Hello All, I am Brennan, 24, Located near Denver Colorado. My good friend is a gunsmith, helped me build a custom 300 RUM. Been lurking on the site for a little while trying to get info about building loads. I have been shooting for a few years, reloading for a few years, 1st time with big mangum catridges. Uploaded with ImageShack.us Uploaded with ImageShack.us Uploaded with ImageShack.us Here is my build. HS precision Stock 700 SS lapped/trued. Holland Recoil lug Krieger 26" 11.25 Twist SS barrell. Seekins precision mag/bottom metal badger ordanance bolt knob. Timney 510 trigger ( not installed yet) Vortex 6-24 Viper PST Mil-rad scope Load: Berger 210VLD Winchester Primer Nosler Custom Brass US-869 powder. 3.730 COAL Seems to be a solid 1/2 MOA or better gun. Accuracy is good not sure if I want to seek more velocity My findings with 210vld and US-869 ( very slow and forgiving) 99.00 GR= 2950 FPS 99.5 GR= 2980 FPS 100.00 GR= 3030 FPS This is a new barreland velocity mayspeed up as barrel wears/breaks in fully. Little bit of copper fouling, not sure if its of concern but it shoots dandy.