There is some tolerance between the minimum OAL and max OAL. If you have a micrometer you can measure. One source from a reloading forum said:austinrealtor wrote:This is one of the issues I knew very little about until reading it about it online. I have searched the forum and read some other threads. Still not totally sure I understand it, so posting this photo and some questions regarding bullet setback.
These (photo below) are .40 S&W Federal HydraShocks from one of my Glock 23 mags. I have three mags full of these, but some are older than others. I'm honestly not sure how old this batch of ammo is, (yeah, yeah, I know - need to replace once a year). I bought a new box within the last year, but think these may be some holdovers I've had for a few years. The round on the left in photo caused me concern. The cartridge on the right appears to be from the same "batch" of ammo and is closer to what these rounds should look like.
Anyway, this seems to obviously be an example of setback. So my question is .... what do I do with this round? If I shoot it am I guaranteed a catastrophe? If I don't shoot it how/where do I properly/legally dispose of it?
"The SAAMI minimum/maximum cartridge OAL for 40 S&W is 1.085"/1.135". Thus if you start too close to the min OAL, you can seat below min during firing/feed and have a potential overpressure problem. Factory rds measured are generally in the area of 1.125" OAL "
Dont shoot it, if you dont know the OAL. Most ranges should take it off your hands.
I agree with the others about NOT manually chambering the round.