long loaded 40sw ammo/10mm barrel?

[kimberacp]

can long loaded 40sw/180 gr FMJ (1.180) ammo be shot out of a 10mm barrel?

thanks

[Duke Nukem]

No. A cartridge head spaces on the case mouth the 40 is too short so the extractor will be the only thing holding it in place. It will work for a couple shots but the extractor should blow off.

[GuildSF4]

Some have done this and swear that it works fine. Your accuracy may suffer as the case is not indexed off of the case mouth. (Have see it done in glocks and 1911s'.)

[earplug]

I had a 1911 45 ACP with excess head space. My primers would back out until they hit the breech face when fired. Some would deprime themselves and cause a jam.

[kneelingatlas]

It will work for a couple shots but the extractor should blow off.

I'm going to call bullshit here; do you have first hand experience with this phenomenon? The case in definitely not driven forward when fired.

I do have experience shooting 40 in a 10 with no adverse effects on function or accuracy. I haven't fired tens of thousands of rounds this way, but I have talked to shooters on this forum who have shot that many rounds of 9x19 in a 9x21 barrel with no problems.

That being said, the real risk is that the rim slides in front of the extractor and your stage is over.

Edited September 4, 2013 by kneelingatlas

[z40acp]

Back in the 90s I owned a Colt Delta Elite 10mm. I got tired of seeing the 10mm brass travel 20-25 feet. I read about this in a gun magazine so I tried it. First just one shot then two etc.. I once shot a whole peanut butter jar full of .40s out of the Delta. No malfunctions which was more than I could ever say for the Delta with the 10s. It convinced me to buy a Ed Brown .40 barrel. I would not do this in a match or with my life on the line.

Edited September 5, 2013 by z40acp

[kneelingatlas]

I would not do this in a match or with my life on the line.

My sentiments exactly.

[Gandof]

Yeah, I've seen .40 fired in 10mm barrels as well, without adverse effect. If you look at case length tolerances and chamber dimension tolerances, you'll wonder how often a case actually headspaces on the case mouth.

I don't shoot .40 in my 10mm barrel, but some have been known to do so without ill effect.

Gandof

[GuildSF4]

I would not do this in a match or with my life on the line.

My sentiments exactly.

I would agree that this is not the best option.

[10mmdave]

Years ago I did this for a steel match, light loaded 40 S&W brass in a fully supported 10mm chamber,

it worked fine for the whole 200 rnd match, did notice the occasional werid sounding "pop" instead of

a bang but the steel still clanged and the gun still ran !

Later after going through my spent brass I found a number of cases with pierced primers, and then

recalled getting some spit back on my face while shooting this ammo, "Super Face" was the old term

I believe.

Came to the conclusion that yes, you can shoot 40's out of your 10, maybe with the right spring for

lite loads and a good extractor, but, as others have advised, best to get the right chamber for the ammo.

(I did sleeve a 10mm barrel for 40 S&W after this but that's another story )

[Steve RA]

I've shot .45 ACP out of a .45 Win Mag Grizzly without any problem.

[kneelingatlas]

did notice the occasional werid sounding "pop" instead of a bang

Now that you mention it, this is why I stopped shooting 9x19 Major ammo through my 9x21 barrel; it just sounded weird

[jmbaccolyte]

Why not just have your .40 barrel throated for the bullets and O.A.L. you plan to use and run 10mm magazines? Good headspacing, cheap brass, everything but that the 10mm is cooler than the .40S&W. I still hear .40 Short and Weak jokes from guys who remember how it was developed after some of the FBI Agents couldn't handle the recoil of the full power 10mm loads (I think most of them just didn't practice on their own between qualifications.)

Edited September 6, 2013 by jmbaccolyte

[zaphar]

Are there any disadvantages to throating out the barrel? Would you be able to still use regular length ammo? From what I've seen with the 40S&W, you shouldn't have trouble loading a 165gr+ bullet to the same OAL as the 10mm, which would make a conversion like this pretty easy for a EAA Witness/Tanfoglio. You would probably just need to use a 10mm magazine and a heavier recoil spring.

[jmbaccolyte]

I didn't have to throat the barrel on my .40 Witness Match to run 10mm OALs; the factory must save money by using the same barrels in both the .40 and the 10mm and just cutting the chamber lip (or whatever its called) to get the case mouth to headspace the cartridge properly.

Regular .40 length feeds great as long as you use the proper magazines. I haven't tried the shorter cartridges with the 10mm magazines to check the feeding.

[kneelingatlas]

Are there any disadvantages to throating out the barrel? Would you be able to still use regular length ammo? From what I've seen with the 40S&W, you shouldn't have trouble loading a 165gr+ bullet to the same OAL as the 10mm, which would make a conversion like this pretty easy for a EAA Witness/Tanfoglio. You would probably just need to use a 10mm magazine and a heavier recoil spring.

The only drawback to loading super long is you need more powder to get the same PF in a shorter OAL. I don't know if there's a linear relationship between powder charge and felt recoil, but they're definitely a linear relationship between powder charge and money!

[jmbaccolyte]

Yes a very long loaded .40 burns more powder than a normal length .40 for an equal amount of work performed, however the .40 cases are a lot cheaper than the 10mm cases. Especially if you have some law enforcement friends who can help you out with discarded range brass (truly once fired) . Also being able to shoot a minor level load .40 and then swap out the recoil spring for a little stronger one for major power levels and then for a much stronger one and the guide rod for a Sprinco (Nealio's advice) and shoot much more powerful loads is nice.

And its not just the expense of burning more powder, Kneeling, its also finding some.

[Steve RA]

Also consider the novelty points for being different from the rest of the herd !!

[Shadyscott999]

No. A cartridge head spaces on the case mouth the 40 is too short so the extractor will be the only thing holding it in place. It will work for a couple shots but the extractor should blow off.

Not necessarily. There are folks that have been doing just this for years. The extractor holds the case, but the pressure is rearward into the breech face. Same as shooting 9major in a 38 Super/Comp

[Steve RA]

Yes, if you want to mess with it, measure a # of fired .45ACP cases and compare with the SAAMI specs for that cartridge. Hint - you will find 99.44% of them shorter than the specs.

[RH45]

A fellow shooter occasionally runs a .40 through one of his .45s.

Just because you CAN do it, doesn't mean you should.

I wouldn't!

[kneelingatlas]

I got a couple of Glocks mixed up and fired a 9mm round down a .40 barrel...

Made a funny sound, but no I'll effects.

[Steve RA]

I've done it inadvertantly - .40 in .45 - and all it does is launch a projectile slowly, Lord knows where, and totally ruin the .40 case. I can't see any danger in it but doubt it would hurt anything.

[jmbaccolyte]

I've done it inadvertantly - .40 in .45 - and all it does is launch a projectile slowly, Lord knows where, and totally ruin the .40 case. I can't see any danger in it but doubt it would hurt anything.

I assume you're loading fairly mild .40s. I'd think firing a max loaded .40 cartridge in at least some .45 pistols would be more exciting (in a real bad way- like damaged hands, magazine, extractor and maybe frame). Please be careful Steve, I enjoy your comments.

Edited September 9, 2013 by jmbaccolyte

[GuildSF4]

A fellow shooter occasionally runs a .40 through one of his .45s.

Just because you CAN do it, doesn't mean you should.

I wouldn't!

The issue with this is if the case slips the extractor and goes into the chamber and another round is chambered after it. Boom. I have not seen this, have heard of it happening though.