Thread: 308 barrel length velocity loss

Originally Posted by Kelton

The 18” .308s I load for are brilliant 168 amax and 178 eldm crazy accuracy one has a hardy the other a dpt and it pains me to say it but the hardy is a fair bit quieter

Ah but which Hardy ? Stealth, compact...... ? how does your hardy compare to the dpt size, weight and muzzle forward length ?
No hate, genuine curiosity

Originally Posted by Kelton

The 18” .308s I load for are brilliant 168 amax and 178 eldm crazy accuracy one has a hardy the other a dpt and it pains me to say it but the hardy is a fair bit quieter

168s in the 18 inch 308 is killer!

Originally Posted by HNTMAD

Rule of thumb is 50 fps per 1 inch chopped off

Tested and pretty close

Sent from my SM-S911B using Tapatalk

Figures I keep seeing is more like 25-30fps per inch. And over the 3 rifles I own that is about the norm.

Obviously there is a point where it's short enough to show dramatic drops in difference but that seems to be calibre dependant.

The way I understand it, it depends on the cartridge volume/bore volume ratio. The greater the volume of the bore compared to the cartridge volume the less velocity you will loose per inch removed. ie, 308win will loose less than 7mm08 will loose less than 243win etc (all other things being equal).

18 in barrel not as noisy as 16in.

Originally Posted by HNTMAD

Rule of thumb is 50 fps per 1 inch chopped off

Tested and pretty close

Sent from my SM-S911B using Tapatalk

As above,iv had several tikas of different barrel lengths over the yrs in 308.With factory Hornady Superformance 165gr you loose about 50ft/s per inch of barrel length chop.

20 inch barrel
165gn SST = 2750fps

16inch barrel, same rifle
165gn SST = 2570fps - loss of 180fps, 45fps per inch
125gn Nosler BT = 3010 fps

I often use my 15 inch 308 and DPT

150g NBT@ 2730fps

I have a 22 inch barrelled BSA in .308 and get 2810 fps with AR2208 and 150 grain bullets. If I leaned on it I can get 2900 fps. I dont use a supressor and have the best hearing out of anyone I know. I can hear you reading this right now. I dont know why the shooting hasnt affected me. I wear ear protection at the range but not when I am hunting.

Hearing in my left ear is at 50%

Right ear is at 65%

I blame the 600 Mohawk in 308 and Kawekas venison tops Sika on a Friday evening

BBTI - Ballistics by the Inch :: Home

If you reload there's a chance you can find a recipe to gain you back speed, if you really feel the need

Originally Posted by Rock river arms hunter

Yep.

Not suprised by the numbers.

Sounds like my 308 will be heading off for a barrel chop, half cock installed.

Cheers team!

Just make sure not to dock 4" off your other barrel,or you will indeed be spending the rest of your life half cocked

Im running 18” barrel 168 A-max not pushed very hard doing 2541fps. I’ve had a 16 before and don’t think the extra 2 inches is worth taking off . 18 in my opinion is perfect length.

Originally Posted by GSP HUNTER

..
Is 18 the happy medium for velocity and noise reduction. ...

I assume you mean shooting a naked barrel of that length? NO centrefire is acceptable without a can or ear protection unless you want to become a "deaf old bastard" who can't function in any background noise.. I'd say I fitted well over 1000 old shooters with hearing aids in my career. Ageing alone is bad enough for hearing without adding a helluva lot more to it from shooting.

Originally Posted by Micky Duck

Just make sure not to dock 4" off your other barrel,or you will indeed be spending the rest of your life half cocked

Assuming that it started at 8". By the law I think that it's actually unlawful concealed carry of a piss-tool...