Will a .45GAP fit in a .45ACP?

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T.Stahl

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Will a .45GAP fit in the chamber of a pistol designed for the .45ACP?
And what is the working pressure of the .45GAP compared to the .45ACP?

The reason behind asking these questions is that usually the cartridge with the higher pressure will not fit in a gun designed for the lower-pressure cousin (like .38Spec+.357Mag, .44Spec+.44Mag, ...).
What if shooting a .45GAP in a .45ACP would be potentially dangerous due to higher working pressure, wouldn't Glock be risking a lawsuit?
 
Well, I can't speak for autopistols, but I've fired .45 GAP in the cylinder of a .45 ACP S&W 625, and using moonclips, it functioned just fine. I would think that a lot depends on the extractor, as the .45 GAP has a slightly different rim, IIRC, to the .45 ACP. Also, if your chamber headspaces on the shoulder of the cartridge (some do, some don't), you're SOL, as the shorter .45 GAP won't headspace at all - malfunction city!
 
Yes, you can fire a .45 GAP cartridge in a pistol chambered to use the .45 ACP, but there is no good reason to do so, and the performance is likely to be unreliable. You can duplicate .45 GAP ballistics in commercial .45 ACP rounds if that's you're intention.

Unlike revolvers, pistol cartridges do not headspace on the rim. Therefore always use the correct ammunition, not something else.

Preacherman:

We have (or had) a thread running where a member tried using mooncliped .45 GAP rounds in his revolver, but had trouble with a misfit between the clips and the extractor groove in the Glock cartridges. So he tried trimming regular .45 ACP cases to GAP length, and found that it worked better and claimed it made a substntial difference in speed reloading. You might try this.
 
No, my question is not "is there a good reason to do this", but more "is it a wise decision by Glock to promote a cartridge of maybe higher pressure that will easily fit in guns intended for cartridges of a lower pressure."
 
In terms of liability it is less risky than .45 Super (which is much higher pressure and will chamber and fire in 45 ACP guns) or the "Ruger and Contender only" 45 Colt loads of companies like Buffulo Bore, et al.

It is the gun owners responsabilitly to use the the correct ammunition that their gun was designed for and it is not the mfg responsability to make it more difficult to make mistakes, although plenty of people will try to blame them and plenty of counter jockies will pass on, potentially dangerous, misinformation.
 
T.Stahl:

Colt model 1892 "New Army revolvers had chambers that were bored straight through, and they could chamber a .357 Magnum cartridge, although one of those could blow up an old black-powder revolver. This did cause S&W and the cartridge companies to issue warnings, but it didn't stop them from developing and marketing the .357 Magnum. Do you think this was wrong?

The purpose of the .45 Glock Automatic Cartridge (GAP) is to provide a way to have .45 ballistics in smaller guns. While it is not proper nor smart to do so, firing GAP ammunition in any good-quality pistol chambered in .45 Automatic Colt Pistol (ACP) is unlikely to damage the gun.

I suppose there are some rather stupid people that will fire the wrong cartridge, regardless of any warnings. But I see no reason Glock should be held responsible for what they do.
 
.45 Auto and .45 GAP headspace on the casemouth, not the case rim.
Like shooting 9mm Parabellum in a 9mm Largo Astra 400 it will kinda , sorta work but no good will come of it.
 
.45 ACP has a max of 21,000 PSI for standard pressure, 23,000 PSI for +P. .45 GAP has a standard pressure of 23,000 PSI, and I'm not sure if there are any +P loadings for it yet.

So assuming nothing goes wrong due to the case dimensions, a +P capable .45 ACP handgun should handle GAP safely. That's too big of an assumption to make, of course.
 
You're right, but the long ACP chamber would act as a freebore and drop the pressure.

The GAP is considered to be a plus-p load from git-go. I don't think they will come any hotter.
 
Funny I posted a question about this on sigforum a while back. Here is why I was interested:

Long story short I was going to take a very goog friend to the range to shoot my 1911 and show him why I love the design. Some stuff came up and I couldn't go, normally I would never lend a gun to anyone, but this guy is the closest thing I have to a brother and I trust him. So after about 45 minutes of instruction on how to safely handle the 1911 I sent him on his merry way.

Here is the problem. He has shot 9mm all his life, and never handled anything chambered in .45ACP. Well I told him to get Winchester whitebox in .45ACP and have some fun. The place he went to didn't have any Winchester .45ACP and the idiot behind the counter sold him box of Speer 200 grain 45GAP! My friend didn't even know there was a difference since he only shoots his Glock 17 and the military M9.

Anyway, when he returns he tells me my gun is a jammo-matic and he can't understand why I like the thing. He said he tried to shoot 5 mags (40 rounds) through it and when he got a shot off it was nice, but jammed almost every single round. He hands me my gun, and the box of Speer Lawman 45GAP with 10 rounds left. I thought my head was going to explode, jams and all he had shot 40 rounds through it with the wrong ammo!

Anyway, after that long explanation does anyone know if any damage was done to my pistol due to this fiasco? If so what needs to be done to fix it before I shoot it again?
Click to expand...
http://sigforum.com/eve/ubb.x?a=tpc&s=674608412&f=430601935&m=38060094&r=38060094#38060094

I have not found any problems with the gun since then, but I am considering replacing the barrel just to be safe. Currently it's disassembled as I'm upgrading it a little.
 
DMF

There is no good reason to go to the expense of replacing the barrel. While shooting the shorter .45 GAP cartridge cause all kinds of malfunctions it didn't do anything to the .45 ACP barrel that a good cleaning wouldn't take care of. Contrary to what some think, the Glock cartridge does not generate excessive pressures in an ACP barrel.

Using the wrong cartridge has been a problem for al long time before Gaston Glock came along. For example too many ignorent or badly informed people have loaded up old 1903 .38 Colt automatics (designed to use the .38 ACP cartridge) with .38 Super - which is a big no-no. Yet most of them didn't suffer any serious consequences. I once had an owner of a Walter PPK come to me and complain about it jamming. He was using .32 S&W rounds, not .32 ACP that some shop had sold him. Again, no damage to either the gun or shooter.

So put your (his) .45 back together and use it - but with the right ammunition.
 
The .45Gap won't cause any problems based on pressure alone.

The problem that COULD happen will be a result of the grossly improper headspace that WILL occur IF the extractor doesn't hold the cartridge against the breechface. It might be possible for the firing pin to hit the primer of a case not help by the extractor.

Even if this were to occur the locked breech design of a typical .45acp pistol SHOULD contain all of the mayhem. But it might not. It will definaltely be hard on the extractors.

The real danger will be if the primer exits the case before recoil can slam it back against the breech face.
If you blow a primer you might as well kiss your grips goodbye.
And hopefully you will be wearing eye protection.

The best advise I can conjure up regarding shooting .45 Gap in a .45 ACP pistol is. JUST DON'T DO IT!
.45Gap does NOTHING that .45acp can't do. And .45acp is cheaper.
 
Of course you should use the proper ammo for the gun - and so would I.
But I guess most of the .45GAPs will be sold in the US, where you might sue the maker of your micro-wave because it fried your cat.
Anyways, it seems the operating pressure of the .45GAP isn't that much higher than the .45ACP's, reducing the chance for a kBoom.

Ok, questions answered. Thank you!
 
Fill the Gap

The GAP's slightly higher pressure isn't the potential trouble spot. .45 ACP
caliber pistols are proofed at around 25% higher pressures than SAAMI
averages...which would put it into the neighborhood of 25-26,000 psi.
The problems will come from the headspacing of the GAP round in even a minimum .45 AP chamber. If the round headspaces on the extractor, it will fire...and probably function the gun. If it doesn't...and the case slips forward
to headspace on the shoulder...the primer will probably blow out of the pocket and send hot gasses into the breech area with unpredictable results.
The extractor won't have a grip on the rim, and even though the case MIGHT
exit the chamber from residual pressures...it can't be counted on.

Too much room for Murphy to crash this particular party. Don't do it!
 
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