I have got a quantity of PMP brass for my .223. have read that these have thicker walls making them heavier, which on the scales there about 10 grains heavier.
I have also read that you have to use lower charge in them due to being thicker brass....really and why??
I'm still green to all this, could some one enlighten me please.
Without curiosity, evolution would have been greatly flawed.....
email...... stephenbarrow@ntlworld.com
When the cartridge first fires the powder burns in a space made up of the chamber volume plus the space behind the bullet as it goes down the barrel minus the volume of the brass. More brass means less volume for the powder to burn in and higher pressures. So you have to drop the charge to get the same pressure.