Re: Accuracy of your SBR 300 Blackouts
Posted: Sun Apr 16, 2017 8:30 am
Dellet, all that is likely true.
Shooting subs to 300 yards sounds fun, but it's also outside my personal parameters of accuracy requirements/work vs return.
I figure that for my uses (hunting and defense), the accuracy requirements for any load is about 2" out to the MPBR, assuming that the projectile will still perform at that velocity.
So, subs...I figure 75 yards with no come-ups, so 1.25" - 2" at 100 is fine.
Supers, perhaps 150 yards max with no come-ups.
Accuracy requirements flow from that, divided by the coefficient of lazy-ness.
I do load sub-MOA for my 308 bolt gun, but really it's academic I suppose. And as you alluded to, that rifle has a nightforce 4-14x56, and throws 168 amax's, so it's not really apples to apples.
I am interested in finding a short-cut powder that will meter well for subs, because hand trickling my training rounds is pretty inefficient.
(Edit)
So, I gave it another go with some magnification. Unfortunately that means I used a different rifle, and therefore a different barrel length.
Rifle:
16" AAC barrel
Trijicon ACOG TA31RCO-M150 (4x32)
Specwar 762
Geissele SSA
VLTOR A5H0 buffer
The rifle is zeroed for suppressed supersonics (125TNT) at 100y.
Same 168 grain subsonic load, though obviously at a higher velocity. If it's hot out and I get the chamber hot, some go supersonic.
The good news is that the illuminated crossbar is exactly the right holdover for this load at 100 yards.
The bad news is that the group size worse, +/- 2" center to center, but it's not really a fair comparison, as it's a different barrel, different velocity, etc.
Worse yet, the POI is 3" left. I don't mind holdover/vertical drop, but the L/R offset is a deal breaker.
Perhaps re-timing the mount to re-orient the suppressor could lessen this effect, or shift it more to the vertical plane, but it's my go-to supersonic rifle, and I don't really want to mess with it.
I like 300blk, both subs and supers, but in my experience, the premise of "switching from supers to subs with the change of a magazine" is somewhat overstated.
Though that's not really relevant to this discussion of overall accuracy.
What I ~can~ say with regards to SBR accuracy, is that with this particular load, MY 10.5" is more accurate than MY 16", given the advantage the 16" has with 4x magnification.
Now I might have to swap the optics and re-zero everything to satisfy my curiosity.
Shooting subs to 300 yards sounds fun, but it's also outside my personal parameters of accuracy requirements/work vs return.
I figure that for my uses (hunting and defense), the accuracy requirements for any load is about 2" out to the MPBR, assuming that the projectile will still perform at that velocity.
So, subs...I figure 75 yards with no come-ups, so 1.25" - 2" at 100 is fine.
Supers, perhaps 150 yards max with no come-ups.
Accuracy requirements flow from that, divided by the coefficient of lazy-ness.
I do load sub-MOA for my 308 bolt gun, but really it's academic I suppose. And as you alluded to, that rifle has a nightforce 4-14x56, and throws 168 amax's, so it's not really apples to apples.
I am interested in finding a short-cut powder that will meter well for subs, because hand trickling my training rounds is pretty inefficient.
(Edit)
So, I gave it another go with some magnification. Unfortunately that means I used a different rifle, and therefore a different barrel length.
Rifle:
16" AAC barrel
Trijicon ACOG TA31RCO-M150 (4x32)
Specwar 762
Geissele SSA
VLTOR A5H0 buffer
The rifle is zeroed for suppressed supersonics (125TNT) at 100y.
Same 168 grain subsonic load, though obviously at a higher velocity. If it's hot out and I get the chamber hot, some go supersonic.
The good news is that the illuminated crossbar is exactly the right holdover for this load at 100 yards.
The bad news is that the group size worse, +/- 2" center to center, but it's not really a fair comparison, as it's a different barrel, different velocity, etc.
Worse yet, the POI is 3" left. I don't mind holdover/vertical drop, but the L/R offset is a deal breaker.
Perhaps re-timing the mount to re-orient the suppressor could lessen this effect, or shift it more to the vertical plane, but it's my go-to supersonic rifle, and I don't really want to mess with it.
I like 300blk, both subs and supers, but in my experience, the premise of "switching from supers to subs with the change of a magazine" is somewhat overstated.
Though that's not really relevant to this discussion of overall accuracy.
What I ~can~ say with regards to SBR accuracy, is that with this particular load, MY 10.5" is more accurate than MY 16", given the advantage the 16" has with 4x magnification.
Now I might have to swap the optics and re-zero everything to satisfy my curiosity.