How Afraid of Bullet Setback Should I Be?

[RHFactor16]

I had a scary realization recently that I don't know anything about bullet setback, and I'm worried that I could be a prime candidate for a "kaboom." I don't reload (yet), and I'm pretty new to concealed carry so this issue is new to me. I carry with a round in the chamber, and I clean my carry guns at least once a month. Consequently, I'm loading and unloading my .380 Bodyguard using Federal Hydra-shoks and .40 Shield using Gold Dots several times between firings. I do rotate which rounds go in the magazine and which round goes in the chamber after each cleaning. From the limited research I've done, the .40 seems to be a problem child for bullet setback... how concerned should I be???

I'm thinking of investing in a digital caliber to measure any bullet movement in my personal defense rounds, but I would hope that the makers of these cartridges understand that the rounds are going to be subject to treatment that your typical target rounds aren't and would plan accordingly... but maybe I'm being naive and/or overly optimistic.

Does anyone else worry about bullet setback? Do anything to mitigate it? Can anyone wiser and more experienced please shed some light on this for me?

Thank you in advance!

 

[Hunter8282]

I read a tip somewhere to take a fine point sharpie and draw a circle around the bullet at the case. You can easily see this line. Use the same bullet to chamber and you can keep an eye on the line. If it were to disappear, I would not chamber that round anymore unless I was going to shoot it.

I have yet to have a line disappear, though I just started doing this...

 

[Ksimons]

http://smith-wessonforum.com/smith-...s/296922-setback-issue-please-educate-me.html

 

[D Rock]

I think it's something that you should watch from. It can be extreme or minor, but you should be especially careful if you rechamber a round often.

Here's a pic of a round of Hornady XTP on the left that I took out of a friends Glock 17 when I was going to put a different connector in for him. Fresh round on the right for comparison.

You can check side by side with a fresh round or you can get calipers if you like. I like the Lyman Case Gauge.
Lyman Max Cartridge Gage 9mm Luger

Dave

 

[shawn mccarver]

I had a scary realization recently that I don't know anything about bullet setback, and I'm worried that I could be a prime candidate for a "kaboom." I don't reload (yet), and I'm pretty new to concealed carry so this issue is new to me. I carry with a round in the chamber, and I clean my carry guns at least once a month. Consequently, I'm loading and unloading my .380 Bodyguard using Federal Hydra-shoks and .40 Shield using Gold Dots several times between firings. I do rotate which rounds go in the magazine and which round goes in the chamber after each cleaning. From the limited research I've done, the .40 seems to be a problem child for bullet setback... how concerned should I be???

I'm thinking of investing in a digital caliber to measure any bullet movement in my personal defense rounds, but I would hope that the makers of these cartridges understand that the rounds are going to be subject to treatment that your typical target rounds aren't and would plan accordingly... but maybe I'm being naive and/or overly optimistic.

Does anyone else worry about bullet setback? Do anything to mitigate it? Can anyone wiser and more experienced please shed some light on this for me?

Thank you in advance!

Bullet setback is a problem in any auto pistol cartridge, not just the .40 S&W cartridge.

You need not be afraid of it.

Either rotate the round being chambered, and it sounds like you do. Or, do not unload and reload so often. Store your gun in a vault when not being carried, and press check or view through the loaded chamber indicator hole to check condition.

You can check for the condition by standing the cartridges side by side on a flat surface and, using a straight edge on top of the bullets, check to see if any of the bullets is seated deeper than the others. Discard those that are seated too deep. Precise measuring is also good, but takes longer.

The makers do plan for a certain amount of "abuse" caused by chambering, but remember, too much crimp will also dramatically make pressures higher.

The answer is to quit chambering so much. On the other hand, that requires very safe storage when the weapon is not on your person, and some people just do not have that option. If you don't have that option, you should invest in a vault.

 

[gwpercle]

The permanant marker is cheaper and works for all ammo. Also the condition is very easy to see. Mostly happens when the same round is repeatedly reloaded in a semi-auto , setback occours after repeted hits on the feed ramp . And in hard recoiling , light weight revolvers. Just keep an eye on ammo in your gun.
gary

 

[RHFactor16]

Thank you

Thank you very much for the great ideas and information. Sorry for the repeat thread.

 

[Alnamvet68]

Since I only carry J frames concealed, they are, by necessity, loaded, and I have no fear of any setback.

When it comes to my semi's, I never chamber a round unless I plan on shooting the gun shortly thereafter. I also keep fresh ammo, or older ammo, in their original factory packaging...I really never could get why some folks just dump fresh factory, or BubbaHandLoaded ammo into a pail, milk can, garbage can, or a Dempsey Dumpster. I for one do not use reloads, don't trust them, and most certainly do not store ammo in receptacles that were never designed for safely storing ammo.

Lastly, I have a 2 year rule, and that simply menas any unfired ammo that has not been used in 2 years gets fired as soon as convenient, but not before a carefull inspection of the ammo.

 

[Turnedforgood]

Excuse me if I am ignorant here, but would this not be completely resolved if when you go to re-chamber your gun, instead of loading one from the magazine, load your first round directly into the barrel and then load the magazine?

 

[RHFactor16]

Magazine Load Only

I understand your reasoning, and that very well could work; however, my Bodyguard and Shield owner's manuals specifically say not to do that. I think it's b/c of damage that can occur to the extractor b/c it has to bend over the round instead of the round sliding up out of the magazine and into position. Maybe other guns with different components would allow for that? Anyone know?

 

[Vespers]

Excuse me if I am ignorant here, but would this not be completely resolved if when you go to re-chamber your gun, instead of loading one from the magazine, load your first round directly into the barrel and then load the magazine?

On some guns you damage the extractor. It can be done on some. The Beretta 92 comes to mind. I'm sure that there are others???

 

[PERAZZI]

1911's don't like doing that at all!! (Colt's anyway)...

 

[robkarrob]

I have a Ruger LC9 9mm, a Shield 40, and a Springfield XD45. I always carry with one in the chamber. I open the slide, drop the cartridge in, and let the slide slam closed. I then insert a full magazine. I never have a setback issue. I use the same cartridge over and over again, until I get to the range, when I use that cartridge for a practice shot. Since the cartridge was dropped into the chamber prior to the slide closing, there is nothing to cause pressure to drive the bullet deeper into the casing. That is why the ejectors have springs on them, so that they can move over the rim, and snap back into the extractor groove and lock under the rim. If your gun does not have a spring loaded extractor, then this would not work. I personally have not seen a modern pistol that doesn't have a spring loaded extractor. But then there are so many guns around that I have not seen. I can not see why the instruction manual would tell you to not load the chamber first, unless they think this might be so type of safe handling issue.

Bob

 

[RHFactor16]

Conclusion

Based on your insights and advice I ordered a digital caliper from Amazon which showed up yesterday, so I got out all my bullets and had a little science experiment. Here's how it broke down:

Bullets I tested:
.380 – HydraShoks that had all spent time in magazine and/or the chamber
.40 - Gold Dots that had all spent time in magazine and/or the gun, new Gold Dots, and new Blazer target ammo

Tests:
-Measured all bullets for Over All Length (OAL)
-Cycled and measured one round 0,1,2,3,5,10, and 15 times

Here's the results:
.380 -
-Mag 1 +1 Measurements: .944, .946, .942, .946, .939, .948, .940
-Mag 2 Measurements: .938, .941, .938, .938, .935, .936
-1 HydraShok Cycled Repeatedly (0,1,2,3,5,10,15 times): .940, .939, .939, .939, .939, .939, .941

.40 -
-Mags: 1.110, 1.113, 1.111, 1.110, 1.113, 1.112, 1.111, 1.112, 1.112, 1.112, 1.110, 1.110, 1.112, 1.112
-New: 1.111, 1.116
-New Blazers: 1.123, 1.121, 1.121, 1.123, 1.118, 1.120, 1.120
-1 Gold Dot Cycled Repeatedly (0,1,2,3,5,10,15 times): 1.110, 1.110, 1.111, 1.110, 1.110, 1.113, 1.110

Conclusion... Doesn't seem like much to worry about here. The digital caliper was only 15 bucks so there's a chance for some slightly off measurements, plus the mouth of hollow points aren't always nice and smooth and uniform so I'm not worried about a couple of thousands of an inch.

I know that bullet setback is a real thing; however, it doesn't appear to be happening in my guns. Maybe 20-30-100 cycles would be a different story, but I plan on replacing my carry rounds about every 2 years. I also went ahead and drew a line on each bullet so I can visually track any movement going forward.

Thank you all for your input and advice, I feel much better about my guns and carrying them for self-defense.

 

[Rastoff]

RHFactor16,
I've been a Metrologist for 29 years now and it does my heart good to see someone actually take the time to do some measuring like you did. Good for you!

Now that you've done some measurements, don't become complacent. Even though your measurements showed that the bullet wasn't set back significantly over 15 cycles, that doesn't mean the next bullet won't do it. Minor set back of a few thousandths is not an issue, but set back like D Rock showed is significant. That can cause serious pressure increases in the chamber and could damage the gun and maybe the shooter.

 

[Rastoff]

I wanted to address this issue separately:

Excuse me if I am ignorant here, but would this not be completely resolved if when you go to re-chamber your gun, instead of loading one from the magazine, load your first round directly into the barrel and then load the magazine?

Dropping a round in the chamber and then closing the slide is not the recommended method.

All of the M&P pistols(not revolvers) have an external extractor. The benefit of this is that it is an articulated extractor. This means that the extractor has a pivot point and is designed to move enough to clear the rim of a cartridge that is already in the chamber.

1911 style guns have a fixed extractor. While it will bend around a case rim, it runs a much higher risk of breaking. For this reason, a 1911 should never have the slide dropped with a round in the chamber.