Help! 10mm gun with .40 cal barrel

[rdt]

my first gun, bought a couple years ago, a Tanfoglio Witness P, (im told this is a CZ clone?) with a composite frame. Bought a second mag for a .40 witness but it never fit right, engaged the mag release but could slip out. Closer inspection the new mag is slightly shorter (front to back) than the mag that came with the gun - and .40 rounds slip back and forth about 3/16 inch in the original mag. No play in the new mag. The barrel is marked .40 S&W. I recently learned .40 and 10mm differ only in length of the cartridge.

so whats the deal? Is this really a 10mm gun i have been firing .40 through? Or is it just a b**tard? Can i fire 10mm through a .40 barrel? Or do i just have a bunch of mismatched gun parts to get rid of?

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[Boats]

If you bought it a couple of years ago, hadn't you fired it by now? If so, what did you fire from it?

 

[PhysicsGuy]

The cartridge stamped on the barrel is the cartridge that it is chambered in, so it appears that you have a .40. The newer witnesses only have one sized frame, so any magazine will fit in the frame. It just sounds like you had a 10mm magazine, which is not a big deal to use with .40 S&W. However is it NEVER safe to fire a dimensionally different cartridge when it is head spaced on the mouth (like all autoloader cartridges are), so you should never shoot .40 S&W in a 10mm pistol (however it is safe to fire in a 10mm revolver with moon clips because it headspaces on the rim that way)

 

[rdt]

fired maybe 400 rounds of .40 S&W, two thirds factory reloads. seemed find except lots of failure to feed correctly/completely. all those unfired rounds spinning away as i racked again, well i chalked those up to being a novice: failure to keep tight control on the muzzle, ive heard .40 is considered a snappy round, composite body leaves it top heavy so it tends to spin - all robbing the recoil from the slide.

local pistolsmith is who suggested the original mag is for 10mm.

so options are...

replace barrel/slide/etc with 10mm

knuckle down and buy 10mm mags for a .40 S&W

try to sell it as is

part it out?

 

[rdt]

headspaced? mouth?

do you mean the breech (?) wont be fully closed?

 

[PhysicsGuy]

headspaced? mouth?

do you mean the breech (?) wont be fully closed?

Headspace is the distance between the front and back of the cartridge, and is how the cartridge contacts the barrel when inserted. An autoloading (rimless) pistol cartridge usually is stopped on the mouth of the case when it is inserted in the barrel, and a rimmed cartridge, such as one for a revolver is held at the rim. When attempting to use a .40 S&W in something like a 10mm, the round will appear to chamber fine, but the case is not correctly supported or headspaced in this fashion, and is extremely unsafe. If it was the other way around, and a 10mm was inserted into a .40 S&W chamber, the round would headspace too shallow, and the gun would appear to be out of battery.

Here is a wikipedia explanation;

http://en.wikipedia.org/wiki/Headspace_(firearms)

 

[rdt]

thanks for the explanation and the link!

 

[rdt]

does anyone think its worth the trouble to change the barrel to a 10mm? or just buy 10mm mags, which seem harder to find, cause the .40 cal mags do not work.

 

[d1esel]

Tanfoglio use to import large and small frames. They stopped importing the small frames many years ago. It sounds like you have a magazine for a small frame gun. Large frame mags measure 1.345" x 0.850". Small frame mags are 1.250" x 0.800".

 

[Lange22250]

You need to understand that Tanfoglio makes 2 different frame sizes. you have a large frame, so you need large frame .40 mags, which are probably identical to 10mm mags.
The reason they do that is to increase magazine capacity. Tanfoglio makes a lot of pistols used in IPSC in Europe, where they are more popular than 1911's.
Leave the pistol alone and get more large frame mags as long as you have no function issues with the mag that came with the gun. If you want a 10mm as well, you can get a 10mm barrel and it should be good to go.
I use a large frame witness in 9mm and it's now my favorite.
This guy did all the work on my pistol and he's a wealth of info and parts, as well as being a good guy and very helpful.
http://www.henningshootsguns.com/index.html

 

[rdt]

awesome. hennings site is cool. anyone out there want to buy a small frame witness mag?

 

[supergenius]

double post

 

[supergenius]

awesome. hennings site is cool. anyone out there want to buy a small frame witness mag?

.40?


Is this for a STEEL FRAME pistol? They are different for the poly.

Post a couple pics please including one of the follower if you would. I have a .40 Baby Eagle (another CZ "clone" ) and just bought a 12 rounder... Id be interested in seeing it.... How many rounds of 40 does it hold?? Hopefully 12, and hopefully for a steel frame. Mine is a compact 40 with the 3.5" barrel.
LMK.

THX

 

[supergenius]

iM INTERESTED

 

[greydog111]

Dude! Have ya priced 10mm lately? Let alone try to find some! $35.00 for range pills. Yikes! Greydog.

 

[rdt]

lets move this discussion about the magazine to the classifieds where it belongs, shall we?

 

[supergenius]

You asked if anyone wanted to buy it... I do. How bout we take it to PM. LMK if its for a steel frame BE (may be marked AE41 at the bottom of the mag?) . If so (and it holds 12 plus), ill take it off your hands, would like to see a pic.

Thank you.

 

[rdt]

yes, 12rds. i assume its for steel frame, the part number says "witness," not "witness p." MG-GT40-12, no other markings. Mec-Gar btw. working on pics. . . gotta run to work tho.

 

[supergenius]

yes, 12rds. i assume its for steel frame, the part number says "witness," not "witness p." MG-GT40-12, no other markings. Mec-Gar btw. working on pics. . . gotta run to work tho.

Ill take it, just LMK man.

THX