This is what i've got:Hodgdon Retumbo and Sierra HPBT MK's 200 gr. in a 300 WinMag. I searched Hodgdons' website and noticed they were using Nosler Partition 200gr as opposed to what i've got.They suggested 84.0c grains,even though im using Sierra,can i still use the same grain amount?? Thanks

Retumbo From 79.0 grains to 84.0 grains
Winchester WLR Primer

So even though the bullet tail changes slightly in shape from one manufacturer to another,the grain amount is still the same? I would think it would affect the compression ??! Please correct me if my thinking is incorrect.

Considering that you are always supposed to start low and work-up gradually, it makes no difference.

Now, if you are gonna jump-in head first, without doing a proper work-up, right at the max. loads, it could make a difference...

OK thank you very much.now i can get busy