I have done that with. The bullets just can't take the repeated trips while hitting the feed ramp. He might consider a bolt down, fast access handgun safe as a superior alternative to unloading and reloading his duty gun.

--
Of the Troops & For the Troops

If he does this every day then he needs to be aware of it and not keep doing it with the same cartridge. The photo shows a pretty extreme case. With the bullet seated that much deeper the pressures will be higher when the cartridge fires. Whether it matters or not would be difficult to answer but just a little change in case volume can make a big difference in pressure.

The best thing to do if he has to unload/reload every day is to watch the cartridge on top and when he starts to detect it getting shorter, put that cartridge aside for practice and put a new one on top. A single cartridge can tolerate a few hits on the feed ramp but doing it every day will eventually lead to a problem. Spread the hits around to more than one cartridge and he won't have to throw away any ammo.

I'd tell him to go to the range and run a box of ammo through it once a week. That'll keep him and the ammo both fresh.

-AaronB

It happened routinely for years with my .45acp stuff, especially with taper crimped handloads with jacketed bullets. I relegated the round to the plinking ammo pile, and shot it up with the rest. No pressure problems with non-+P level handloads in this caliber. I can't speak for hot rods like the .357 sig.

JLF

way back in the last century (!) when i was a butter bar, had a chance to go to an armorers school, old gent who ran it had a movie, it showed cartridges cycleing thru automatic weapons. some of those guns actually bent the round as it chambered! not too suprising then that a bullet gets shoved back; have had this happen with some non-auto rifles, such as my old M25 Remington when the bullets nose hung up on the breech.

But I can learn from my mistakes. When loading for high-pressure autopistol rounds like 9mm and .38 Super, I now back off the expander plug so that the first step will only enter the case mouth as deeply as the bullet base will seat, and the belling step does not even touch. Then I use a Lee universal belling die to flare the case in a separate step. After loading, the round gets run into a Lee factory crimp die to remove the case flare and give it a good taper crimp. This gives each loaded round a distinct "wasp waist" appearance and insures that it takes LOTS of pressure to push a bullet back in the case during the feed cycle.

OK, I'm paranoid about bullet setback, but after almost blowing a 9mm case in my treasured LW Commander years ago due to setback, I'm convinced that being anal about it is the way to go.

From Charles' photo, it looks like the bottleneck .357 Sig case has nothing except neck friction to keep the bullet from setting back, and there's not a whole lot of neck there....

I've seen this mentioned frequently among .357 Sig shooters on a number of forums. All auto cartridges will set back, if cycled into the feed ramp enough times, but I suspect there are several factors that make the Sig more susceptible to it. Extra-healthy recoil springs are one and I think the other is that the .40 size case head is simply better supported by the breech-face, and requires more force to tip the cartridge up into the chamber.

Regardless of the caliber, it's a good idea to discard any round that has become visibly shortened. Beyond any potential pressure issues, you know the crimp is failing, Chuck it in the pond and eliminate the problem before it gets worse.