Author: britrifles
Subject: A change of Scenery with upgrades...
Posted: February 28 2020 at 5:21am
Magnum primers will typically add energy to the load, equivalent to about 1 to 2 gr of additional powder and 50 to 100 fps additional MV of a typical .30 cal cartridge like the .303 and .308 as compared to the same load with standard primers. I think Goosic's load will be fine even with a magnum primer, Sierra tends to be fairly conservative with their .303 load data. I'm going from memory here, so I'll read what is says in my Sierra loading manual tonight.
Subject: A change of Scenery with upgrades...
Posted: February 28 2020 at 5:21am
Magnum primers will typically add energy to the load, equivalent to about 1 to 2 gr of additional powder and 50 to 100 fps additional MV of a typical .30 cal cartridge like the .303 and .308 as compared to the same load with standard primers. I think Goosic's load will be fine even with a magnum primer, Sierra tends to be fairly conservative with their .303 load data. I'm going from memory here, so I'll read what is says in my Sierra loading manual tonight.
It's tricky though, as loads approach (or exceed) maximum published data, velocities can suddenly jump considerably which indicates that the pressure curve has also changed considerably. I've found this myself chrono'ing my Re 15 loads.
I've also had good success in the .303 with IMR 3031. But it is a fairly fast burning powder giving higher peak pressures for the same velocities as compared to powders like 4064, 4895, Re 15 etc.