Non cast bullet content - My loads with 5744 started to give larger groups at 2100 fps with 200 grain powder coated bullets. I suspect alloy failure as the velocity and pressure exceeded the ductile strength of the alloy
I am getting some plastic shot buffer for case filler from a friend later today and I will see if I can not get more velocity out of the cast 200 grain powder coated using a filler
I finally got some Sierra 200 grain 0.375" and swaged them to 0.367" - abusing the NOE bushing in my NOE cast bullet sizing die. Found a load for IMR 4064 for 358 Winchester of 49 grains compressed for a 200 grain bullet giving a velocity of about 2500 fps in a 358 rifle.
I decided that this would be a good starting load for my swaged bullets and loaded up 10.
At the range, no signs of pressure, primers are still rounded and no signs of case expansion
Velocity was 2260 average for 10 shots and group size was 1" at 50 meters That is about all I am capable of with 70 year old eyes and worn out muscles with any gun.
I hope to work this load up to 2500 fps in the 9.3x57 but there may not be enough case to allow me to do this with IMR 4064.
It is really too bad that the bullet manufacturers do not offer a 200 grain soft point in 0.366" or 0.367" .
The load was from 358 Winchester data for 200 grain bullets published by Hodgdon in their on line loading data.