IMR SR4756 and SR4759
 

Anyone tried IMR SR 4759 or SR 4756 yet? the 6 is faster... but both are designed for large case pistol rounds and heavy pills. SR4759 is my favorite in the 308 with 240's, so I've got some it around, but not sure where to start in the 300 whisky tango foxtrot.

took a stab at it today with some test loads in SR 4759. 8.5" barrel, pistol port, pistol buffer (heavier than carbine) with an H buffer.

50 degrees, 65% humidity, shooting with the can on

IMR SR 4759
Hornady 225 BTHP
9.0gr 985.2 fps, 985.6 fps
9.5gr 1006fps the other rounds didn't read on the chrony

Neither cycled or ejected, but came close to ejecting. It sounded fairly quiet though, not trailboss quiet, but quiet.

I went to load a few with SR4759 last night and found that in my powder measure, it's too coarse to throw consistently in this small of a charge.... in fact it bridged a few times as I worked my way to the desired charge. I need to use a different method of throwing charges... trying to find a Hornady Auto-Charge that somebody no longer needs.

Check this out www.quick-measure.com claims to allieviate the problems your having.