Short(er) Barrel .308/7.62 Chrono Results

**ST911** · 10-21-12, 21:15

Popularity of shorter-barreled 308/7.62 AR types and sport-utility/fighting bolt guns is on the rise. As users contemplate the external and terminal ballistics of loads for those guns, they find that most manufacturer data is built around ~24” barrels.

The following information is posted to add to the knowledge body and serve as a reference for future inquiries on the topic. As additional loads are chronographed, they will be added to this thread.

Unless otherwise specifically noted, content by me is chronographed on a Shooting Chrony Beta, ~15ft from the muzzle, five rounds fired.

MPV=Manufacturer published velocity
L= Low
H= High
A= Average
ES= Extreme Spread
SD= Standard Deviation

10/21/2012
Ruger Model M77 Mk II, 16” barrel, 1/10 Twist

Federal 150gr JSP (Power-Shok), p/n 308A
MPV: 2820
L: 2617
H: 2681
A: 2643
ES: 63.79
SD: 24.02

Federal Gold Medal Match, 168gr SMK BTHP, p/n GM308M (4 ROUNDS FIRED)
MPV: 2650
L: 2507
H: 2528
A: 2518
ES: 21.48
SD: 11.04

Remington UMC 150gr FMJ, p/n L308W4
MPV: 2820
L: 2517
H: 2698
A: 2596
ES: 180.7
SD: 67.79

Winchester 147 FMJ, p/n Q3130 (also USA3081)
MPV: 2800
L: 2607
H: 2716
A: 2657
ES: 109.4
SD: 43.28

Herters 150gr FMJ, p/n IK-217668
MPV: 2800
L: 2463
H: 2543
A: 2516
ES: 80.75
SD: 32.32

I’ll be adding some additional loads as shooting sessions follow, including some of the premium purpose-built defensive loads.

**ALCOAR** · 10-21-12, 22:07

Thank you, good data points.

I'm a big believer in a 16" .308

**ST911** · 10-21-12, 22:17

Originally Posted by TRIDENT82

Thank you, good data points.

I'm a big believer in a 16" .308

Me too. My primary bolt gun has been a 16" 308 for the past several years, shooting a lot of the 308A and 155 AMAXs. Velocity and trajectory is the easy part though. Thresholds of bullet performance are more elusive.

**S. Galbraith** · 10-21-12, 22:19

I chronoed the Hornady 168gr A-MAX out of a 16" LaRue Predatar. 2476fps average from a 10-shot group. Manufacturer's velocity from a 24" barrel was 2700fps.

**SPQR476** · 10-21-12, 23:23

12.7" G3k clone

Radway 147 ball= 2460 avg 5
SA ball = 2425 avg 5

**tdb59** · 10-22-12, 12:18

Originally Posted by S. Galbraith

I chronoed the Hornady 168gr A-MAX out of a 16" LaRue Predatar. 2476fps average from a 10-shot group. Manufacturer's velocity from a 24" barrel was 2700fps.

The rule of thumb for presumed velocity change in centerfire rifles has been 25-30 fps per inch since before the innerweb.
This seems to be proving out by the data posted.
Thanks for your effort !

**2theXtreme** · 11-07-12, 16:23

I am just getting into 308s and midrange shooting and I have a few questions. I was going to start a new thread until i found this one. Hopefully this is an appropriate place. What would be the maximum distance a 308/762 would remain accurate (in regards to a human body) and lethal coming out of a 14.5" barrel? Also, what 308/762 round is the equivalent to the 556 M855 or M193? Thanks for any help I can get!

Sent from my iPhone 4 using Tapatalk

**RD62** · 11-21-12, 20:29

The data below was collected from my 18" Stainless barreled LMT MWS in 10rnd strings (except for the Privi where there's a round missing?) using a ProChrono Digital approximately 6' from the muzzle.

I hope it is useful to some.

**ALCOAR** · 11-21-12, 21:47

Given the relatively recent movement towards 16" .308 ARs, any velocity data based on 10 rd strings using popular/abundant factory loads through them will be quite valuable. Thanks for going to the effort of organizing it so well as well.

My GMM strings mirror yours almost exactly. Same thing with your Amax numbers. (ES/SD wise). As I've stated before, FGMM 168gr. SMK through the 16" CL is really amazing in terms of precision, however outside of the Federal Fusion 165gr. load....it, and the 175gr. SMK variety pack easily the most recoil for any factory load I've shot out of 15-20 different types.

I was gonna try and go today to do nothing but chrono work including some with my MWS 16", but the damn day doesn't last this time a year.

Hopefully if the OP approves, I'll add quite a bit of velocity data that I already have, and will be gathering in the future to this thread.