You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Bullet design
- Thread starter Hog head
- Start date
Not necessarily. The composition has to be similar. In another thread I just pointed to an experiment in the 70's by the NRA's Wm. C. Davis, Jr., who loaded ten different 150 grain flat base bullets over the same powder charge in a .30-06 and got pressures that ranged from 44,500 CUP to 51,900 CUP using the same case, powder charge and primer. Add in the switch to a boattail, and the swing will be even wider. Throw in a switch to a copper solid from cup and core, and it could be a lot wider.
However, if you use the same construction, as Davis did, Then the usual reduction of 10% in powder charge to get a starting load will reduce pressure about 20%-30% (depending on the powder) in most instances, so it's enough to get you outside the difference Davis had or that a boattail would make, so you can work up from there, watching for pressure signs.
However, if you use the same construction, as Davis did, Then the usual reduction of 10% in powder charge to get a starting load will reduce pressure about 20%-30% (depending on the powder) in most instances, so it's enough to get you outside the difference Davis had or that a boattail would make, so you can work up from there, watching for pressure signs.
Ok. That all makes sense. So now I'm out planning my experiments for the range and notice that to crimp into the cannelure the OAL will be 2.800. My closest data says OAL will be 2.735. Won't that .070 extra in the case be even more pressure or will the 10% powder decrease still be in the realm of safety. The bullets are bulk bagged no name and a magnet sticks to them. I'm assuming their military ball.
When I reload for my Garand using "pulls", I pick a similar size, shape, and weight bullet from my Hornady M1 Garand section and seat to the OAL listed there. I disregard the cannalure. I also have some HXP surplus that I can use for a "control" for duplicating military ball cartridge dimensions...