Thread: First time reloading: 7mm08

Originally Posted by Tankd

Velocity is not a measure of pressure , but it is an indication of pressure. More velocity requires more pressure. You can play around with different powders to get a bit more velocity for the same pressure, but this is largely small differences..all it tells you is how fast the projectile is going and yes chronographs Lie Yes, chronographs can be wrong but with at least 11 readings in the expected range I wouldn't be calling it wrong in this case without a very good reason . Pressure signs can show with both over and under loaded ammunition , which can be confusing as there are other things which can make you think there is to much pressure .
Your powder is on the fast side , for the projectile , and the projectile is on the heavy sidefor the calibre which isn't bad . But a rule to use is for any given calibre is that fast powder for light projectiles and slower for heavy . Most likely your load is not going as fast as the chronograph has told you and with no signs of pressure there were pressure signs at 39.5gr, and with magnum primers signs might not show up as well you are still safe at 42gr , reloading manuals are only a guide not an absolute because idiots love blaming someone else for their cockups .
Personally I would use the next slower powder , but your choice will still work , although at 42 you are at pretty much max for gain with out pressure problems , and I would do a pressure ladder test again to see if you are getting false velocity readings as I suspect.

With pressures possibly 30% above max, a lot of caution is good idea.