Boolit weight

[snipecg21]

I'm trying the lee C309-170 F For my 30-30. I cast these about a month ago. the alloy is 50/50 lyman #2 from rotometals and pure lead. After seating the gas checks i was weighing them and found they're all weighing 176.2 to 176.8 grains. As I'm trying to keep my velocity at about 1600 fps can I still use load data for a 173 grain boolit from Lymans cast bullet handbook or do i need to make changes to my alloy to reduce my weight or is there anything else i need to watch out for ? I'm still at the begining of the learning curve so any advise is appreciated.

[mdi]

Your alloy has more lead and probably heavier than the alloy used by the folks that tested for the manual. I'd use starting loads for the 173 gr. bullet, and work up to get the velocity you need...

[charlie b]

Just load and shoot. Do start with lower than max pressures, but, this is not usually an issue for most cast bullet loads. And, you will not be at the same velocities as the book powder levels. Not a big deal.

FWIW, Lee specs their molds for COWW alloy (unless something changed in the last 20 years :) ).

[bmortell]

being a bit heavier than advertised is normal, most of my molds are like that. usually you'd use data from whatever design is most similar and has crimp grove in the most similar spot that's close to the same weight. that's normally more appropriate than trying to match weight exactly because the one it matches weight to might be seated deeper and give a different case volume ect.