Rechambering a round

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So I was visiting family and a cousin of mine who is a deputy warned me not to rechamber the same round "too many times", but he didn't really say what that was. I wanted to see if there was any consensus on how many times is too many. I dry fire my gun 3-4 times per week so I am clearing and reloading my gun frequently. How big of a deal is this, and what techniques do you use any special techniques with your ammo, like a rotation or something? I never really thought about it and have probably chambered every defense round I have (only got a box of 20) at least twice. Should I shoot it off at the range and replace it ASAP?

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I don't bother, but i've been known to throw the calipers on a round that saw alot of action just to ensure it didn't have the bullet seated deeper than it's twins.

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I've rechambered rounds that had FTF before, with gouges on teh brass along both sides. no issues with them.

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asforme wrote:

So I was visiting family and a cousin of mine who is a deputy warned me not to rechamber the same round "too many times", but he didn't really say what that was. I wanted to see if there was any consensus on how many times is too many. I dry fire my gun 3-4 times per week so I am clearing and reloading my gun frequently. How big of a deal is this, and what techniques do you use any special techniques with your ammo, like a rotation or something? I never really thought about it and have probably chambered every defense round I have (only got a box of 20) at least twice. Should I shoot it off at the range and replace it ASAP?

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Having a 1911, I just put it in the chamber and let the slide down slowly til it locks and then put themag in.

TJ

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I know exactly where this is coming from. Its a big deal in the military in Iraq to constantly "rotate your rounds". When a round is in the chamber in your M4, the firing pin puts an ever so slight pressure on the primer on your round. After a few times, you can see the mark on the primer. After the firing pin keeps hitting the same spot ever so slightly, it eventually goes off upon loading. This would be very rare in pistols. Regardless, just look at the round before reloading. If you can see the firing pin starting to make a dent in your primer, you are asking for trouble. Hope that helps.

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Well, my cousin told me he was instructed to discard a round after chambering it in his .40 Glock in the Sheriffs department, and he has never had any military experience.

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I think that the reason would be because every time you chamber the round, it pushes the bullet slightly deeper in the case, eventually causing an overpressure situation.

And TJ, I'm not sure that this applies with 1911's but with most weapons, that action accelerates wear on the extractor.

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thx997303 wrote:

I think that the reason would be because every time you chamber the round, it pushes the bullet slightly deeper in the case, eventually causing an overpressure situation.

And TJ, I'm not sure that this applies with 1911's but with most weapons, that action accelerates wear on the extractor.

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Haven't seen any problems for the 2 or 4 years I've cone it.

TJ

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Yeah, like I said, I'm not sure whether it applies to 1911's but in most cases it causes the extractor to have to flex out to get around the rim of the cartridge, which they don't do under normal circumstances.

As I said, I don't know if it applies to your handgun, If it hasn't hurt it then Great!

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I do not normally need to rechamber the sameround over and over.

But a handful of times to me is not a big deal. I will look at it and unless it has been seated deeper into the casing... I will use it again.

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the only thing I see with that is the round seats deeper only around a thousandth of an inch, I think. I believe that a hundredth of an inch is enough to cause an overpressure. Must check.

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thx997303 wrote:

the only thing I see with that is the round seats deeper only around a thousandth of an inch, I think. I believe that a hundredth of an inch is enough to cause an overpressure. Must check.

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Find it hard to believe...

Seems like it would take more than that to cause the round to be that stuck under the pressure created inside.

Let us know what you find.

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I bought a box of CCI Blazer Brass once and had the only FTF I have ever had with a 1911.

It happened on the 5th round and then again on the 10th round.

It got my attention and so I examined the remaining ammo in the box.

The entire row along one side of the box sat deeper in the foam container than did the rest of the cartridges in the box.

I looked at the cartridges in that row and they were all set visably deeper in the casing than all the others.

They were so deep that the lip of the casing would not allow them to feed, without forcing the slide forward.

I looked at the outside of the box and I could see a wear mark on the box, indicating that the shells had been shipped that way.

I took the remaining shells back to Wal-Mart and they replaced it with a new box.

The row of cartridges were set so deep that they had to be loaded at a significantly higher pressure than were the other rounds, but they did fire without a problem in the 1911.

This leads me to believe in modern weapons, capable of firing +P rounds, that if the round will still feed, that the pressure should not be greater than the rounds I fired that had been seated visibly deeper and would not easily feed.

All that said, when I unload my 1911, I visually inspect the rounds and rotate the chambered rounds so as to not re-chamber the same round, over and over.


Tarzan

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Well I have found a general consensus, particularly with the .40 S&W round, but equally applicable for all rounds, that multiple chamberings can cause an overpressure. SGT Jensen did his own little test on this, the results can be found here

There is another thread on XD talk that goes along with my hypothesis here

I'm going to speak with my uncle, who has been reloading since before I was born, for an "expert" opinion. Also I believe that SGT Jensen reloads, and I will be sending him a PM.

If you read his test, the first time he chambered a round, it seated 3 thousandths of an inch deeper then when measured new out of the box, the second time it seated an additional 2 thousandths, the third time 3 thousandths, the fourth time four thousandths, the fifth time 3 thousandths, the sixth time was 3.5 thousandths, and the seventh time was another 2.5 thousandths. By this time the round was had gone from being 1.120" long to 1.099" long.

Seems like the best bet would be to only chamber a round three times, before you have to shoot it. Just chamber the round, when you unload place that round in a box marked one and add a fresh one. Do this until you run out of fresh rounds, then chamber the ones in the box marked one, and when you have chambered one from that box place it in another box marked 2. And so on until all of your original rounds have been chambered three times, then go out and shoot them, or use them in backup magazines. It should take a long time until you do this unless you unload your firearm every night, which IMO is a no no.

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I unload mine 3-4 times per week to dry fire, trying to work the anticipation out of my routine and trying to naturally smooth out that sticky Glock trigger. I guess I'll need to buy bigger boxes of defense ammo.

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Okay, so after reading this thread I guess I need to get some calipers and measure my rounds. What's the tolerance, the total length of the .45acp is 1.260, how short should I let the round get before discarding it?

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asforme wrote:

Okay, so after reading this thread I guess I need to get some calipers and measure my rounds. What's the tolerance, the total length of the .45acp is 1.260, how short should I let the round get before discarding it?

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I say do it a few times under what would be normal conditions and see if there is any additional seating.

I suspect there will be little to none at all.

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For automatics, I will rechamber the same round 2-3 times, and then after thatI will cordone it off to be shot next time I go shooting.

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I always drop the round into the receiving end of the barrel itself, then relies (sp?)the slide. would that alleviate the seating issue, or am I creating a problem?

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About the extractor thing, the standard 1911 extractor absolutely is not designed to slam one in the chamber without using the magazine. A good one will be able to take it a lot longer than most, but eventually it will, without question, screw up the extractor's tune. It just isn't that hard to use the mag, so I always do.

Exceptions to this include Para Ordanance's newer extractor system, and perhaps some of the external extractors, but I'm not sure about the external ones.