I see lots of data for Reloder 19 and 22 in 6mm Ackley, but none for IMR4831. Reloder 19 and 22 with the 105 grain Amax are at max around 52 grains. Would starting around 47 grains be safe with IMR4831 and 87 and 105 grain bullets?

Tyler, I assume you are asking about loads for the 6m/m Remington in the Ackley Improved version. Is that correct?

If so, then what I usually do to get a starting load for any "improved" cartridge is to look up the recommended loads for the "standrd" version (in this case the plain vanilla 6 m/m Remington) nd use the middle level loads listed for that standard cartridge. (That is, half way between listed minimum and maximum loads for the same bullet weight.) Has always worked with no problems for me, but of course YMMV.

Good luck,

AC

For the 87's...
IMR-4831 From 44.9 grains to 49.6 grains Remington 9-1/2 Primer

For the 105's...
IMR-4831 From 42.7 grains to 48.2 grains Remington 9-1/2 Primer