looking to try this powder during some load testing. Does anyone have any data? I really need a starting place. I'm loading for the Sierra 107 gr MK w/ a 30" 1-8 twist Lilja barrel. Thanks

Carverelli,

Retumbo is much to slow for the 6mm-284, even with the 30" pipe and heavy 107gr MK. I have tested powders from IMR-4350 up through H-1000 and found that RL-22 produced the highest velocity with the most acceptable pressure signs and case life.

The faster powders can get the same velocity pretty much but with much lower load density and usually higher extreme spreads and a bit less accuracy.

The slower powders run out of case capacity far to soon for good working pressures. They can tend to be accurate but often because of low pressure, they do not burn as cleanly as they should.

Choose a powder in the same class as Rl-22 and you will be very happy with the results. Retumbo would be a great powder for the 6mm-300 WSM but I suspect you wouldn't gain much over the 6mm-284 except a shorter barrel life.

Good Shooting!!

50

Fifty, glad to hear from you. Just starting load development. Dennis did some beautiful work for me. I had him install a muzzle break for me laso( which he made himself) and it works great. Muzzle flip is almost nonexistent. Haven't got a velocity readin yet though. I went out yesterday and only had one case that would chamber( should of checked them before I left!) Found out I need to turn the necks down another .002 Next weekend we will see. So far I've loaded up to 55 gr RL22 w/ some primer flattening. I was breaking in the barrel. Later this week my scope should be here also-8.5x25 Leupold LRT.