Rechambering the same round

[DeepSouth]

I have been told in a semi-auto pistol if you rechamber the same round enough it can force the projectile back into the casing causing possibly dangerous high pressures. OK, so it sounds reasonable and logical but for Pete's sake how many times can I rechamber the same round and still be safe? 1, 2 ,3 4,

I need to know, I use my CCW to plink with a lot so I would break the bank if I changed out a Gold-Dot every time I rechambered it, or every 10th time for that matter. BUT I'd rather be safe than cheap.

So long question short, How many times could you rechamber a .45 in to an auto loader before needing to replace it with a 'fresh' one?

Thanks in advanced.

DS

 

[Gamera]

Interesting question, I'd like to know the answer to that as well!

 

[jcwit]

I side with Gamera in wanting to know the answer. However I believe it would more than likely be a problem with handloaded ammo than favtory rounds. But we shall see..


RC where are you.

 

[ScareyH22A]

There's more forces applied to ammo inside the magazine during recoil. I wouldn't worry about it. Plus, if you chamber slowly by riding the slide, you can see that the bullet gets tilted up so there really isn't much force exerted to the bullet.

 

[AK103K]

You will eventually experience set back, even with factory ammo. If you mike the rounds when you first load it, and continue to do so after subsequent loadings, you'll see a difference.

I used to carry Federal Hydra Shoks in my .45's when my kids were small, and I unloaded my pistol each night and reloaded each morning, and I usually took the top round off the the mag once a week. The difference in OAL between it and the next round in the mag was obvious when set on the table side by side. The top rounds cavity mouth was also deforming pretty well at that point, and the lead was usually starting to roll away from the jacket.

These days I carry a 357SIG, and just leave the gun loaded and shoot the mag in the gun empty about every other week.

 

[SuperNaut]

See THIS thread.

I'm planning to test this out once I find an inexpensive pistol.

 

[Steve C]

Setback can be a problem with some ammo and in some pistols. Some brands are so heavily crimped or are a 100% powder densitiy to begin with that you can chamber them any number of times without any noticeable set back.

Simply look at your ammo that's been fed and ejected and compare it to a round that hasn't been chambered. If the bullet has been obviously set back and you're worried about it then swap it out. IMO you want the short round in the spout as you are more likely to get proper feeding from rounds that haven't been made shorter. I've shot plenty of shortened rounds due to set back without problems on subsequent rounds or any sign of over pressure.

FWIW Gold Dots can be some of the most susceptible to set back in my experience as some of the ones I've used haven't been crimped as tightly as other ammo and the wide nose profile seems to catch on the feed ramp easier than other brands. Again, dependent on the gun and magazine.

 

[DeepSouth]

So, would you say to inspect, even measure the rounds every now and then and as long as there ins't a significant difference everything should be fine.

That just makes to much since, and sounds to easy. Not to mention I now feel pretty stupid for not thinking of that myself.:banghead:

 

[herohog]

When a round has been used a few times, mark it with a Sharpie marker and cycle it into a position other than the top round and you are good to go. I do this all the time.

 

[1SOW]

Steve C +1

It shouldn't be a big problem to inspect & mic it occassionally.

Sig 357 is mentioned on some reloading sites as susceptible to set-back problems from rechambering. http://reloadammo.com/ (Reloading Pages of MD Smith)

 

[AK103K]

Sig 357 is mentioned on some reloading sites as susceptible to set-back problems from rechambering.

It might be an issue with a load that doesnt fill the case, but if you use AA #9, or even #7, the case is pretty much full, or the load even compressed.

I havent had an issue either way, and the crimps alone seem to hold fine.

 

[GodGuns&Guitars]

When you slam the slide home on the same round repeatedly it will eventually "turtle." Yes, it will slide deeper into the casing. Happens a lot with loosely crimped rounds. Good reason to cycle your carry ammo, shoot the old up and replace with new. Cycle the ammo in the mag a lot too. Don't shoot these rounds. Pull them and reload them, throw them away, but don't shoot. Rounds that turtle can become compressed causing extremely high pressures.

 

[hillbillydelux]

I decided to see just how much a bullet will recess after multiple chamberings. I used a Springfield 1911.

- Speer lawman 230gn FMJ. Started at 1.260 after chambering 5x 1.258 10x 1.257
no big deal

- Speer 230gn gold dot. Started at 1.245 after chambering 5x 1.230 10x 1.227
Definatly some movement

- My handloads 230gn XTP. Started at 1.245 after chambering 5x 1.238 10x 1.235
Some movement but not really signifigant

So in this particular gun it seems the hollow points compress more than round nose. Obviously it takes more force to jam the hollow point up the feed ramp and into the chamber.

So yes it is possible after many chamberings to compress the bullet into the case a signifigant amount. Probably would not be a big deal in the .45 but could cause some problems in smaller high pressure rounds like 9mm.

I will definatly start measuring the rounds I chamber more than once.

 

[Mike J]

I might be wrong but I think this is more a problem in the .40 because it is such a high pressure round.

 

[Cactus Jack Arizona]

Well, this really is a very interesting question that I never would have thought about if not for this thread. However, I don't worry about this because, as I have stated in a previous thread, I do not carry chambered. Very interesting read, all the same.

 

[Bullet]

Taper crimp does NOT hold the bullet. The case tension does.

Measuring your cartridges after chambering only tells you what the OAL is now, not what the OAL will be the next time you chamber it.

If you have to rechamber your cartridges I’d recommend you chamber slowly by riding the slide as stated above.

 

[Elvishead]

Maybe if it's an issue with you, couldn't you chamber it with your fingers?

Put an empty mag in, and rack it open, then with your fingers put in the round.

Not that I would bother, I just shoot the chambered round when I get to the range.

 

[The Lone Haranguer]

Inspect the round after each chambering and discard it if it becomes excessively "telescoped," extractor groove dented/nicked, etc.

 

[tex929rr]

Much more of a risk with .40 than with .45 ACP. I have fired untold numbers of reloaded .45's with nary a problem. But I did have a .40 round destroy a P99 (no harm to the shooter) - my conclusion after was that a round had been rechambered and that this caused my problem. I wasn't shooting so I can't be sure.

 

[gwnorth]

I've seen it with my guns a couple of times. But, I would say it will vary a lot with the ammo and the gun being discussed. In other words, there is no set rule or pre-determined number of times. All you can do is check a previously chambered round against some of the same stuff that is fresh out of the box. If it looks okay, re-chamber it.

In my Taurus PT1911, I've seen setback with rounded profile JHPs (eg. winchester silvertips) after just a couple of chamberings. JHPs like Hornady TAP, which are more cone shaped in profile, do not seem to be prone to it in the same gun. Neither shape of round has shown any setback in my FNP-45 even after 5 or 6 chamberings. For 9mm JHPs I mostly have 124gr Speer Gold Dot and have not seen any setback with those (SIG P226 and a CZ P-01), but did notice it once with a Federal Hydroshock after several re-chamberings.

As they say, YMMV, so all you do is check your ammo before re-chambering a round, just don't assume anything.

 

[AK103K]

You basically have two choices here, keep an eye on it, or dont unload the gun. The later is the easiest solution if its a viable one for you.

 

[strangelittleman]

It can be a problem, there is an article on the web somewhere about the security force at a Nat'l Lab that had a kb w/ a service pistol due to set-back.
In my dept there is an official memo urging all staff to inspect their ammo periodically. I have noticed with our pistol/ammo combo (M&P40/Rem 180grJHP) that it takes about 20-22 rechamberings to get a significant set-back that makes me uneasy enough that I switch it out.

 

[Bullet]

Maybe if it's an issue with you, couldn't you chamber it with your fingers?

Put an empty mag in, and rack it open, then with your fingers put in the round.

If you do this you will not have the brass under the extractor as it would be if fed normally. When the slide is released the extractor has to ride over the brass to get in the extraction groove. This can hurt the extractor in some guns.

 

[jigglyjames29]

I remember looking at data on GlockTalk. Sometimes the OAL would be LONGER after many chamberings.

 

[rcmodel]

Take a black Sharpie pin and mark around the bullet / case joint on your new ammo.

Very easy to spot one with setback after that.

rc