Bullet setback from shipping damage

[Dave Lively]

I went to the range last weekend with some 9mm ammo bought about 5 years ago. While l was loading a magazine I noticed one of the rounds looked more like a 380 than a 9mm. The box it was in looked a little damaged but not enough that I suspected a problem. The plastic carrier for the shells was noticeably bent but I have seen worse. I buy this by the case so I suspect UPS dropped it and the crushed round was on the corner of the case that caught most of the impact. I don't remember getting a badly crushed case but it was five years ago. I probably looked at the boxes and thought there would not be a problem.

The setback measured .105 inch. I have seen claims that .1 inch of setback in a 9mm or 40 can nearly double the pressure. That seems like a lot but I am glad I noticed.

Just a reminder to pay attention while shooting. Just because the previous 5000 rounds were fine doesn't mean the next one will be.

 

[ralph7]

A couple raps with an inertia bullet puller should fix it.

 

[Sevens]

A couple raps with an inertia bullet puller should fix it.

That’s a bad plan. It might make it look better and it might be okay in a single shot or a revolver, but in a semiautomatic that subjects each round to a violent feeding cycle, that round is just begging for a high pressure event.

Pull it down or throw it out.

 

[ralph7]

That’s a bad plan. It might make it look better and it might be okay in a single shot or a revolver, but in a semiautomatic that subjects each round to a violent feeding cycle, that round is just begging for a high pressure event.

Pull it down or throw it out.

I beg to differ, that's like saying using reloads in older used brass is dangerous for the same reason. If you are that worried about that then recrimp it.

 

[Dave Lively]

Pull it down or throw it out.

I am going to discard the ammo. I haven't touched my reloading equipment in years and its not worth dragging it out for this.

 

[Dave Lively]

I beg to differ, that's like saying using reloads in older used brass is dangerous for the same reason. If you are that worried about that then recrimp it.

I always resized the brass for semi-auto cartridges before reloading them. The tension from a tight fitting resized case seems like it would have a bigger impact on preventing setback than a taper crimp would. But as a recovering reloader I will defer to those of you that still do on all reloading issues.

 

[Sevens]

I think a deeper explanation is of value here.

9mm is a round that most handloaders do not actually “crimp” in to place. Yes, the bullet seat/“crimp” die will impart a taper crimp however a taper crimp isn’t meant to lock a bullet in place in the way we see it in a revolver cartridge with a roll crimp.

A properly applied taper crimp serves the purpose of un-doing the previous mouth flare. As the 9mm is designed to headspace on the case mouth, a roll crimp is neither typical nor expected and a normal handloader’s die set is only going to taper crimp. And a taper crimp isn’t going to “grip” the bullet. And if you aren’t sure this is the case, take your 9mm seating die and screw that down and try it… you will get the opposite of more grip on the bullet.

What’s required is for the case to be resized — that’s where we will get the grip that’s needed.

I’m not trying to win the thread here, but this is a 35,000 PSI Max cartridge and one of the smallest combustion spaces in nearly all of gundom.

You can accidentally push a .38 deeper and you’ll be safe. A .45 a little deeper is mostly harmless. But these are 15-17,000 psi rounds. With a 9mm (or a .40 S&W), you absolutely do not want that space reduced, and with the extremely energetic feed cycle of a modern semiauto, especially a compact or subcompact 9mm pistol, a loaded round with questionable bullet pull is a dangerous round and in a simple risk/reward equation, tapping this with a kinetic puller and then going to your favorite plate rack is a poor idea.

 

[30-30remchester]

I throw nothing away. If mine I would inertial pull the bullet. Seat it at correct depth, paint the case head red with a Sharpie and make it the first round fired.

 

[ReloadforFun]

Contact the manufacturer. It's likely they will work with you on it.

 

[Nevada Ed]

I throw nothing away. If mine I would inertial pull the bullet. Seat it at correct depth, paint the case head red with a Sharpie and make it the first round fired.

I would make it the "Last" round fired..........
just in case something went wrong.

Why take a chance on cutting your range time down with a problem on the 1st round?

However if that was mine, I would break it down since the seal and OAL was broken.
Save the bullet, case and primer, for later use.

If not pulling, just toss it, one round is cheap and will not cause any damage to the weapon.

 

[Krogen]

First round, last round; it really doesn't matter much. The issue is that the bullet seems to be loose in the case. Unless the bullet is pulled, the case resized and the bullet reseated the problem will persist. When the round fed from the magazine hits the feed ramp, the bullet can be set back causing high pressure. As noted above the 9mm is one of the more sensitive cartridges to this. It's high pressure to begin with and very little powder space. Bullet setback can be serious in a 9mm.

There's a lot of misinformation and misconceptions in this thread. Don't risk bullet setback in a pistol cartridge, particularly 9mm.

One can check for this by simply pushing the round against your bench. Really lean on the case head and see if the bullet goes in further. If it does, you don't have enough bullet tension to prevent setback.

 

[minconrevo]

If it is just ONE round then toss it. More the issue to me would be if the rest of the ammo of that lot has the potential to telescope back into the case upon feeding from the magazine.

My reloading dies (Dillon) significantly reduce the body body of the case, to the point that the base of the newly seated bullet is clearly visible. After I put a suitable, but not excessive, taper crimp on the reloads they are NOT going to telescope upon loading from a magazine.

In your case I'd suggest checking the rest of the box for push in potential.

 

[Paul in Nevada]

The shortened ones are not safe to fire.

If you pull the bullet back to the proper COL the rounds will function just the same as all the others. Nothing else has changed by pushing the bullets back. If the cases had poor tension in the first place, then all the rounds in that lot should be suspect. OP says he doesn't want to dig out his reloading supplies to correct them so he might as well just toss them.

 

[reddog81]

A properly applied taper crimp serves the purpose of un-doing the previous mouth flare. As the 9mm is designed to headspace on the case mouth, a roll crimp is neither typical nor expected and a normal handloader’s die set is only going to taper crimp. And a taper crimp isn’t going to “grip” the bullet. And if you aren’t sure this is the case, take your 9mm seating die and screw that down and try it… you will get the opposite of more grip on the bullet.

What’s required is for the case to be resized — that’s where we will get the grip that’s needed.

Yep, best case scenario you get lucky and somehow replicate the original neck tension that held the bullet in place. More likely then not anything you try and do will just reduce the neck tension and even if you get the right OAL, the bullet will setback when fed into the gun.

Good catch OP.

 

[Dave Lively]

If it is just ONE round then toss it. More the issue to me would be if the rest of the ammo of that lot has the potential to telescope back into the case upon feeding from the magazine.

If you look at the plastic carrier you can see it was bent in one corner. The short round was in that corner. Dropping a 1000 round case of ammo can generate a lot of force if it hits a corner. A 27 pound case of ammo falling 2 feet would generate 54 ft-lbs of energy.

This was probably shipping damage, not defective ammo. I am going to check the OAL of any rounds that are in the corners of boxes from that case that looked crushed or have bent carriers. But if the OAL is good I am not going to worry about shooting the rest of the ammo.

 

[ArchAngelCD]

Let me get this straight, we are talking about 1 round, right? Even if it's a handful of rounds, since you haven't used your reloading equipment in a long time just toss them like suggested above. There is no reason chancing a ka-boom for a few rounds, even at today's prices.

 

[Nevada Ed]

as a note,
most new ammo use new cases, that are "Tapered"
and some company's "Seal" their bullets and primers.

Even if not sealed, in a tapered case, if a ball 124 gr or heavier, with a taper crimp,
it would take a lot of pressure to set back a bullet to the OAL, of the pictured bullet.

I would guess a small amount of fast powder or a 115 gr bullet, might
be what was used in this loaded ammo.

My 9mm loads with a medium or slower powder, would never setback to that OAL, due to the amount of powder used.

I also agree with testing a few of the loads to see if the bullets have enough case tension, or if the box of ammo is of poor quality.

Thanks for the post.
It gives a few of us something to talk about in these times when we can't go out and be shooting.

Stay safe.