This guy chambered the same 9mm round 100 times...

[Fordtough25]

I just rotate my carry ammo often and I don't worry about it much. I do look at the first round in the mag as I insert it into my EDC.

 

[rvb]

Consider this. You just loaded up a mag and chambered a round into your EDC. You then holstered your pistol, ready to face the day.

How do you know that this round was not pushed back into the case?

Nobody worries about it unless they have lots of spare time while sitting in front of the computer.

When I'm developing a load or testing a round for carry, I test for it... I'll chamber the same round numerous times looking for setback. For my reloads I want to make sure the bullet I'm using and my sizing/crimp setup is correct and for factory defensive ammo I want some confidence I can un-load/load the round a couple times before I have to be worried (seldom an issue as I seldom unload my carry gun.... from the holster to the quick-access safe it can stay loaded). That's how I "know" it's not pushed back (yea, " " around "know") enough to worry about.

You mis-understand but it is more likely that I am not clear. The bullet should never be slammed into the feed ramp. You can feel that. It does not feel good. I have had 1911's that did that. I fixed them.

The side of the bullet can certainly slide up the feed ramp. This feels good. This cannot push the bullet into the case.

whew, I'm glad you clarified that. I thought "Oh No! For the first time I'll have to disagree w/ sloughfoot!!!!"
I think it can still set the bullet back (because I've seen it & measured it), but it should take several times for it to be significant enough to cause concern.

-rvb

 

[Exodus]

Like in the other post rvb linked. Critical defense in my M&P 9 I get setback pretty quickly. Enough that I pull the rounds from carry status. When the cannelure is no longer visible I stop carrying it.

 

[nucular]

Ok guys here are my results from my sig. I am about to do the same with a glock 23.

Its up to you to decide whether the loss in height is from the hollow part of the round collapsing or the bullet getting pushed back into the case.

If you could place a mark about halfway up the bullet, you could measure from the rim to the mark each time. Then you could determine both setback and deformation.

 

[rvb]

If you could place a mark about halfway up the bullet, you could measure from the rim to the mark each time. Then you could determine both setback and deformation.

Or simply measure oal then pull the bullet and measure the length of the bullet.

-rvb

 

[nucular]

Or simply measure oal then pull the bullet and measure the length of the bullet.

-rvb

True but then you couldn't measure both setback and deformation over time. You would only know the end result.

 

[Leo]

Personal habits may affect this issue. For 40 years I never even gave it any thought until I started reading posts on INGO. Now that I have thought about the subject and paid attention to my actions, I understand why I never had an issue. #1, I carry a revolver about 1/2 the time, no problem. #2 when I load the semi autos, I drop one round into the empty chamber, and then "controlled drop" the slide to full battery. I then either set the safety or work the decocker before inserting a full (is there any other kind?) magazine.

The ammo stays that way until I shoot it or I may unload it to shoot target ammo or maybe to clean and dry the firearm if it has gotten wet. Either way, I do not rechamber a cartridge by strippling it off the magazine over and over. At any given time, probably 1/2 of everything I own is loaded to the top and ready to go. I have yet to have a "set back" bullet. Add to this I never crimp rifle ammo, even for semi autos like an AR. I fill a properly sized case will powder, and push a bullet in. What ever tension is on the neck, is all it gets. 10's of thousands of rifle rounds later, still no problem. For pistols I properly size the case, add powder and bullet and then I use just enough of the crimp die to close the case mouth to maybe .001" tighter than max SAAMI Spec. No real attempt at "crimping".

When I worked at the range, I would see dozens of loaded rounds tossed in the trash that were set back. I disassembled them for safe disposal. A lot of AR ammo reloads that were showing enough crimp to deform the bullet but still were set back so much the bullet was loose inside the case and powder was flowing out. I am sure some were from defects in firearms, but I wonder if a lot of the problem is from rough handling the arms and ammo like some overly dramatic gun handling movements you see on rambo movies.

 

[rvb]

For pistols I properly size the case, add powder and bullet and then I use just enough of the crimp die to close the case mouth to maybe .001" tighter than max SAAMI Spec. No real attempt at "crimping".

That's right, all you need to do is remove any bell. You don't even have to go under spec. I set my crimp so I can set a straight edge along the side of the case and not see any angling in or out at the case mouth. I shouldnt see any ring on the bullet if I pull one.

A lot of AR ammo reloads that were showing enough crimp to deform the bullet but still were set back so much the bullet was loose inside the case and powder was flowing out. I am sure some were from defects in firearms, but I wonder if a lot of the problem is from rough handling the arms and ammo like some overly dramatic gun handling movements you see on rambo movies.

Too much crimp can weaken case neck tension, and actually reduce the case's hold on the bullet. Also, on an AR, if a crappy mag looses control of the bullet, and the bolt smashes the round into the back of the receiver or barrel extension, then no amount of neck tension/crimp will keep the bullet from going way back into the case. I'd bet that's most of the y set back .223/5.56 you saw...

-rvb

 

[USMC-Johnson]

Now this one is a bit frightening. check out the change. i only made it to 75 before it stopped moving. I also believe its important to mention the round fed flawlessly the entire time and never got hung up or failed to feed.

 

[Lebowski]

Now this one is a bit frightening. check out the change. i only made it to 75 before it stopped moving. I also believe its important to mention the round fed flawlessly the entire time and never got hung up or failed to feed.

Oh wow! Big difference there.

 

[jtwilson3]

The reason you don't want to do it is the stresses this places on your extractor.

It depends on a few things of course. Almost every handgun I know of is pretty much controlled feed, meaning the round's rim goes under the extractor as it's leaving the magazine.

The extractor is not designed to snap over the rim of a casing. This will absolutely screw up a 1911's extractor tension and result in malfunctions, or a broken extractor.
For most other firearms, it creates stress at a few points on the extractor that were not designed to experience those stresses. This will eventually result in breaking or chipping your extractor.

It's important that you never do this again. If you've been doing it every day for years, you should consider replacing your extractor now, before it fails on you when you need it.

-------

As for bullet set back from chambering rounds... You should try a 1911 with a 24 pound spring and a tight chamber. (Clark 460 rowland kit build)
When I first started reloading 460 rowland for it, I didn't realize it'd require such a ridiculous crimp to keep the round from having massive setback even after chambering once. That said, it never blew up on me and I'm sure some of those rounds had to be set back far enough to compress the charge after chambering.
I don't think it's as dangerous as it's made out to be. I would never trust a questionable firearm to handle such a thing though, nor would I trust a firearm without good chamber support.

I've rechambered the same round of federal HST 147gr 9mm in my USP countless times now, and there's still no setback at all according to the calipers. Some guns are very gentle on ammunition, that USP doesn't even seem to leave a mark on the bullet.

Nope have done it a total of about 10 times in my life. I have only owned the gun for a few months. But every week or two I take out the main round and switch it with another in my magazine just to keep them rotated. That makes sense though. I will stop doing it though. At least somebody explained it to me calmly. Thank you. It's amazing how easily I and others are willing to listen when someone makes a reasonable and calm argument...

 

[scottka]

I used to be a big believer in avoiding bullet setback, but I've seen a lot of evidence that it isn't really as big of a deal as it is made out to be. Here is an article that I just found with a quick search, Battered Bullets: Does bullet setback matter? | The Daily Caller but I know there is a video out there somewhere that I can't find right now of a guy doing the same thing with, I think, a 9mm. Basically he ends up beating the crap out of the round with a hammer and then firing it, and it doesn't damage anything. I'm NOT saying that anyone should do that, but I am saying that I don't think the comparatively small amount of setback from chambering is anything to be overly concerned about. Under any kind of normal circumstances, I don't foresee it destroying even a semi-quality gun. I'll try to find the video as well.

 

[scottka]

FWIW, having said all of that, I still tend to cycle my rounds in my magazine instead of rechambering the same round over and over. I just don't think setback is as dangerous as it is made out to be. Then again, I'm basing most of this on others' research, not my own.

 

[in625shooter]

FWIW, having said all of that, I still tend to cycle my rounds in my magazine instead of rechambering the same round over and over. I just don't think setback is as dangerous as it is made out to be. Then again, I'm basing most of this on others' research, not my own.

All guns are made to exceed SAAMI standards within reason to a point however there is a breaking point after so many times exceeding it. 2 reasons where setback is dangerous more than one might think. 1. It will increase pressure. Sure you "might" be safe firing for a few times. If you use +P or +P+ rounds it will go into the unsafe category, and the more you decide to fire rounds the quicker your on borrowed time. 2. Reliability in the firearm cycling properly can be very adversely effected. Not a big deal on the range but practice ammo is only chambered once.

I advise once you notice it that is the time to discard it from being chambered anymore.

 

[USMC-Johnson]

Also if it is severely set back like with the last test i showed. whats to say that bullet doesnt get lodged in the chamber. then you have a seriously unsafe condition.

 

[Tombs]

Also if it is severely set back like with the last test i showed. whats to say that bullet doesnt get lodged in the chamber. then you have a seriously unsafe condition.

I don't think I understand you correctly. Lodging a bullet in the chamber because of setback? Do you mean the bullet being set back so far it's swelling the brass closer to the web and possibly lodging the case in the chamber?

I don't think that condition would be any more dangerous than the conditions created when a round is being fired.

I'd like to see some pressure testing done with bullet setback. I'm fairly confident it depends entirely on the burn rate of a specific powder. I do know if you get excessively compressed charges you can end up with squibs with some powders.

 

[USMC-Johnson]

I more meant if you have a short bullet and now its set back to far from the rifling and somehow it got somewhat hit so its somewhat sideways in the case now it gets caught on the lip between the rifling and chamber.

 

[88E30M50]

You mis-understand but it is more likely that I am not clear. The bullet should never be slammed into the feed ramp. You can feel that. It does not feel good. I have had 1911's that did that. I fixed them.

The side of the bullet can certainly slide up the feed ramp. This feels good. This cannot push the bullet into the case.

Edit to add: none of us can see what actually happens in the feeding process. But we can feel it. It should feel smooth no matter what is coming into contact with the feed ramp.

Ok, that makes sense to me now. I had taken your earlier statement literally.

 

[fw501]

Officer Safety: Ammunition cycling and failure to fire | The Bolo Report

 

[Tanfodude]

Anyone fired those set back rounds yet?