.40/10mm upper question

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[ARCHIVED THREAD] - .40/10mm upper question

Posted: 11/4/2003 7:24:09 AM EDT

Hey guys question about .40/10mm. I have a oly 40 upper for the AR. Now best I can tell the olympic arms mags for a .40 and 10mm upper are the same mags(got to confirm that though) If thats the case, and I want to go 10mm can I just have the barrel rechambered to 10mm? If I do that can I still shoot .40 out of it if I wanted to? just thinking about it so I thought I'd ask. Ok I forgot this part. The upper will be chopped down eventually as part of an SBR project when/if(depending on a new AWB) I pick up a pre-ban lower.

Thanks

Posted: 11/4/2003 11:43:10 AM EDT

[#1]

I don't think you can shoot .40 & 10mm out of the same chamber because the cartridge headspaces on the case mouth. If it's chambered for 10mm the .40s would be to far forward. (Unless the extractor held onto it tight enough--I've seen a 9mm fired in a .40 that way, but it wasn't pretty.)

Posted: 11/5/2003 4:47:04 AM EDT

[#2]

Thanks for the info Mike. I wasn't sure if they were like .38/.357 and the such or not. I should be able to get the 40cal barrel re chambered to 10mm without a problem though right?

Posted: 11/5/2003 5:18:58 AM EDT

[#3]

The 40 and 10mm are a lot like the .38/.357 [red]EXCEPT[/red] the .38/.357 cases have a rim on the back to headspace from.

Posted: 11/5/2003 5:31:38 AM EDT

[#4]

I would contact Olympic about it since they make the uppers.
One problem may be the feeding since the 10 is longer.

Posted: 11/5/2003 5:31:39 AM EDT

[#5]

Assuming that the magazines and such are the same so the 10mm will feed OK I would think you could just rechamber. You might have to change the recoil spring too.

Posted: 11/5/2003 11:51:17 AM EDT

[#6]

Thanks guys. .

Posted: 11/5/2003 2:55:39 PM EDT

[#7]

Assuming that you are using .41AE UZI mags right now, Oly will have to modify the mag a bit to allow them to feed 10mm.

Posted: 11/6/2003 4:52:42 AM EDT

[#8]

There the modified 41AE Uzi mags correct. They have already been modified to feed the 40 so they should not need to be modifed anymore.

Posted: 11/6/2003 6:47:50 AM EDT

[#9]

Quoted:
There the modified 41AE Uzi mags correct. They have already been modified to feed the 40 so they should not need to be modifed anymore.

View Quote

Actually, I think Olympic modifies the 10mm mags to accomodate the longer cartridge length. They pinch the mags a little bit to create a little more room for the bullet nose in a full-length 10mm round. You could always load your rounds to a little shorter OAL and see if they fit.

Posted: 11/6/2003 8:48:28 AM EDT

[#10]

Quoted:

Quoted:
There the modified 41AE Uzi mags correct. They have already been modified to feed the 40 so they should not need to be modifed anymore.

View Quote

Actually, I think Olympic modifies the 10mm mags to accomodate the longer cartridge length. They pinch the mags a little bit to create a little more room for the bullet nose in a full-length 10mm round. You could always load your rounds to a little shorter OAL and see if they fit.

View Quote

I got to stop at the gun shop later today, maybe i'll take the mag with and check while I'm there.

Posted: 11/6/2003 3:25:26 PM EDT

[#11]

Quoted:
There the modified 41AE Uzi mags correct. They have already been modified to feed the 40 so they should not need to be modifed anymore.

View Quote

KC3 is correct. Oly will need to pinch your mags to fit the longer 10mm round.

You can find out more about a 10mm Oly AR here:

[url=http://www.bren-ten.com/main-site/id17.html]Very Cool 10mm Oly Setup[/url]

[ARCHIVED THREAD] - .40/10mm upper question

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