Some powders are very position sensitive. Trying Accurate 9 in my 30-30, I had a large difference in MV with the powder at the front of the case vs. the rear. Other powders do not have this problem. TiteGroup and 5744 are two that I have tested that do not have this problem, so far as I can tell.
Hodgdon's instructions for Trail Boss are to mark a case with where the base of the bullet will be, fill the case to there, and weigh the powder. That is a safe maximum load. Multiply this weight by .7, and you have a safe minimum load. Since your case is "reasonably" full, you should not have the position sensitivity problem.
In my 30-30 it only takes 12 grains of Trail Boss to fill the case. A jar of TB is only 9 ounces, and that is all that will fit in the jar.
Brownell showed a huge increase in pressure variability below about 30 KPSI in the 30-06. The scary thing is that he was using 4064 or 3031 if I remember correctly. The SEE problem is well known with 4831, but I suspect it is not unique to really slow burning powders.
Last edited by denton; 12/10/09.
