.300BO W/ 220gr platted Berry's, 10.5" AR 15, 2 choices:

Cannonman · Mar 16, 2021

Hi guys. I've Got Winchester ball powder 296 and IMR 4198. For a .300 BO loading Berry's platted 22gr in a 10.5" AR 15. Anyone got load data?

Cannonman · Mar 16, 2021

Oh, and I want to be just under supersonic. Thanks

osprey · Mar 16, 2021

H110/W296 is a great supersonic powder in 300blk but has a sketchy reputation for subs. Of the two I would try the imr4198 as I have seen more successful.sub loads using it. You will probably end up somewhere between 10 and 11 gr. to reach sub velocities. Whether or not it cycles properly in your specific rig will be somewhat of a wild card. Remember, start higher and work lower with subs. I would start at 11.5-12gr and work down.

Cannonman · Mar 17, 2021

Hey Osprey! Thanks! First loads, from reforming brass to shooting and you were spot on!

osprey · Mar 17, 2021

Cannonman said:
Hey Osprey! Thanks! First loads, from reforming brass to shooting and you were spot on!

Glad to help. Did they cycle your gun?

Cannonman · Mar 20, 2021

Gun did cycle, targets were hit! I remember the first reload I did some 25 years ago for a 92FS. It went bang, the bottle broke and I was hooked! Thanks! Just got two new jet skis yesterday but there's a 2 MPH wind so I think I better side on caution and do some more .300 reloads. SAFETY FIRST!