Home Forums Hunting & Shooting Ask The Gunwriters 280 Ackley SAAMI vs. 280 Improv 40 deg pre-SAAMI

I just did a bit of figuring with Hodgdon's 280 data for a 140 grain Partition.

H4350 is reported in CUP, so I extrapolated to 54000 CUP which is a usual pressure for 300 Weatherby. This gave an estimate of 3054 fps for the extrapolated max in the 280.

A similar calc for IMR4451 at 65000 PSI estimates 3059 fps.

Of course grain of salt and Danger Will Robinson, yadda yadda.