BJung
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My younger brother shoots .40 S&W through his 10mm. I still think he's crazy but he's been doing it for awhile. Does anyone else do this?
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Mark_Mark
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I heard it’s not good because the case is moving in the chamber.
LiveLife
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Many of us are technically doing the same with our semi-auto loads and not realizing it.
As brass gets repeatedly reloaded, it gets shorter and eventually will start headspacing off extractor with bullet nose/case mouth dangling away from the chamber and if you reload same brass long enough, most of your rounds are not headspacing off case mouth rather extractor. Same thing happens with 40S&W round headspacing off 10mm extractor and dangling away from chamber/start of rifling (Albeit with lower powder charge than intended ... So you are shooting very "light" 10mm target loads
).So do we worry about shorter brass headspacing off extractor? Not me.
Maybe a little as 40S&W round is held against breech wall face by the extractor. I thought about shooting 40S&W when I got my 10mm Glock 20SF as I have a bunch of 40S&W brass. I guess if I wanted greater accuracy, I would use 10mm-40S&W conversion barrel.
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Mark_Mark
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I like the .40 barrel on a 10 idea!Many of us are technically doing the same with our semi-auto loads and not realizing it.
As brass gets repeatedly reloaded, it gets shorter and eventually will start headspacing off extractor with bullet nose/case mouth dangling away from the chamber and if you reload same brass long enough, most of your rounds are not headspacing off case mouth rather extractor. Same thing happens with 40S&W round headspacing off 10mm extractor and dangling away from chamber/start of rifling (Albeit with lower powder charge than intended ... So you are shooting very "light" 10mm target loads
So do we worry about shorter brass headspacing off extractor? Not me.
Maybe a little as 40S&W round is held against breech wall face by the extractor. I thought about shooting 40S&W when I got my 10mm Glock 20SF as I have a bunch of 40S&W brass. I guess if I wanted greater accuracy, I would use 10mm-40S&W conversion barrel.
Shooting 40S&W in a 10mm barrel means the bullet has to jump a bit of 'free space' before entering the rifling. I don't know the impact of that on accuracy, as I have never done this. Also, I would suspect that the ridge at the end of the chamber would get contaminated shooting short rounds through it and may cause problems when trying to shoot a full-length 10mm round. But again, I have no experience with this scenario. I have fitted 40S&W barrels for both of my 10mms and just switch barrels depending on what I want to shoot.
Trey Veston
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I bet he also shoots .38 special in a .357 Magnum handgun as well. The horror. People have been shooting .40 S&W in 10mm handguns for decades, and I have never seen or heard of a single problem.
The "experts" like to chime in and say it's awful and will lead to problems, but I've never seen any of them offer an actual real-life example of damage or harm to a pistol from doing it.
The "experts" like to chime in and say it's awful and will lead to problems, but I've never seen any of them offer an actual real-life example of damage or harm to a pistol from doing it.
CoalCrackerAl
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I broke the block on my Stevens crack shot. From shooting 22 shorts in it. The breech was carbon-ed up. And when i shot 22 lr. It did the damage. That's what the gun smith told me after he replaced the block. Learned my lesson now. To clean all my 22's after shooting shorts. Same with my 357's after shooting 38's. As for 10mm. I down load some when i want a softer shooting round. My Ruger black hawk. Has a cylinder for 10mm and one for 40sw.
loadedround
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You are aware that both cartridges headspace on the case mouth? Foolish thing to do in a semi auto pistol. I wouldn't do in either of my pistols since cases are so cheap and plentiful.
tominboise
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I have a G20 and I bought a 10-40 barrel for it. Works great and shoots very accurately. Everything feeds fine from the 10mm mags. The gun shot so well with that barrel that I bought the same brand barrel chambered in 10mm. It also feeds fine and shoots great.
Another advantage of the aftermarket barrels is a more fully supported chamber and "normal" rifling that allows the use of cast bullets in the Glock.
Another advantage of the aftermarket barrels is a more fully supported chamber and "normal" rifling that allows the use of cast bullets in the Glock.
LiveLife
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Only if you are shooting new factory ammunition and reloads with brass that's been reloaded limited number of times. Brass case length gets shorter as reloaded repeatedly which is a well known fact.
As brass case length gets shorter, chambered rounds stop headspacing off case mouth and starts to headspace off extractor (To check, chamber reloaded rounds in barrel. If case base rim is below the barrel hood, the round will headspace off extractor). I don't think reloaders will stop reloading shorter length cases as most of them likely won't know when their brass case length gets short enough to start headspacing off extractor.
As I mentioned in Post #3, use of 10mm-to-40S&W conversion barrel will allow less gas leakage/more consistent chamber pressure build for better accuracy but I do not believe shooting 40S&W in 10mm will damage the firearm. Like shooting .38 Spl in .357 Mag ... No damage, but perhaps more cleaning. (And I shoot copper plated/washed 22LR in my .223 ARs with CMMG conversion bolt ... And no damage, just a bit more cleaning of fouling from blowback action)
I am actually doing a "myth busting" thread on longer vs shorter 9mm cases that no longer headspace off case mouth in the "Handloading & Reloading" subcategory and will post my findings in a new myth busting thread - https://www.thehighroad.org/index.p...ngth-and-accuracy.901574/page-2#post-12208272
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Mark_Mark
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Man.. that’s so good to know you can shoot a .40 out of a 10mm glock. One of my 1st gun was a G23 gen3, I should have never sold it. I was thinking of eventually getting a G23, But now I know I can get a Compact Glock 10mm and put a .40 barrel in it! EXCITEDOnly if you are shooting new factory ammunition and reloads with brass that's been reloaded limited number of times. Brass case length gets shorter as reloaded repeatedly which is a well known fact.
As brass case length gets shorter, chambered rounds stop headspacing off case mouth and starts to headspace off extractor (To check, chamber reloaded rounds in barrel. If case base rim is below the barrel hood, the round will headspace off extractor). I don't think reloaders will stop reloading shorter length cases as most of them likely won't know when their brass case length gets short enough to start headspacing off extractor.
As I mentioned in Post #3, use of 10mm-to-40S&W conversion barrel will allow less gas leakage/more consistent chamber pressure build for better accuracy but I do not believe shooting 40S&W in 10mm will damage the firearm. Like shooting .38 Spl in .357 Mag ... No damage, but perhaps more cleaning. (And I shoot copper plated/washed 22LR in my .223 ARs with CMMG conversion bolt ... And no damage, just a bit more cleaning of fouling from blowback action)
I am actually doing a "myth busting" thread on longer vs shorter 9mm cases that no longer headspace off case mouth in the "Handloading & Reloading" subcategory and will post my findings in a new myth busting thread - https://www.thehighroad.org/index.p...ngth-and-accuracy.901574/page-2#post-12208272
WestKentucky
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The normal complaint is that the round headspaces with tail end support only coming from the extractor claw. People act like it will rip the extractor claw right off, but it’s not like the extractor claw doesn’t ride over the rim on every case anyways albeit at a lower speed. Truthfully I don’t see a reason to do it. Mechanically I don’t understand why it does work. A firing pin should not protrude that far into the chamber to reach out and whack a primer held forward by the extractor claw.
bangswitch
Member
You've got it backwards. Brass lengthens with repeated shooting and resizing. The die works the brass, pushing it back into correct dimension, which thins it in the area just forward of the case web. There's only one place for the brass to go, and that is forward. Case length should be measured after each firing when prepping it for reloading. As long as it is within SAAMI specs for length, load it and go. Once it exceeds SAAMI max case length, it must be trimmed back to within specs or it will not chamber and allow the bolt to close or the gun to lock up into battery. Eventually, the brass will get thin enough that it will split, and sometimes the case head will separate entirely.
You can shoot .40 S&W in a 10mm, just like you can shoot .380 Auto in a 9mm, but it is not recommended. The extractor holds the case in position by gripping the case head....most of the time. It is hard on the extractor and increases wear. The shorter cases are also prone to feed jams and if the extractor doesn't hold it, may fall too far into the chamber. In those cases it will not fire, and must be removed manually, as the extractor can't grab it so it can be ejected.
Shoot only the cartridge type that is stamped on the rear of the barrel that shows in the ejection port.
swg1
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Buddy and I as kids shot a bunch of 380 through a S&W 39. If the extractor holds it against the breech face, it shoots regardless of correct headspace.
It cycled too.
We didn’t notice until we picked the brass up for my buddy’s dad to reload. I’d suspect 40 in a 10mm would work the same.
It cycled too.
We didn’t notice until we picked the brass up for my buddy’s dad to reload. I’d suspect 40 in a 10mm would work the same.
1KPerDay
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RIFLE brass gets longer with firing/sizing. Semi auto handgun brass usually gets shorter with use. Try it.
I've done it I lot with Glock 20's and 29's with no issues at all. It has been 100% reliable, accuracy as well as point of impact has not changed. I can't say for sure how well it would work with another brand of pistol.
But until recently I've not had any reason to do it. Two years ago I had no problem finding 10mm ammo and it was priced exactly the same as 40 S&W, cheaper than 45. At that price point I didn't have any reason to buy 40 S&W. I had a few boxes of 40 S&W from when I used to have one and experimented with it.
But a friend of mine traded his 40 S&W pistol for a 9mm. He had several hundred rounds of 40 S&W that he tried to give me. We worked out a deal where I paid him a nominal amount for it.
But until recently I've not had any reason to do it. Two years ago I had no problem finding 10mm ammo and it was priced exactly the same as 40 S&W, cheaper than 45. At that price point I didn't have any reason to buy 40 S&W. I had a few boxes of 40 S&W from when I used to have one and experimented with it.
But a friend of mine traded his 40 S&W pistol for a 9mm. He had several hundred rounds of 40 S&W that he tried to give me. We worked out a deal where I paid him a nominal amount for it.
Buckeye63
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I owned Hipoint 10mm carbine for several years,
amazing carbine.. ran on low powered 10mm , heavy Underwood … also ate 40 S&W like a hungry dog …. 75% of the ammo that went through it was 40 S&W …. Never a hic-up
A guy at the range wanted it more than me .. and he had cash …
sparkyv
Member
I've shot 40S&W in my Ruger SR1911-10, XDM-10 and M610 with no problems and with 100% reliability. I have no heed to do it, but it's good to know that it will work in case I run out of 10mm ammo or if needed in a SHTF situation.
I too, have never seen or heard of a damaged extractor or anything else from this practice.
Accuracuy has not noticeably degraded when shooting 40S&W in my 10mms, but I shoot mainly offhand.
with no problems and with 100% reliability. I have no heed to do it, but it's good to know that it will work in case I run out of 10mm ammo or if needed in a SHTF situation.I too, have never seen or heard of a damaged extractor or anything else from this practice.
Accuracuy has not noticeably degraded when shooting 40S&W in my 10mms, but I shoot mainly offhand.
briansmithwins
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I wouldn't expect .40 in a 10mm to work well or not do damage eventually to the chamber or extractor, neither of which is going to harm the shooter.
I did have an occasion a couple months ago to find out what happens when shooting 9mmP out of a .40 HK USP*. The round fired and failed to load the next round. No damage was apparent to the pistol.
BSW
Had both 9mm and .40 USPs out while shooting with a friend. He picked up the 9mm mag and used it in the .40 pistol. I've since then taken to color coding pistols and mags with colored tape to prevent a recurrence.
I did have an occasion a couple months ago to find out what happens when shooting 9mmP out of a .40 HK USP*. The round fired and failed to load the next round. No damage was apparent to the pistol.
BSW
Had both 9mm and .40 USPs out while shooting with a friend. He picked up the 9mm mag and used it in the .40 pistol. I've since then taken to color coding pistols and mags with colored tape to prevent a recurrence.
Hesa Hard1
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A lot of people shoot .40 ammo thru their 10mm Glocks. I’m not one of them, preferring to use aftermarket .40 “drop-in” barrels in my G29 and G20. They work perfectly and don’t stress the extractor or anything else.
LiveLife
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While bottleneck rifle brass gets longer as it is repeatedly fired from case base wall stretching and thinning, this is not "Rifle Country" rather "Handguns: Autoloaders" talking about straight walled pistol brass, which will grow shorter and shorter as it is repeatedly fired and brass reworked with work hardening.
If you are not convinced of this well known fact, as member 1KPerDay posted, measure new/once fired brass case lengths and compare to brass that have been reloaded multiple times and you will find that most are shorter than SAAMI max length - https://saami.org/wp-content/upload...FP-and-R-Approved-2015-12-14-Posting-Copy.pdf
I am currently conducting another myth busting thread for 9mm longer vs shorter case length vs accuracy thread and while SAAMI max case length for 9mm is .754", very few will even come close and most will be around .750" and shorter.
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