7mm RUM/180gr Berger Disappointment
Spent the money for the 180gr Bergers a couple of weeks ago and have been working up a load. I'd really like to take advantage of the high bc of these bullets, and I've never heard a dissenting opinion of Berger bullets in general. Upon the advice of Carlock and others I tried Retumbo and US869. I laddered both of those powders and found that US 869 gave significantly higher velocities than Retumbo, up to almost 3200fps before the cases showed signs of pressure. The ladders showed some sweet spots, but because of the higher velocities I got with the 869 I decided to try loading some test rounds with that powder. I loaded 5 rounds each at 99, 101, 102grs respectively. Groups started out at almost 2" and went up from there. I only fired three rounds at the 102gr level before I gave up. To say I'm very disappointed in the Bergers would be an understatement. I thought I had everything set correctly, including seating them almost two thousands into the lands. I know it's not me as I can hold 3 160gr Accubonds inside 1/3" at 100 yards with that rifle. What did I do wrong? The only thing I can think is that the twist rate is not fast enough in this bbl to stabilize that heavy of a bullet. Has anybody had any luck with these bullets in a factory 26" bbl? How about the 168gr Bergers or Sierras? Any advice would be much appreciated.