10-26-2015, 11:55 PM
The Stoney Point/Hornady gauge will do this. I have done this with F-Class barrels. Set aside a projectile and keep this with the gauge (must be exactly the same projectile used over the barrels' lifetime). Don't put too much forward pressure on the soft copper bullet when taking readings to avoid deforming the bullet.
If you want a fixed jump-to-lands then you will be chasing the throat as it wears to the point your re-loads will no longer fit in the mag. All barrels wear at the throat where the pressure is concentrated. That said, 52' is correct, throat erosion may not affect accuracy given you can chase the lands for a period of time.
If you want a fixed jump-to-lands then you will be chasing the throat as it wears to the point your re-loads will no longer fit in the mag. All barrels wear at the throat where the pressure is concentrated. That said, 52' is correct, throat erosion may not affect accuracy given you can chase the lands for a period of time.