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Discussion Starter · #1 ·
I have heard about repeated chambering and unchambering rounds causing bullet setback and increasing the risk of blowing up the chamber. Since I have a limited supply of cash to be consistently buying SD ammunition, I wanted to see how much of a problem it is. I took 10 rounds of 124 gr. +P and chambered each one in my G26 ten times. I measured the overall length of each one after each chambering and got some interesting results. Has anyone else done any home studies on bullet setback, if so, would you please comment on it. If this post is in the wrong forum, would the moderators please put it in the right place.

Thanks for all of the help.
 

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I tested my G37 when I got it, just like I do all new guns. I did not notice any setback at all in any of the 5 different loads I tested....
 

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Heh.

Looks like most of your ten bullets became longer after ten "re-chamberings" with only three remaining the same length. Based on your statistical population (n), it would appear that "bullet setback" is not an issue over ten such instances (at least in your gun) and that you've nothing to worry about.

I've never worried about it though because I shoot my loaded carry ammo at the range each trip and replace it with fresh stuff everytime. Ammo's cheap (even at today's prices); my safety and security ain't.

:)
 

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I have rechambered golden sabors several times and from time to time I measure them ,I have never had one set back on me......just sayyin:whistling:
 

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It happens and mostly on reloads. I had a 1911 kb and it is something to remember. All you have to do is just watch your ammo.. after my kb I checked my ammo and had a couple more set back. It isn't a big thing to just watch your ammo. It is easy to see.
 

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When I was carrying a G27, I chambered and rechambered a Win. Ranger T round about 7 times. There was noticeable setback.
 

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I prefer setback, makes more pressue buildup for deeper bullet penetration......







....this is of course a joke.
 

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Heh.

Looks like most of your ten bullets became longer after ten "re-chamberings" with only three remaining the same length. Based on your statistical population (n), it would appear that "bullet setback" is not an issue over ten such instances (at least in your gun) and that you've nothing to worry about.

I've never worried about it though because I shoot my loaded carry ammo at the range each trip and replace it with fresh stuff everytime. Ammo's cheap (even at today's prices); my safety and security ain't.

:)
I was thinking the same thing.

He either entered the results wrong on the grid, or else he had bullet set up, not bullet set back!:upeyes:

I mark a ring around the brass with a sharpie after ejecting the round. After 3 rings it's target ammo.
My Sig P232 mashed the hell out of hollow points with just one chambering.

****
 

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It happens and mostly on reloads. I had a 1911 kb and it is something to remember. All you have to do is just watch your ammo.. after my kb I checked my ammo and had a couple more set back. It isn't a big thing to just watch your ammo. It is easy to see.
Doesn't happen on my reloads, and it doesn't seem to happen on factory rounds.

If you are getting setback on your reloads, then it sounds like your bullet tension is too low. Maybe a tigher sizing die, a little more taper crimp, or a slightly larger projectile.

A fully fixable problem.
 

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We had an officer who unloads his Glock 22 every night, and he reloaded the same round each time. After about six months the bullet came out of the case just like it had been pulled with an inertia puller. The bullet stayed in the barrel and the powder spilled out when he unloaded it. He now rotates his bullets so he isn't chambering the same round each time. But he didn't have any set back.
 

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i checked mine a while back, a 23 w/165 gold dot. these have been rechambered many times and found no real set back issues. i used a caliper mic.
 

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Discussion Starter · #14 ·
I also interpreted the posted chart as showing either little or no set-back; inconsistent measuring; or the cartridge length actually getting longer (the opposite of set-back).

Yeah, I noticed how the measurements of some of the rounds ended up being longer than the originals after several chamberings. I have no explanation for these findings. I measured all of the cartridges at exactly the same spot every time. I guess the only explanation for it is inconsistent pressure on the calipers. (I had just bought them and the thumb wheel was a little stiff. Adding to this the fact that I don't do any reloading, so I'm not used to using calipers.
 

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i never thought of the bullet being pulled, but it makes sense. i will watch for that also.
 

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According to what I see, the same as most others....you might of found a new method to pull bullets.

This was done on a G26, 9mm....was that caliber/model identified as one of the problem models for bullet setback? Anyone else take a measurement of different models/calibers...I'll try to work one up for the G30sf..
 

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The same test has been done on military semi auto rifles and they had the same result. No setback but the bullets would get longer.

This is the kinetic hammer principle. The bullet gets slammed to a stop on chambering making the bullet slide forward each time.


I will try to find the article it may have been in handloader magazine.
 

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It happens and mostly on reloads. I had a 1911 kb and it is something to remember. All you have to do is just watch your ammo.. after my kb I checked my ammo and had a couple more set back. It isn't a big thing to just watch your ammo. It is easy to see.
GEE a KB on a 1911 and with out the required 100,000+ repeats and comments of how unsafe they must be, what do you know about that?
But on a more practical note, yes constantly rechambering the same round,in ANY semi auto can cause set back eventually, that little tid bit has been known for as long as semi Auto pistols have been in use. While I was still working,(as a cop) there were days I had to unload and lock up my hand gun ten or fifteen times a day, booking prisoners, going to court for testimony, ect. So my duty ammo got "recylced" several times in a month.
What I did was, drop the mag, and clear the chamber. Then place the pistol in a lock box. When I reclamed it a mag off my belt went in the pistol and the first round was cambered. The round that had been in the chamber went in my pocket and the light mag, was topped off from the box of spare ammo in my car then. When I got home any rounds in my pocket were stored, ( a dish on my dresser) till I went to my weekly range session where all my duty mags, 1 in the pistol 2 on my belt and 2 in my briefcase were emptied then reloaded with new ammo. I never used handloads in my Glocks, or as duty, or off duty SD ammo. Since my duty pistol was a G-21 I saved the brass to handload for a 1911. I have been retiered for elevin years now, I really feel for the young officers who work for depts that specify what ammo is allowed but only supply a duty load once a year or so. I realize that ammo is expensive but I always looked at it like car insurance, it is somthing you need and the better you have the better off you are.
 

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I unload and reload my G31 with Corbin .357 115jhp all the time and no setback (check new round in ammo box) But I am paranoid about my reloads if i unload and reload i check to make sure it didnt move the bullet before shoot them
 

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I did an experiment some time ago with 380 ammo in a Keltec. I was measuring the setback of the second bullet under the one that was loaded under recoil.

The setup of the gun seemed to cause some setback on the second bullet in the mag rather than the first. Of course a P3AT doesn't have the mass to absorb recoil effects like a Glock does.

Some rounds may be more apt to have setack than others. 40's seem like one.
 
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