On a compressed load, how much is too compressed?

[deertaker]

I am working on a load for my 300 and called hogdon and hornaday they say that 81 grains is max and it is a compressed, but it really seems to be allot and the bullet really has to go in a long way, how do you know when it is too compressed?

 

[joe-nwt]

Sometimes with a heavily compressed load the case will bulge when you seat the bullet. Other times, with no crimp, the powder can push the bullet out after a while.

 

[Davidf]

Too compressed means the case bulges and the cartridge won't chamber well, or the bullet is noticably deformed during seating, or the COL grows after seating as thge bullet is pushed back out.