10 mm Pistol Questions

[dgludwig]

I recently purchased a S&W Model 2.0 pistol chambered in 10 mm. The instruction manual included the following safety admonition in red and in all caps: "WARNING: ALWAYS LOAD A ROUND INTO THE CHAMBER BY FEEDING IT FROM THE MAGAZINE. FAILURE TO FOLLOW THIS WARNING CAN RESULT IN SEVERE INJURY OR DEATH TO YOU OR OTHERS. NEVER ATTEMPT TO LOAD THE PISTOL BY INSERTING A ROUND INTO THE OPEN EJECTION PORT."

This caveat would seem to obviate the supposed advantage a pistol not equipped with a magazine disconnect has in that if you should lose the mag you still can fire the gun albeit even if only limited to one shot at a time.

Secondly, I'm wondering why the CCI Blazer 10mm, 200 grain FMJ carton has the following warning: "Do not use in carbine style firearms. Use in carbine rifles can result in firearm damage and/or serious injury."

Any thoughts or opinions? Thanks.

[Jim Watson]

You will just have to make extra preparations for all that extra power. At least two spare magazines.

Aluminum Blazer?
Most PCCs are blowback and aluminum does not have the stretch and spring back of brass. Aluminum .357s not so hot in lever actions, either.

[RickB]

Does the pistol have a mechanical firing pin block; concern that the firing pin could strike the chambered round?
Or, concern that a round not dropped fully into the chamber could discharge if struck by the ejector?
Carbine-style firearms that have no firing pin return spring might set off a round if you . . . insert a round in the chamber and then drop the bolt?

[wild cat mccane]

Probably because Blazer is mechanical the crappiest junk made.

Used to state no use in a comp gun. The "copper" fmj is the idea of copper and that's it. The copper wash could be ripped off at comp. Imagine it would be same at higher fps barrel length.

On the warning, you are confusing a mag disconnect as the same as loading from the chamber. Out of battery fire or broken extractor piece into the chamber onto the loaded primer isnt a mag disconnect issue. Not the same parts.

[JohnKSa]

It's actually kind of unusual for a manufacturer to give the ok for direct chamber loading. Mostly they want you to load from the magazine. That's usually a function/durability issue, not one of danger, however.

I suspect they are concerned with the ejector possibly hitting the primer and setting the round off without being chambered and that's what the danger warning is about.

As far as the warning about carbines, again, this is speculation, but I'm guessing you were looking at Blazer aluminum cased ammo and the warning is oriented towards blowback operated carbines. I can't think of any reason why a locked breech carbine should be unsafe to fire with any 10mm ammo that is safe.

[Shotgun Slim]

A case could be made that dropping a round into the chamber then closing the slide could result in extractor damage or breakage but that would apply to all semi autos,not just the 10mm.

[Ricklin]

Breaking an extractor does not result in serious injury or death, at least not to the shooter, perhaps they are speaking of the gun?

[44 AMP]

There are a number of reasons why putting a round in the chamber and then letting the slide/bolt slam shut on it is a bad idea.

The "risk of injury or death" comes from the fact that certain designs can accidently fire if you drop the bolt on a chambered live round.

The .44 Auto Mag has a specific warning to never do that in the owner's manual.

The reason is exactly that, because the bolt slamming shut on a live round in the chamber is moving faster than its designed to do, and the floating (inertia) firing pin could fire the round. (without pulling the trigger or the hammer falling!!) Also there is the possibility of the round fired in this way going off before the action is fully locked shut with dangerous consequences.

Other possibilities, (depending on gun design) are damage to the extractor, and/or driving the chambered round deeper into the chamber, which can result in increased pressure (possibly dangerously increased) if the round fires. And then there is also the possibility of the round being driven too deeply into the chamber for the firing pin to fire it, and being in front of the extractor, so no way to extract the round, which can be another whole level of bad thing depending on the situation.

Some guns are designed and made so that you can drop a round into the chamber and let the slide/bolt slam shut on it, and nothing bad happens. Others are NOT. Some of those will tolerate it being done once in a while, without issue, others won't. Whether its a gun, or ammunition (or nearly anything else) if the maker says "Don't do that" then DON'T DO IT!!!

This caveat would seem to obviate the supposed advantage a pistol not equipped with a magazine disconnect has in that if you should lose the mag you still can fire the gun albeit even if only limited to one shot at a time.

It might seem to, but it doesn't. The advantage is still there. You can still load and fire the gun, without a magazine in place, one round at a time. What you shouldn't do is drop the round into the chamber and let the slide slam shut on it. The way you do it is simple, but requires a little bit of dexterity and the knowledge not to do it the other way.

You just fit the round to the breechface, making sure its in the right position, and under the extractor, then EASE the slide shut. Make sure its all the way shut (by pushing it shut if needed) as you can't rely on the recoil spring in that situation. Yes, it takes more time and effort than just dropping a round into the chamber, but it will work, and work SAFELY if done right.

And, yes, you're out of the rapid fire business, but you gun will still fire its just slow to reload. This does not happen with a pistol that has a functional magazine disconnect. If the mag isn't in the gun, in its proper place, the gun will not fire when the trigger is pulled.

Some tout this feature as there have been documented cases of it saving lives. The problem is, there is no way to measure that against cases where it cost lives, which I'm personally sure it has, but there's no data to support that available, that I'm aware of, anyway.

Secondly, I'm wondering why the CCI Blazer 10mm, 200 grain FMJ carton has the following warning: "Do not use in carbine style firearms. Use in carbine rifles can result in firearm damage and/or serious injury."

Any thoughts or opinions? Thanks.

For this, you should ask CCI. My guess would be a combination of the 10mm pressure, case length, aluminum case and the blowback action of semi auto carbines in pistol calibers.

What works well enough in locked breech, standing breech actions doesn't work as well in semi autos, and with aluminum cases, both pressure and case length seems to be an important factor. Short rounds like 9mm and .45acp do well enough, longer rounds like .357 do not. Possibly 10mm is long enough to have issues because of that.

Personal experience, firing blazer (aluminum) .357 in revolvers works fine. Same ammo fired in a semi auto (Coonan, Desert Eagle and LAR Grizzly) tears up the rims, extractor ripping through the case rim, or sometimes even ripping the case head off. Its not a happens 100% of the time thing, but it does happen, and often enough to make the ammo unsuitable for those particular guns.

[Pumpkin]

I think 44AMP nailed the 2.0 safety issue by saying the round could driven past the point of the chamber headspace step causing chamber pressure to spike.

I believe I have an older Speer or Hornady loading manual that cautions using max loaded revolver rounds in a lever action.

[4V50 Gary]

Somebody please write CCI and ask them.

[gwpercle]

Heed the Warnings !

They are there to protect you from injury ... Dont be acting the fool .
Gary

[Jim Watson]

If I am in a gunfight and nothing left but loose cartridges, the extractor will just have to take its chances while I do. But I wouldn’t be carrying aluminum ammo to start with.

[Aguila Blanca]

Originally Posted by Shotgun Slim

A case could be made that dropping a round into the chamber then closing the slide could result in extractor damage or breakage but that would apply to all semi autos,not just the 10mm.

This is why it's not recommended to load a round into the chamber of a 1911 and then drop the slide, but the 1911 uses a solid, spring steel extractor and the potential issue is breaking or fatiguing the extractor. Most modern semi-automatics (including a couple of brands of 1911) use an external, pivoting extractor with its own spring, and breakage should not be a problem.

[glider]

I think what they are concerned about is closing the slide on your finger LOL! Really, that would be bad with that strong recoil spring!

[44 AMP]

Really, that would be bad with that strong recoil spring!

This is why stupid should hurt!

As the owner of several pistols firing magnum class rounds, having recoil springs much stronger than regular service pistols, to feed rounds that are larger and longer than standard service cartridges, keeping my fingers out of the way when the action cycles is not something to be ignored! :eek

I do rather doubt that the primary concern letting the slide/bolt slam shut on a chambered round is the risk of one's finger being in the way. Certainly it would be a bad thing, and hurt ALOT! But it is entirely a user controlled action. Don't put fingers, or anything else in the way of moving metal and they won't be hurt is a pretty sound general rule. Break it at your own risk!

[Pumpkin]

dgludwig,
So I found my owners manuals for my 9mm and 40 2.0’s.

On page 18, in Red, they say the same thing about loading a round into the chamber and releasing the slide on it.

Sounds like a design characteristic of these pistols.