16” 308 Match Ammo Gas Gun Velocities

[mcdougall53012]

Struggled to find popular 308 win Match loading velocities in a 16 inch gasser, so here’s a day’s worth of data collection.

Hornady 168 Amax Black: 2505 u / 2527 s
Federal GMM 168 SMK: 2425 u / 2425 s
FGMM 175 SMK: 2414 u / 2441 s
FGMM 185 Berger Jug: 2440 u / 2441 s
IMI 175 OTM: 2257 u / 2325 s

Federal Trophy Copper 165: 2555 u / 2564 s
Federal Trophy Bonded 165: 2604 u / 2606s
Federal Fusion 150: 2659 u / 2675 s

Test gun:
16” Chrome Lined 308 1/10 LMT MWS
Chrono: Labradar
Atmospherics: 51* F, 243’ elevation, 29.5hg
Unsuppressed (u): Area 419 H Match Brake
Suppressed (s): KGM R30

5 shot groups taken 1-2 minutes apart with bolt locked to rear for cooling. 100 yards

 

[mcdougall53012]

Groupings conclusions:
Hornady 168 Amax grouped well suppressed with decent velocity and BC. Excellent choice for precision and hunting.

Federal Gold Medal Match:
168’s and 175’s grouped similar with an edge to 175’s. 185’s had excellent velocity and SD’s but lackluster groups.

Federal hunting: Trophy Bonded and Copper had great velocity but poor groupings out of this test gun. 150 fusion had slightly better performance suppressed.

Accuracy considerations:
Chrome lined barrel, 4.5lbs trigger, 1-10 optic, and grouping fatigue. Unsuppressed groups were shot first followed by suppressed groupings. All match loadings had a sub MOA POI shift from any other match loading in this test.

 

[sinister]

Very close to mine at 2450-ish out of two 16-inch Criterions (one medium, one hybrid taper) shooting Sierra 168s and 175s.

 

[MikeMiller]

I have shot four 16” for velocity tests with same lot of Federal 175’s
1. Wilson Combat 2450 aver
2/3 LaRue OBRs. Both 2450 average
4. Savage MSR10 barrel 2500 fps.

Same ammo shot 2600 fps average from 20” GAP Bartlein bolt
all with low round count.

I dialed the gas way down in the savage hence the faster speed. The other three barrrls are fixed gas and way over gassed

The LaRues shot the ammo the best

 

[ToKeepAndBear]

Thanks McD! I just picked up a 16” 308 CL barrel for my LMT (have a 20” SS already). I just installed a BRT gas tube for full time suppressed use. Your post gives me a lot of direction as far as load development and MV! Thank you!

 

[ToKeepAndBear]

Those are pretty good groups for a chrome lined barrel!

 

[mcdougall53012]

Those are pretty good groups for a chrome lined barrel!

Can’t wait to install a Triggertech Diamond. A bit more break in and magnification should make this thing lights out

 

[Conrad101st]

My 16 inch LMT MWS CL barrel shoots 168 way better than 175.

FGMM was at 2512 FPS.
Noticed about a 1 inch poi change between suppressed vs not with that load.

The black AMAX 168 had almost zero change in impact point with can on or off. So it’s what I’m going to use. Have not chronographed it yet but was curious to see it was substantially faster in your weapon than the FGMM.

The 168 loads both grouped about 3/4 inch. 175 was about double that. I do not shoot past 600 with that weapon so no worries.

 

[Pappasniper]

My MWS tends to like 168's more than 175's but I should do more testing. It really love Hornady TAP but only bought 200 rounds and that is about gone. I'm going to start doing velocity testing with/ without a can. A good MWS CL barrel can really shoot excellent groups if you get a good one. And none are terrible in my experience.

Please clarify, is that what he showed in the OP u/s fps? ( Surprised / Unsuppressed) ?

PB

 

[Conrad101st]

My take of his abbreviation was:

U = unsuppressed
S = suppressed

 

[strikeeagle1]

A 2012 LaRue 16" suppressed.
Here's some numbers for Lake City XM118LR 175gr. ; 2483 fps. average. MagnetoSpeed V3 (haven't clocked it with my LR yet).
I use 175's mostly; 800M target. Hornady A-Max 168's @ 500M...The 168's generally become unstable past 600 meters, key holes on the target @ 700M.
Gorrilla 175 SMK and Applied Ballistics Berger 175 OTM Tactical are two good choices as well.

 

[mudholestomper]

Any rough extrapolations for 308 from an 18” barrel?

 

[mcdougall53012]

Any rough extrapolations for 308 from an 18” barrel?

+40-50 fps
308 is usually a 20-25 fps jump per inch

 

[mudholestomper]

+40-50 fps
308 is usually a 20-25 fps jump per inch

Thank you.