On occasion, I will be at the range and for whatever reason I will drop the mag, clear the gun, (happens a lot in competition) and rack out a live round making the gun safe. Well I never really thought about that round that’s been chambered as I usually just put it back in a mag and then shoot it some time either that day or another. Question is I know rechambering the same round over and over is not a great idea as it can cause setback though does anyone ever experience this from just a couple chamberings of the same round?

I don’t ever see it with Speer or Hornady pistol ammo. It takes a LOT of cycling to see set back on quality ammo.

^^^^^ Makes sense as I feel it shouldn’t happen with quality ammo even after a few times. I try and always shoot quality factory stuff. Usually shooting 9mm probably 90% of time vs other calibers and mostly use S and B, Blazer Brass, Am Eagle, Winchester (usually the NATO though never an issue even with 115gr. WWB), Fiocchi, etc. and never encountered any setback that was obvious anyway. Haven’t checked unless I would chamber a JHP round in a carry gun a few times, even then never an issue.

Just got to thinking today after being at the range and racking one out only to put it right back in the mag a short while later, rack it back in the chamber and shoot it. Didn’t really think if I should have checked it as it was only twice being chambered, but wondered if anyone else has seen any issues after just a couple times, because if so I’ll start paying more attention.

More than a couple of chamberings, but I've saw it happen to some jhp 357sig ammo.
And yes, you could tell simply by looking at it.

quote:

Originally posted by jljones:
I don’t ever see it with Speer or Hornady pistol ammo. It takes a LOT of cycling to see set back on quality ammo.

+1. Unless you are repeatedly ejecting and rechambering the same round, I wouldn't give it a second thought. Even then, I'd be more concerned about the condition of the case rim rather than bullet set-back.

quote:

Originally posted by Excam_Man:
More than a couple of chamberings, but I've saw it happen to some jhp 357sig ammo.
And yes, you could tell simply by looking at it.

JHP 357Sig is the only time I've seen it as well.

Sig V-Crown IIRC.

I use the same carry ammo for a year, then shoot it up.

I shoot this gun once a week minimum, every week for that year and during that time, I put the live round back in. What actually happens is the top 2 take turns being rechambered due to the nature of the way it happens.

I've done this for well over 25 years and have had no problems whatsoever, mostly because setback will increase pressures, but not significantly. I've posted a graph of it that Speer/CCI did on this board at least once that shows it's still safe. Pressure never even gets near proof round pressures.

Lucky Gunner also did a non scientific test of this years ago and came to the same conclusions.

I've never experienced setback from rechambering the same round, and really can't visualize a scenario in which I'd be rechambering the same round over and over. Nonetheless, I tend to remove a couple rounds from the magazine and refill it so a "fresh" round goes into the chamber. It's probably pointless, but a habit I accrued over the years.

quote:

Originally posted by P250UA5:

quote:

Originally posted by Excam_Man:
More than a couple of chamberings, but I've saw it happen to some jhp 357sig ammo.
And yes, you could tell simply by looking at it.

JHP 357Sig is the only time I've seen it as well.

Sig V-Crown IIRC.

Not surprising given the design of the case and its short neck.

I have also seen people talk about it with .40, but I don't know why a .40 would be more prone to it than say a 9 or .45, though maybe it gets talked about more because .40 pressures will shoot up faster with bullet setback than a 9 or .45.

I unload and unchamber my 9mm Khar CM9 carry gun each time I'm done with it and lock it up as I have 3 little children in the house and I've gotten in the habit of changing out that first round after a while as it does get bullet setback. I count it as the cost of safety.

The manual of arms for the Kahr requires you to press the slide release to charge a round rather than slingshot and I think this contributes to that setback as it's quite a strong spring and it chambers quite firmly.

quote:

Originally posted by Flash-LB:
I use the same carry ammo for a year, then shoot it up.

I shoot this gun once a week minimum, every week for that year and during that time, I put the live round back in. What actually happens is the top 2 take turns being rechambered due to the nature of the way it happens.

I've done this for well over 25 years and have had no problems whatsoever, mostly because setback will increase pressures, but not significantly. I've posted a graph of it that Speer/CCI did on this board at least once that shows it's still safe. Pressure never even gets near proof round pressures.

Lucky Gunner also did a non scientific test of this years ago and came to the same conclusions.

Same here. Normally, it's only the top few rounds that undergo any re-chambering anyway. Not an issue.

Talk about setback. Had a student in one of our NRA courses shooting Rem-UMC 9mm 115gr ball. Instructor noticed something odd and called me over. Were three rounds in the box sitting lower than the others. Inspected them and took them home before contacting Remington. The setback was ONE-TENTH of an inch (measured). Can't just assume that even factory new un-chambered is necessarily good-to-go. Inspect first.

Something I forgot to add was that bullet setback is a non-issue for me. However, I do replace rounds on occasion when I notice burrs that start to develop on the rim where the extractor grabs it. Happens occasionally and I just wind up throwing it in a box of loose rounds to shoot at the range.

Just remembered something that used to happen years ago.

I shot at a different range than I do now. Once a year or so, a local Sheriff department deputy would come in to shoot and turn some ammo he had with setback into the range for disposal. We met, he noticed I was picking up my brass and asked if I'd like to have his setback ammo to take apart and reload. I said sure.

After he left, I emptied them downrange and then reloaded them when I got home.

Did that with him for a few years, then I changed ranges and haven't seen him since.

It shouldn't cause setback unless you are jamming it hard into the lands. I suppose, in a semi, the feed ramp could push on the bullet a little, but factory ammo should be crimped enough that several re-chamberings shouldn't cause any meaningful problem.

I think this is more a theoretical problem than an actual one. Maybe the shorter neck of .357 Sig could grip the bullet less, but . . .

Some years ago, I did notice some set back when using the old W-W Silvertip load in 45 ACP. Nothing since.

They talk about this issue on Brownells


Smyth Busters: Will Excess Bullet Setback Blow Up Your Gun?

https://www.youtube.com/watch?v=8KzbA4cS5yg

I don't always rechamber the same round, but when I do, I check it for bullet pushback or dings/nicks in the rim/extractor groove and discard it if anything looks wrong. Just a couple of times is unlikely to cause either issue.

Is it a thing? Sure. Is it a thing I worry about? No.

We used to see it on occasion with the Golden Sabers we used for duty ammo early in my career, but I don't recall seeing it in a decade or more with Gold Dots or HST.

Cheap practice ammo is likely more prone to it, but you probably won't be repeatedly rechambering FMJ ammo anyway.

If you're concerned about potential bullet setback, it only takes a second to stand the round in question next to a known good round and give it an eyeball.

You don't necessarily have to rechamber the very same round. Your magazine is out of the gun but still filled, I assume. Insert the mag, chamber the top round, remove the mag, load your loose round into the mag, and insert the now fully-loaded magazine. That reduces the wear and tear on any one cartridge.