Herzo Wrote:I should have noted that the effect of over gassing in my case was a failure to extract and tearing a segment of the rim from the cartridge. The bolt was moving before the case had time to relax.Understood. Yeah, my searching for action timing revealed a number of sources that explained that specific concern rather well, just without any timing/pressure curve/projectile displacement data.
I better understand how extended dwell times may impute similar issues, especially if I employ recipes that are at the edge of the pressure envelope for the given powder, projectile mass, etc. I am hoping that the buttoned 5R rifling profile may prove to be a bit more forgiving (lower friction, higher velocities, when contrasted with a 6-land cut-rifling profile). I am wondering if (molly) coated bullets would net any meaningful differences, should those sort of issues arise.
Also, the different powders seem to provide a myriad of potential tuning options, by being able to influence the pressure curve profile a bit. I found what I perceive as a good text on some propellant grain structure designs, and how deterrent coatings are used with various grain structure designs to tweak the burn/pressure profile.
This is definitely something that one can run down the rabbit hole with, quite deeply and quickly. It is stimulating from an intellectual/academic perspective.
As always, Thanks. Take care.
-MHz
si vis pacem para bellum