Squib waiting to happen?

[piefairy]

My understanding is that most pistol rounds are not full of powder. I know the ones I load aren’t, and in my particular .38 and .45 loads my powder load actually takes up less than half the case volume (and this is why when handloading for pistols one has to be very careful to avoid double charges - there’s enough, and often more than enough, room in the case for two drops of the intended powder charge). Also, bullets should really never be resting on powder, but seated to a proper depth and then held in place by sufficient crimp.

Rounds with that much setback put the otherwise safe powder load under more pressure by giving it less room to expand. If you ever get into handloading, this is why bullet/cartridge combinations have recommended overall length measurements.

This is also why self defense and duty ammo rounds need to be regularly taken out of use and replaced. After enough trips in and out of the chamber when you unload and load the gun, the bullet will start to set back.

Good info. I did not know this. I've thought about handloading, but it seemed like an easy way to screw up and a lot to take in at once, so I never got started after some basic research. I will have to cycle my self defense rounds on occasion then too. Another excuse to go to the range

[Noah]

I was assuming it was seated deep because of a lack of powder. So you think the charge is normal just compressed down? What would occur in that case? Damage to the gun?

With smokeless powder, bullet seating has nothing to do with powder charge- there will be a lot of extra room. Like others said, this will cause significant increased pressure due to a smaller space than normal for the explosion to take place.

Now, if we were talking black powder back in the day in the 1870s-1900, then yes, the case was the size it is in order to be packed full with the proper powder charge.

[JohnO]

Internal Ballistics is a science itself. What happens from the moment of ignition of the primer to when the bullet leaves the barrel falls under Internal Ballistics.

There are many factors that come into play and case volume is certainly an important factor.

Depending on the cartridge and the powder, small reductions in case volume can cause huge increases in pressure.

[RJ]

Ja setback is a thing.

I was testing feedway issues with hollow point ammo in my Garrison, using the same round over and over. After 15 reps, I took it out. It looked a bit, ah, short, compared to a fresh round out of the box, shown at left:

[piefairy]

Ja setback is a thing.

I was testing feedway issues with hollow point ammo in my Garrison, using the same round over and over. After 15 reps, I took it out. It looked a bit, ah, short, compared to a fresh round out of the box, shown at left:

I may just leave the last HP round in the gun when I go to the range and send it rather than throwing it back in the mag. What are the tolerances? Is the bit in RJ's photo enough to cause major issues or would that be acceptable? Its kinda scary to hear that even a big name like Lawman is having similar issues. I'll have to keep my eye on the ammo. I was buying name brand, well at least names I knew, thinking to avoid things like this. If they weren't so close in price, I might go back to shooting no-names or some reloads. But its averaging less than $25 a case difference so not really worth it.

[mmc45414]

OK, Big Disclaimer: I am not going to tell anybody to do anything or recommend anything, but...

The worry is a potential squib, if there is no powder, but with just 115gn practice ammo it would most likely just shoot normally, 9mm has a really thick case web and there is probably some airspace behind the bullet. With 147gn maybe not so much airspace, but then it probably wouldn't have setback so significantly.
Have shot may 45ACP reloads that were setback, NBD (low pressure cartridge).
The only one I would be afraid to shoot would be a 40S&W cartridge, the case web thickness is significantly thinner and the pressures are just as high.