Velocity Loss from Shorter Barrel for .308

[jasonprox700]

I was wondering what the velocity loss would be from a 24" barrel to a 16"?  This would be a brush gun that would be used for deer.  Thought this would make for a nice & light carry gun for miles of walking.  Shots would be short.  I would be using either 180 or 165 gr bullets if that makes a difference.

[R.W.Dale]

I was wondering what the velocity loss would be from a 24" barrel to a 16"?  This would be a brush gun that would be used for deer.  Thought this would make for a nice & light carry gun for miles of walking.  Shots would be short.  I would be using either 180 or 165 gr bullets if that makes a difference.

 Typically it's much less than you think it would be. Inside 300yds there isn't a critter in the world that would be able to tell you used a 16" bbl

If you'll take things to extremes and compare reloading data for a 14" handgun vs a 24" rifle in 308  you'll find that there is no real reason to carry a rifle with a bbl longer than 18"

According to hodgon shooting a 150grn bullet with a max load of varget

308win

14" handgun 2675 FPS vs 2937 for a 24" rifle for a loss of 262FPS for 10" of barrel or 26fps per inch

[banen]

I can't say I ever chrono'ed it but I shoot a 20" .308.  I have never thought there would be a meaningful loss in the 308.  It is a pretty efficient cartridge.  The 308 is a great cartridge, go for it. 

[thumbcocker]

I have a remington 7600 with an 18.5 inch barrel. The only load that I chronographed so far was the remington 150 gr. load. Factory spec's says 2820 f.p.s. out of a 24 inch barrel. I got 2694 f.p.s. out of mine. When I get a chance I'll post what the 180's do. I ntend to use 180's anyway.

[Lone Star]

Comparing velocities out of different barrels is frought with error.  Even two different barrels of the same length will give different velocities - how do you know if the velocity difference between different length barrels is due to the length difference or to the normal difference?  To know for certain you must cut off the same barrel into different lengths and chronograph loads. 

From G&A 9/1987 with the .308, a 180 grain bullet and IMR4302 powder:
Length.....velocity
24"...........2700 fps
22"...........2660
20"...........2620
18.5"........2575
16"...........2480

G&A 7/1989., .308 and 165-grain Hornady factory load:
Length......velocity
22"............2674 fps
20"............2617
18.5".........2598

The average velocity loss from a 22" barrel to an 18.5" barrel was 81 fps.



.

[AtlLaw]

From G&A 9/1987 wtih the .308, a 180 grain bullet and IMR4302 powder:
G&A 7/1989., .308 and 165-grain Hornady factory load:

The average velocity loss from a 22" barrel to an 18.5" barrel was 81 fps.

Thanks LS!  I was thinking about these articles last night but in no way could I rember where I read them or the results in more then general terms!     I was answering a post in Bolt Action Rifles where the OP asked about the effect of action length on velocity...    I know, don't say it.     I'm gonna try to post him a link to this thread.

[Graybeard]

I am one who likes short and handy rifles as most of my shooting is at fairly close ranges in the thick woods here. Still I do think there is such a thing as too short at least for me and I kinda draw the line at the 18" range. For me a rifle with 16" barrel just feels too short.

I'd not worry over the velocity loss. Really if velocity is a concern then the .308 isn't the best choice to begin with but for a rifle with less than full length barrel it's a great choice. Just forget the velocity loss and know that what velocity is left is more than adequate for the task.

[BBF]

The other thing to consider is that for any given cartridge the heavier bullet will loose less velocity per inch then the lighter types. I would suggest a 180 gr RN or if the range is very short you could even try a 170 gr (30-30 type bullet) with reduced loads.

I have a 30-06 pump carbine( 18 1/2) barrel that shoots the 150 gr. Rem RN at about Sav. 300 velocities very accurate and is a pleasure to shoot.