I was hanging out with Charlie Sisk doing some load development in his private indoor range a few weeks back, and we stumbled across a pretty surprisingly accurate subsonic .243 Winchester load. We were trying to find an acceptably accurate load for one of his friend’s kids to start practicing without much recoil or noise (they have a silencer), and after some trial and error we were getting as good a group as if we’s been shooting supersonic. Here’s the data . . .
Brass: .243 R-P New
Powder: Trail Boss 12.1gr
Primer: Federal 210
Bullet: Nosler 70gr Ballistic Tip
COL: 2.610
Barrel twist: 1:10
As for how well it groups? Check out this 100 yard target:
That’s 10 rounds through the same hole, ignoring the one flier, at 100 yards. We could see daylight through the other side.
Since Charlie was super pumped about this load, I figured it was worth sharing. Good luck, and happy loading!