John Boy
03-15-2007, 01:33 AM
The Lee 459-500-3R is supposed to have a nominal diameter of 459. But using a 1:20 alloy, the bullets cast at:
Driving band - 464
1st GG Band - 464
2nd GG Band - 464
Base - 460
OK, but the normal groove dimension for a Pedersoli 45-70 barrel is 458 and rule of thumb is that the bullet should be 0.002 over groove for it to obdurate properly. These suckers will be 0.006 over groove at the bands using BP for the powder
I've shot them before out to 300yds (good groups) and was wanting to work up a 600yd load at the local range and then this Summer, shoot them out to 1000yds at Ridgeway in PA.
With the bullet being 'excessively' over groove diameter ... any thoughts about obduration impact?
Driving band - 464
1st GG Band - 464
2nd GG Band - 464
Base - 460
OK, but the normal groove dimension for a Pedersoli 45-70 barrel is 458 and rule of thumb is that the bullet should be 0.002 over groove for it to obdurate properly. These suckers will be 0.006 over groove at the bands using BP for the powder
I've shot them before out to 300yds (good groups) and was wanting to work up a 600yd load at the local range and then this Summer, shoot them out to 1000yds at Ridgeway in PA.
With the bullet being 'excessively' over groove diameter ... any thoughts about obduration impact?