A while back me & a buddy run the chrono on some ammo I had laying around. Some of the ammo used is hard to get civie wise, and there’s not a lot of numbers out there for the SCAR 17 CQC, so I hope this helps. Theseare 10 shot averages unless otherwise noted.
SCAR 17s 13" barrel:
Real issued Mk 316 (175grSMK)
2339 fps
5 shot average as I have a limited supply
White box Mk 319 from Palmetto State (130 gr SOST)
2672 fps
This number somewhat puts the whole “Ak/300 Blackout Ballistics” into perspective. Also flash & muzzle blast with this load is IMHO not as bad as M193 from a 10" 556. I am also happy with this load’s performance through steel. Even from this barrel length at 100 yds it will cut through AR400 boiler plate. Other .308 loads I’ve tried will not.
Hornady 155 gr TAP-FPD
2424 fps
Federal 168 gr GMM
2321 FPS
5.56mm from 10" SCAR 16
M855
2642 FPS
Black Hills Blue Box 75 gr Match
2243 fps
Federal 77 gr GMM
2197 fps
Real Issue 5.56mm Enhanced “Brown Tip” 70 gr Barnes
2467 fps
Mk 318 62 gr SOST
2539 fps
Wolf 62 gr
2469 fps
I’ll try to get more common ammo chrono’d when time allows.
Thanks for all the great info. The SOST 7.62N load looks impressive, how are reports from the field? How is the recoil? In the NDIA presentation they mention it is optimized for relatively short barrels (16" or so) and it has “reduced recoil”.
Edited to add: the NDIA presentation mentions a 2750 fps velocity (measured with the skyscreens at 15’) for the 13" SCAR Mk 17 barrel.
All I can speak for is recoil, which is a very subjective…subject:) It is a very soft shooting load in my SCAR (to me). Infact, the only load I’ve fired thusfar that stood out as “wow, that was hot” is the Hornady 178 gr Superformance. With deer season coming up, I hope to try out the Mk 319 a little more that I did last year. One thing I noticed about the Mk 318 & 319 out of both SBR’s is a very low muzzle flash compared to other loads at night.
Just a few numbers on muzzle energy:
319: 2062 ft lbs ~85% of normal
318: 887 ft lbs ~70% of normal
Its interesting that the 319 has ~2000 ft lbs, which is right at the top end of the energy range proposed by many for an “ideal intermediate cartridge” that balances recoil and down range performance.
1/4 or 5/16? I can’t remember, some I had left over from a boiler ID fan repair. I shot it with various 556 & 762 loads. The Mk 319 was the only thing to penetrate it. The German DAG put a serious dent in it, but didn’t go through. The Mk319 would penetrate every round fired & would also go through a piece of 4x4 lumber I proped it up with.
Just in what little I’ve seen, I’ll be this round would be good medicine for vehicles.
I have access to a 16" SCAR 17 & when time allows I’ll try to get some #'s off it was well.
As far as accuracy with the Mk 318 & 319, Its odd as almost every 10 shot group I have fired with it from pretty much any rifle gives 6-7 really tight shots & a few flyers. I’m 99% certain it’s not something I’m doing. I know others have seen this as well.
It’s the bullets with the 319. I’ve loaded a bunch of pulls. If you sort them for weight and OAL you can cut down on the fliers quite a bit, but despite their designation they are NOT match grade. It doesn’t really matter for what they’re intended for, though. I like them out of my 16" SCAR.