Thread: 284 Winchester load data using AR2209

Originally Posted by Boomdog

I am using hornday 139g interlocks with 57g AR2209 no pressure signs out of a 16 inch barrel

Greetings again @Boomdog,
You are unlikely to see any of the commonly quoted pressure signs until you are well over max pressures. Hodgdon does list 57 grains of H4350 (AR2209) with the 139 grain SST for 3,079 fps. This projectile is reasonably close to the Interlock you are using. It is loaded to 74mm (2.915") overall length and as the pressures are in the now obsolete CUP my concern would be that this data is for the older and slower AR2209. Hodgdon quotes a velocity of 3,079 fps in a 24" barrel but yours is 8" shorter so you would lose between 200 and 250 fps or 2,800 to 2,850 fps in your barrel. For your and your rifles safety your load needs to be chronographed. A combination of a shorter throat and faster powder could have put you well over the limit. Please feel free to ask questions.
Regards Grandpamac.