I have a 10" scoped to a VXII, have used both RCBS and Lyman bullets-I cast my own.
RCBS- 32-098-SWC P/N: 082061
Lyman- 115 grain 311008 #2660008
This RCBS has turned out to be easiest to use, simply because of it's weight. The Contender likes light bullets for flatter trajectories. I used the Lyman #008 to start with and switched to the RCBS. The Lyman takes an extra 1/10th grain of 2400 magnum powder. It also takes an extra inch of elevation to lob it up there to 100 meters. Load tests are from sandbags.
My barrel is a used silhouette barrel, had jacketed ran through it maybe. It measures .310 and I started out with a sizing die to .311, I have .314 and don't use it-ain't broke, don't fix it.
With ordinary wheelweight and a Lyman sizer, it's possible to size these down. I use oil and/or ground mica to start the operation. Whatever doesn't wreck my sizer, maybe a stiff shove to make them work. But that wheelweight isn't hardened anyway.
In the event you can't see the photos, I am using 7.2 grains of 2400 behind the RCBS and 7.3 grains of 2400 behind the Lyman, Starline brass, winchester primers.