Re-chambering vs direct chambering update 3...

[Tangle]

This came up in another thread and rather than divert that thread any further, I thought I'd just make a new thread on this subject.

The issue is the problem of setback from chambering a round repeatedly and direct chambering that some have opined will lead to extractor failure.

So, why does any of this matter in the first place? Well, for those that never have to unload their carry ammo, either to leave their gun in a vehicle, or unload to shoot, etc., it isn't a problem. But for those who have to unload their gun for what ever reason, especially on a daily basis, we may need to be aware of some potential problems with our methods.

Rechambering and setback:
I personally have tested an M&P, Sig 226, Beretta 92FS, H&K USP, and several 1911s and they all produce setback. In case the term is new to you, setback is when the bullet is pressed back into the case. The problem with setback is it can raise the chamber pressures enough to cause damage to the gun.

While guns can be tuned to minimize, if not, eliminate setback, most of us have out of the box stock guns, and they generally produce setback.

Setback is caused when the round feeds into the chamber. Typically, the slide picks up a round from the mag, drives it forward and the nose of the bullet contacts the feed ramp. That's where the trouble begins. If a round is only chambered one time, the setback is very minimal or may not occur at all. But as we rechamber that same round, things get progressively worse.

Probably most of us load a gun by putting a fully loaded mag in the gun, drop the slide to chamber the top round, remove the mag to insert a round to top off the mag. When we unload the gun, we drop the mag, rack the slide. When we reload the gun, we already have a fully loaded mag so we insert the mag, rack the slide (if it's not already locked back) and the top round is chambered. The mag is removed and that loose round is inserted in the mag to top it off. This process rechambers the same two rounds, every other time of course, everytime we reload.

If we do this daily, for two weeks, each round has been rechambered 7 times! I.e. the two rounds have been setback 7 times! From my tests, the rounds seem to hold up for a chambering or two and then they really start to move.

One alternative is to rotate all the rounds through the mag, but that is a bunch of trouble. The mag has to be completely emptied every day, so the last chambered round can be put on the bottom of the stack. But that really just postpones the inevitable.

Direct chamber loading:
Direct chamber loading completely eliminates the setback issue, so rounds can be chambered this way over and over again with no setback whatsoever. Here's how that works:

Starting with a fully loaded mag and one extra, loose round, the slide is locked back and the loose round is dropped into the chamber. The slide is then dropped. This is where some contraversy occurs. Some say that this is hard on the extractor because it forces the extractor out over the rim of the case and doing this will eventually break or damage the extractor.

However, if you look at the loading instructions for a Beretta 92FS and PX4, you will see this loading method described as a viable loading method and there is no indication that it is harmful to the gun. I have been using this method for quite a while with my Sigs and have seen no ill effects. But to be sure, I called Sig Sauer and asked them about this issue. Without hesitation, they said there was nothing harmful about it and even said that the direct loading method was used by many people as a way to have a full mag and a chambered round in the gun.

So what we know is that chambering a round from the mag will produce setback in most guns. So it would be a bad idea to chamber the same round more than once or twice using this method.

We also know that the direct chamber loading method will not produce setback, allows rounds to be chambered many times safely, and is fine for Beretta 92FS, PX4, and Sig handguns. That does not mean it is ok for all guns. So before you use this method, you should talk to the manufacturer of your gun.

[DefensiveCarry.com]

[HotGuns]

The only negative thing I've heard about direct chambering is the fact that it may cause an impact shift from the first round fired due to the chambering pressure being different.

In reality, since we are using handguns, the difference should'nt matter much. The worst example I've seen is a Colt Government Model, it consistently shot the first round much higher when chambered as such, as much as 6 inches at 25 yards. The rest of the rounds were where they were supposed to be.

It does make a difference on rifles and can be somewhat dramatic. Some rifles do it and some dont,I would guess the slop in the chamber being the difference there.

I mostly carry Sigs, I've been using the direct chambering method for years.

Thats a good article there Tangle.

[Cap'n]

Great info Tangle.....since I own and carry a Beretta 90Two. I've never direct chamber loaded....always from the mag and am aware of setback problems. I too had read about direct chamber loading in the Beretta manual but it seemed the norm to load from the mag. Good to here from someone that has actually tested the direct chamber vs mag loading and found it to not be a problem with the Beretta or Sig pistols.

[NCHornet]

As I replied to in the other post, this form of reloading has never been taught to me as being a good idea and I have read, and been told verbally from many gunsmiths that this is a very bad idea. If you load a round this way you are not allowing the ejector to come in contact to the casing in the normal fashion, which is as the round is being loaded. Instead the ejector is being slammed into the back of the casing and being forced over the rear of the casing. If this sounds okay to you than by all means proceed. I was simply trying to pass on the info as I have been told by many quality smiths.
NCH

[Tangle]

NCH,

This has been batted around long before you were here so it wasn't directed at you in any way.

But it is clear that at least Sig and Beretta are good by this method and I believe it is a far superior method than rechambering a round from the mag.

What the gunsmiths said may have been true, and they may have assumed it was true for all guns. While I respect gunsmiths, they don't do the volume testing on guns that manufacturers do or that the masses of owners do. I also know for a fact, that things get started that aren't true and become true simply because it is repeated and handed down.

It's not a matter of it sounding ok, it's a matter of the manufacturer being familiar with the method and approving it. What Sig does not approve of is chambering a round from the magazine more than once. This came up on the Sig Forum and I mentioned this in another post. Sig will not honor a warranty if they think the problem was a result of a round that was chambered more than once. But they endorse/approve direct chamber loading as a kinder way to load the chamber.

As I see it, we only have two choices. Do what the manufacturer recommends or not. Sig does not approve of chambering a round from a magazine more than once and does approve of direct chambering.

[Tangle]

The only negative thing I've heard about direct chambering is the fact that it may cause an impact shift from the first round fired due to the chambering pressure being different.

I've heard the first shot impact shift too. As you said, you can kinda understand it in a precision rifle.

The version I've heard is there is an impact shift even when chambering by hand from the magazine because that is different than the way the gun does it during it's firing cycle. I shoot between 100-200 rounds a week. I can say that I have never seen an impact shift from the first round no matter how I load it.

Until someone can put a gun in a Ransom Rest and show us there's a difference in impact between loading the gun by hand and gun's cycling action, I think we have reason to doubt this claim.

[HotGuns]

Now that would be interesting.

With a gun in the Ransom Rest, chamber it using the magazine and fire a shot.
Several times so as get a respectable shot group.

Then by using the direct chamber method,several times and then comparing the groups.

Of course, it would have to be done with different types of guns. Some might not see any shift in impact, others might.

[TheSamurai]

over at the HKPro forum they're all highly recomending against direct chambering. it's nice to see something opposing it. Tangle, have you spoken with HK to see what they suggest? personally, i keep mine loaded at all times unless i'm cleaining it. in that situation it woudn't get rechambered but maybe once.

[ev239]

Wow, thanks for all the info Tangle. I had never really heard of setback, though I usually direct chamber my +1 mostly because shoving that last round in a mag is not nearly as easy as dropping it into the chamber.

[ExactlyMyPoint]

Anyone know what Glock says about it?

[Supertac45]

I leave my Sigs chambered and if I download a 1911, I only rechamber twice with the same round prior to tossing it to my range ammo. No problems so far.

[Tangle]

Now that would be interesting.

With a gun in the Ransom Rest, chamber it using the magazine and fire a shot.
Several times so as get a respectable shot group.

Then by using the direct chamber method,several times and then comparing the groups.

Of course, it would have to be done with different types of guns. Some might not see any shift in impact, others might.

It would be interesting! I think the snag is gonna be the cost, not only for the Ransom Rest, but each gun has to have a set of adaptors and they are pretty expensive themselves. But wouldn't you love to see what would happen!

[Rustynuts]

If you're so worried about re-chambering and setback, just ease the first round into the chamber. i.e. use slingshot method, but don't let go, just slowly let the slide forward and watch as the round magically goes into battery. May need a little coaxing up the ramp, but you're not slamming it into anything. That's where setback occurs. Once the round is properly in battery, it doesn't care if you used the slide release, slingshot method, or eased it in!

[Tangle]

over at the HKPro forum they're all highly recomending against direct chambering. it's nice to see something opposing it. Tangle, have you spoken with HK to see what they suggest? personally, i keep mine loaded at all times unless i'm cleaining it. in that situation it woudn't get rechambered but maybe once.

Well, I wanted to post facts that come from the manufacturers themselves. So what I've posted is not opinion, but recommendations and approved methods from Sig and Beretta. As I said in the embolded text in my OP, I only know for Sig and Beretta.

The interesting thing about a USP (H&K) is it has an external extractor and you can chamber a round, push in on the rear of the extractor and slowly lower the slide and it's a very gentle operation. It's one of the few guns you can do that with.

But, no, I have not talked to H&K about this, but I'd be glad to call them Monday when they re-open. I'm very curious now to see what they say.

[Tangle]

If you're so worried about re-chambering and setback, just ease the first round into the chamber. i.e. use slingshot method, but don't let go, just slowly let the slide forward and watch as the round magically goes into battery. May need a little coaxing up the ramp, but you're not slamming it into anything. That's where setback occurs. Once the round is properly in battery, it doesn't care if you used the slide release, slingshot method, or eased it in!

If you do that with an M&P, the nose of the bullet will dig into the feed ramp and hold the slide open. The guys on the M&P forum kinda took me to task over that claim, until one of them tried it and got the same results.

But that is true, most guns seem to work the way you described, but I would still ask why chamber from the mag? It's significantly more trouble and more complicated than direct chambering. Direct chambering allows you to keep a mag completely loaded and you never have to remove or re-insert a round into it, in order to have a fully loaded gun.

Every time the round is forced out of the magazine, under the full force of the mag spring, the mag lips score the round and possibly score the bullet itself. Other than that I have no problem whatsoever with the method you described and I have used it myself and that is the method I use if for some reason I can't do a direct chamber load.