Hi....quick reload question...trying to work out appropriate MEC bushing size / rule of thumb guide when converting a Red Dot recommendation to a Promo load. I realise that Promo is denser & so should use a lower bushing number...is peoples experience to go 1 bushing size lower or 2?

For example if the RED Dot / promo powder requirement is 18.5 grains, MEC's recommended bushing size for red dot is #31...where would you start at for 18.5 grains of Promo ...#30 or #29? I realise I will need to measure etc, but am looking for general guidance so I can at least start in the right ball park.

Thanks for your help.

David

29 or 30. Impossible to say since Promo varies. Pick one...weight it...go from there. Not the answer you were looking for Im sure.......but thats the way to do it.

It's been my experience that Promo takes a full two sizes (at least) smaller bush for any given weight of RedDot. Not an equation I'd trust w/out a good scale tho. If you're under the max by a fair margin it might be OK but I'd just have to weigh it myself. I mean, I don't even trust the book info 'cept as a starting point.

What mikkeeh says every batch (lot number) has to be checked with a scale. I've tried some from several different lot #s sometimes they varied 2 or 3 bushing sizes, but they all chrono'd very close with weighed charges. Usually use 700X and that even varies slightly but not enough to have to change bushings every time you open a new container. Ross Puls

You need a good powder scale, suggest a digital around a $100 to get the exact results w/o guessing.

Gary Bryant Dr.longshot

Thanks for the ingo...I have a good powder scale...will start with the #30 (as that's what's in my machine) & go from there. David