How much bullet setback is dangerous?

[Agustav]

The real problem here is not how much COL changed is acceptable (preferably none), but why did it change? Cycling a round one or twice shouldn't change your COL if the loaded round have proper neck tension or crimp.

If the COL is change during cycling by hand, the COL will change much more under recoil and subsequent chambering.

[toddh]

I reload, and pretty much stay within the dimensions of SAAMI.
It allows a bit of variance for different powders, bullet lengths, etc.
It isn't gospel...but it's a great way to verify dimensions when something doesn't look right.

And to test your crimp....take a round and press it against something solid by hand....the bullet shouldn't budge.



SAAMI specs for .40 S&W......