Originally Posted by phorwath
I sized down in one step and then expanded the neck with the K&M Services mandrel and outside neck turned. Then annealed the case necks.
The only powder I've used is US869, and the only bullet I've used is a Berger 115gr VLD. The fastest load was ~3900 fps but that was too hot - pressure wise. 3700 fps is more realistic with the 115 VLD bullet and 96-98 grains of US869.
I stopped playing with the 115gr Bergers because I had two bullets fail to reach the 300 yd target. The Bergers must be coming unglued in the bore or in-flight at these MVs. After that I decided there was no sense in wasting barrel life with the VLDs. I'm waiting for Wildcat Bullets to start shipping bullets and then I want to try their 130gr RBBTs and see if they'll stabilize in my 1:10 twist barrel.
I'll be surprised if I get 600 rnds of barrel life. But I did Gun Juice this bore.
This will be a good test barrel to see if the Juice prolongs throat life. Once this barrel is toast, I'll probably reduce the horsepower. Haven't decided which cartridge yet.
After my recent experience of getting 3200 fps with a 180 bullet in a 24" 300 WSM with 67.5 grs of RL17, I am wondering how advantageous it would be to get 3400 fps with ~ 100 grs of powder out of a 26" 300 RUM? Which also makes me wonder how close an overbore WSM wild cat might come to the RUM wildcat?
I'll shoot out out my 300 RUM and then I might rechamber to a .338 or 300 Dakota or WSM, unless Alliant or someone else comes up with a slower burning version of RL17 for the larger mags.