New tc contender 375 jdj 23" ss bull barrel
Re-15 powder start 45.0 gr + .5 gr up to 49.5
Sierra 250 gr slugs. OAL set at recommended length
cci 200 primers
Rem 444 resized to 375 jdj
This is a single shot string from the starting powder charge to the upper end weight. The first 3 rounds were used to adjust impacts on to paper. Once on, I stopped adjusting the scope settings and shot the remaining rounds and took note of where each impact landed for a particular powder charge weight and also examined the fired round for excessive pressure signs.
Powder charge weights 48.0 and 48.5 were stacked on top of each other while others were walking around the paper. And there were no pressure signs up to the 49.5 gr weight. I then made 20 rounds using 48.0 gr charge weights and the first 4 rounds were used to adjust impacts top of point of aim. Rounds 5 and 6 made a ragged hole followed by round 7 which went 1" right and slightly lower than the ragged hole. I shot 5 more rounds but the grouping was starting to open up.
Next time out, I will continue to test the re-15 48.0 gr powder grouping from a clean bore. But I think I will stick to this method of checking for pressure signs and accuracy for my new custom 204 ruger barrels and a remington mod 721 I shipped out to get re barreled in 30/06.
The 375 jdj barrel was cleaned out after the pressure testing rounds. The 48.0 gr powder charge showed promise in its first group testing.