rickomatic
02-01-2009, 09:38 PM
OK. I've been reading Richard Lee's 2nd Edition, Chapter 10, "Matching Bullet Metal to Chamber Pressure".
I checked the hardness of my boolits with the Lee hardness tester, and came up with a metal strength derived off his Maximum Pressue Chart. I then took that info and applied it to the formula for finding a maximum charge for that metal strength using the pressure factor in his load tables. So far so good.
Here is where I'm a bit foggy.
1. do I use the total weight of my cast boolits (boolit + gas check + lube) as my projectile weight? My Lee C309-150F comes out to right at 157 gr once the gas checks are on and they are tumble lubed.
2. The load tables show recipes for 150 and 170 boolits with my chosen powder (H-335), and the attendent pressure figures I came up with, but nothing for 157 total weight.
So, do I use a little "averaging" and come up with figures that should be close for that actual weight?
and 3. Since his pressure factor/bullet strength is based off of maximum pressure loads in the table, should I use commonly held standards of reducing that load by 10% and working it up?
Howabout it boys...am I on the right track? Or am I over engineering this? :???:
Oh...one other quick question. When he talks about his "reduction rules 1 & 2" in that chapter he says to "never reduce the slowest powder more than 20%....and so on." When he says "THE SLOWEST POWDER" is he referring to the slowest powder in HIS chart? For reference, it's listed on pages156-157 of the Lee 2nd addition.
Thanks guys.
I checked the hardness of my boolits with the Lee hardness tester, and came up with a metal strength derived off his Maximum Pressue Chart. I then took that info and applied it to the formula for finding a maximum charge for that metal strength using the pressure factor in his load tables. So far so good.
Here is where I'm a bit foggy.
1. do I use the total weight of my cast boolits (boolit + gas check + lube) as my projectile weight? My Lee C309-150F comes out to right at 157 gr once the gas checks are on and they are tumble lubed.
2. The load tables show recipes for 150 and 170 boolits with my chosen powder (H-335), and the attendent pressure figures I came up with, but nothing for 157 total weight.
So, do I use a little "averaging" and come up with figures that should be close for that actual weight?
and 3. Since his pressure factor/bullet strength is based off of maximum pressure loads in the table, should I use commonly held standards of reducing that load by 10% and working it up?
Howabout it boys...am I on the right track? Or am I over engineering this? :???:
Oh...one other quick question. When he talks about his "reduction rules 1 & 2" in that chapter he says to "never reduce the slowest powder more than 20%....and so on." When he says "THE SLOWEST POWDER" is he referring to the slowest powder in HIS chart? For reference, it's listed on pages156-157 of the Lee 2nd addition.
Thanks guys.