Posted: Tue Jan 01, 2008 12:11 pm
Yes, 13 grains seemed like a reasonable starting point - IIRC I first tried that because about 14 grains or so is what I had loaded in some of the slightly longer MkI cases with reasonable success. However, I found that in the shorter MkII case 13 grains was "overfilling" the case, to the extent that it was likely being compressed too much when the bullet was seated. (Using the hollowbase bullet, I was trying for enough powder to flow up into the base cavity, but didn't want any significant compression, because of Hodgdon's caution against that with Triple7 as liable to cause significant pressure increases. I've only recently begun using Triple7, but my understanding is that, ideally, loads should leave no airspace but also not be compressed to any significant degree ... which leaves a relatively narrow "window" to work in ...)
When I realized that the 13 gr. load was likely still too much, I adjusted the powder volume down to what looked like it was accomplishing my aim without significant compression - and that resulted in the volume of approx. 10 gr. You may have to adjust that a bit, depending on your bullet configuration and seating depth. I was leery of the 13 grain loads, but tried them anyway - the noticeably greater 'bark' and recoil confirmed (in my mind at least) that there was too much compression with that volume of powder.
When I realized that the 13 gr. load was likely still too much, I adjusted the powder volume down to what looked like it was accomplishing my aim without significant compression - and that resulted in the volume of approx. 10 gr. You may have to adjust that a bit, depending on your bullet configuration and seating depth. I was leery of the 13 grain loads, but tried them anyway - the noticeably greater 'bark' and recoil confirmed (in my mind at least) that there was too much compression with that volume of powder.
Good to see you on this board too as there is a lot of information you and the others share that is very helpful.