setback never knew about it

[tango3065]

I use 180gr in my new 40cal CZ and I have chambered and hand cycled a couple full mags 3 or 4 times, you think these rounds are ok?


Can I just sit them up on a flat surface and compare them to check for setback?


Also the rounds are WWB JHP and each one shows the little crimp notches on the actual bullet just before the end of the casing, so couldn't I just look to make sure all the crimp notches are still showing and they haven't been pushed into the casing?



BTW this is a problem I have never heard of and I am glad I read a post that mentioned it and done more research on setback so now I know that if I chamber a round I leave it in there or shoot it, especially on a 40 cal from what I read.

 

[Handgun Midas]

This is the first I've heard of the term "setback," but I had some JHPs that were being loaded, cycled, and unloaded in my carry piece for over two months before I took it to the range to shoot that old ammo up.

I was pretty certain that all the wear'n'tear over all the cases and bullets would cause malfunctions, but the pistol ate them all just fine.

 

[shotgunkevin]

Setback is very dangerous. The less space the gunpowder has in the case, the higher the pressure will be. Most cartridges intended for autos already run near maximum pressure as it is. Firing rounds with set back bullets will accelerate wear on your pistol, and could very well lead to injury to the shooter.

Can I just sit them up on a flat surface and compare them to check for setback?

That's basically all I do. I compare suspect rounds against a new cartridge from the same box. My XD sets back bullets pretty badly, and I don't trust an individual round that's been chambered more than 3 times. The short ones get tossed out. All my gloves have 5 fingers on each hand, and I don't want to buy new gloves!

 

[Reyn]

Never had it happen with a .40 but ive had it with a .357sig. It was my duty gun and i never knew it until one night at beginning of shift i unloaded to expect my gun. We have had several instances with other officers also. Not a whole lot but 3 deputies. This is over 2yrs in a 50man dept. I just dont load it and ease the slide down when loading.

 

[Ritchie]

I keep 7 in the mag and one in the chamber, when the piece is cleared the
2 rounds swap places. After this happens a few times both get rotated
to the bottom of the mag. After this happens a few times they all get
rotated to the range supply. Never seen a round with setback, these
are all factory HPs.

 

[bakert]

Anyone that uses auto loading pistols should be aware or find out about bullet set back. It can lead to a very dangerous situation especialy in fairly high pressure rds like the .40 S&W and 9MM. Instead of eyeballing the rounds I would check any suspect rds with calipers against maybe a half dozen of the other rounds in the box.. Although there may be small variations even with factory rds because most bullets will vary a bit anything that seems excessive should be not be shot. Some ammo can set back after being cycled from the mag only a few times.