Got a Labradar now. The below loads were launched through a BRT Optimum Light barrel. 16”, melonite, 4150, 5r, 1/8, A2 flash suppressor. Has ~5,000 rounds on it at this time. All were a sample of 10, unless noted. Temp was 49F. Military ammo is real, not XM or whatever. Velocities are at muzzle.
*M855
5rnds
Av 2805 fps
ES 59
Std Dev 25
With Griffin M4SDk
Av 2880
Es 58
Sd 28.9
This is a +75 fps with the can.
*M855a1
5rds
Av 2893
Es 65
Sd 25.3
This is 88 fps hotter than M855
*“Brown Tip” 5.56 70 TSX
Av 2719
Es 47
Sd 15.1
*Hornady Frontier 68gr 5.56
Av 2719
Es 41
Sd 15.2
Notice this velocity is essentially equal to the 70gr mil load above.
With the can
Av 2727
Es 50
Sd 22.7
Seems that this bullet gets less freebore boost than the lighter rounds. Maybe its the weight, or the boattail form? +8fps
*Precision One 62 gr
Av 2439
Es 200
Sd 68.6
I failed to record whether this was new or reman and whether it was 5.56 or .223. Looks like .223, obviously. One round failed to cycle the H3 and Sprinco Blue.
With the can
Av 2534
Es 115
Sd 37.5
Thats +95 Fps with the can, and it cleaned up the consistency somehow. Hell yeah.
*62gr Hornady FMJ on top of 27gr Cfe223, LC brass
Av 2838
Es 150
Sd 41.6
Done on a Dillon 750, letting the powder drop do its thing. Light crimp, cannelured bullet.
*24gr Cfe223
Av 2314
Es 260
Sd 78.4
This stuff actually cycled the gun everytime, unsuppressed, and locked back on the last one. Gun has an H3 and Sprinco Blue.
Bought some more Precision One to see if day one was a fluke, and brought out more ammo, as well. Same gun, same silencer, 42*F and raining.
*Precision One new manufacture 5.56 62gr non-magnetic
Av 2303
ES 312
Sd 89.7
With the can
Av 2373
Es 249
Sd 78.9
First day was not a fluke. This is a starting load, I guess. I’ve never had any problems with it, but I’ve never shot it past 100, either.
*Barnes Vor-Tx 70gr 5.56
Av 2730
Es 67
Sd 20.8
A little hotter than “Brown Tip” and a little less consistent. Plenty good enough for pork.
With the can
Av 2718
Es 63
Sd 17.6
WTF? Lost an insignificant amount of velocity.
*Fusion MSR
Av 2666
Es 178
Sd 55.5
With the can
Av 2675
Es 190
Sd 61.1
So only 9 fps boost, which is not statistically significant. And its a little further behind the Barnes Vor-Tx 70 gr 5.56 than I thought.
I’ll do some more another day, maybe some other barrels. Might do some less lethal, for S&G.
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