Kevin Stenberg
Well-Known Member
Thank you GENTLEMEN Kevin
One other thing to realize, aside from all the things that affect ignition pressure rise before the bullet moves, and while it moves the first 1/8", is how far down the barrel the pressure peak occurs. Some powders will peak before the bullet base is out of the case neck, while others will peak after the bullet has moved two or three inches down the barrel. Alloy, alloy temper, bullet shape, size, lube quality, jump, neck tension, crimp, all affect when and where that peak occurs, and how consistently in the same place is that peak.
The best way to approach this may be to pick ONE cartridge and bullet, and discuss all the things we can do to optimize the launch.
For both 30-30 and 308 with 180 gr cast in the 1900 fps range I use SR4759. Pity it's been discontinued
AgreedRX7 or IMR 4198.