Danus ex
06-06-20, 15:26
When you Google this question, many people have asked, and even more people provided utterly worthless answers. The whole point of .300 Blackout is the ability to switch from short-ranged indoor suppressed/subsonic shooting to outdoor combat-distance suppressed supersonic shooting with a magazine change out of an SBR.
After a decade in use, I expected to find an answer as simple as:
"With an 8-10" barrel .300 Blackout SBR,
zero your red dot at ____ yards with 110–147gr supersonic,
and you'll be zeroed at approximately ____ yards with 200–220gr subsonic."
I've found indefinite hints online that it's either 200 super/50 subsonic or 200 super/100 subsonic. An old, failed Leupold reticle suggests 200/50, which I hope is true. Obviously, individual loadings will make a difference to the exact yard.
Other notes:
Most ballistic data was collected from 16" barrels, which misses the point of this cartridge altogether. Reminds me of government standards!
Many people attempt to find a zero distance that allows them to hit the same target at the same distance with both supers and subs. Others do the same with holdovers (15 MOA reported). This again misses the point, but does help those confined to <100 yard ranges.
Ballistic calculators aren't designed for this problem. They assume a static zero point, and those that allow a 0 zero/0 sight height (so, drop only) can't compensate for the upward angle a real supersonic zero would have on the subsonic round.
So, for .300 Blackout users, what's the real deal with super/sub zero?
After a decade in use, I expected to find an answer as simple as:
"With an 8-10" barrel .300 Blackout SBR,
zero your red dot at ____ yards with 110–147gr supersonic,
and you'll be zeroed at approximately ____ yards with 200–220gr subsonic."
I've found indefinite hints online that it's either 200 super/50 subsonic or 200 super/100 subsonic. An old, failed Leupold reticle suggests 200/50, which I hope is true. Obviously, individual loadings will make a difference to the exact yard.
Other notes:
Most ballistic data was collected from 16" barrels, which misses the point of this cartridge altogether. Reminds me of government standards!
Many people attempt to find a zero distance that allows them to hit the same target at the same distance with both supers and subs. Others do the same with holdovers (15 MOA reported). This again misses the point, but does help those confined to <100 yard ranges.
Ballistic calculators aren't designed for this problem. They assume a static zero point, and those that allow a 0 zero/0 sight height (so, drop only) can't compensate for the upward angle a real supersonic zero would have on the subsonic round.
So, for .300 Blackout users, what's the real deal with super/sub zero?