak said:
There is plenty of data for those short barreled .308s, just look in the single shot pistol section in a good reloading manual. You loose and you gain with the short barrel, you loose lots of velocity and you gain lots of noise and blast.
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Forgot to mention with shorter barrel you have better portability and rifle is more managable in tight spaces. Sure, it's only 4 inches, but as marginal as that sounds it does make a difference when handling the rifle.
 
Demon971 said:
Forgot to mention with shorter barrel you have better portability and rifle is more managable in tight spaces. Sure, it's only 4 inches, but as marginal as that sounds it does make a difference when handling the rifle.
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True enough.
But its a restricted rifle. Range use only. Are portability and manoeverability in tight spaces important?
Does anyone campaign 3-gun competition with a .308?
 
tiriaq said:
True enough.
But its a restricted rifle. Range use only. Are portability and manoeverability in tight spaces important?
Does anyone campaign 3-gun competition with a .308?
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I do.
I use my 1911 and my M14. We have a different heat as opposed to the other's who use 223 or x39 to compete. I feel it gives me an better chance to win since there is less people in the heats :D
 
Fixit said:
sure are... ive been considering chopping down my m700 from 24" to something that would be alot easier to carry through the thick brush. i was thinking 18-20 "
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True enough. I use an 18 1/2" carbine myself. But the OP was wondering about restricted rifles as short as 12" in .308. Not many ranges extend through thick brush.
 
tiriaq said:
True enough. I use an 18 1/2" carbine myself. But the OP was wondering about restricted rifles as short as 12" in .308. Not many ranges extend through thick brush.
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I don't care about it being restricted, I'm not hunting with an AR-10 ;)

16" seems absolutely fine. I'm more curious as to the performance of 12"-14". HK makes their 417" in a 12". POF has one in 12.5". LWRC has a 12" as well. Merely curious as to ballistics, etc.
 
PWS is now offering Gas Piston .308 Carbines (their MK2 series rifles)...

Currently there are 3 barrel lengths: 12.5" / 14.0" / 16.1"

MK216 Specifications
Caliber 7.62x51 NATO
Weight 8 lbs, 12 oz (3.96 kg)
Overall Length 34.9" (88.5 cm)
Barrel Length 16.1" (40.9 cm)
Barrel Specs Stainless Steel, Isonite™ Treated, Button Rifled, 1:10 Twist Barrel
Muzzle Velocity 2600 ft/sec (168 gr FMJ)
Muzzle Energy 2522 ft/lbs

MK214 Specifications
Caliber 7.62x51 NATO
Weight 8 lbs, 10 oz (3.9 kg)
Overall Length 32.75" (83.1 cm)
Barrel Length 14" (40.9 cm)
Barrel Specs Stainless Steel, Isonite™ Treated, Button Rifled, 1:10 Twist Barrel
Muzzle Velocity 2500 ft/sec (168gr FMJ)
Muzzle Energy 2331 ft/lbs

MK212 Specifications
Caliber 7.62x51 NATO
Weight 8 lbs, 6 oz (3.79 kg)
Overall Length 31.4" (79.75 cm)
Barrel Length 12.5" (31.75 cm)
Barrel Specs Stainless Steel, Isonite™ Treated, Button Rifled, 1:10 Twist Barrel
Muzzle Velocity 2400 ft/sec (168 gr FMJ)
Muzzle Energy 2149 ft/lbs

Mark
 
"...a 14" or even a 12" .308..." Waste of time and money. Far too much velocity loss and far too much muzzle flash and noise increase.
 
sunray said:
"...a 14" or even a 12" .308..." Waste of time and money. Far too much velocity loss and far too much muzzle flash and noise increase.
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In your opinion.

Since these are NOT being designed and built specifically with Canadian paper punchers in mind as the primary end-user, there are applications where they do make some sense.

Since many of the intended end-users will mount sound suppressors on these shorter guns, the issue of muzzle flash and noise isn't really relevant. As for the velocity loss, I would suggest that at short CQB distances they still carry enough velocity to get the job done.

And that's just my opinion. ;)

Mark
 
the 12" is still very capable out to 300M. plenty of gun in a nice compact setup. I can see the benefits. Like the noise from a 12 incher will give away the position more so than from a 16" or even 26"? If one played a bit with powder chances are the velocities could be recovered.
 
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