Dan Mancini Posted December 17, 2021 Share Posted December 17, 2021 I was thinking of taking one of my .40S&W that I don’t shoot much and converting it to 10 mm. The gun is a ParaOrdnance TJ1640. Has anyone done this? Does it just involve cutting the chamber? Link to comment Share on other sites More sharing options...
Toolguy Posted December 17, 2021 Share Posted December 17, 2021 Yes, the chamber would have to be cut longer. You may also want to make sure that 10mm will fit in the magazine first. They probably will, but... Link to comment Share on other sites More sharing options...
Joe4d Posted December 18, 2021 Share Posted December 18, 2021 my 1640 ran well at 1.150 oal, not so well over 1.180,.... Link to comment Share on other sites More sharing options...
Paul B Posted December 25, 2021 Share Posted December 25, 2021 (edited) After you ream the chamber. The nominal SAAMI OAL of 10mm is 1.260. The old magic length for 38super was 1.255 and some reloads went out to 1.270 just based on the random resistance of the loading machine. These worked fine in para 38 super mags so the magazines for the .40 should work but may need some tuning for the right cartridge angle. For safeties sake would suggest doing this in a supported chamber barrel because the 10mm operates at a little higher pressure than the .40. Edited December 25, 2021 by Paul B Link to comment Share on other sites More sharing options...
Ronemus Posted December 26, 2021 Share Posted December 26, 2021 You'll need the strongest recoil spring you can find - 10 mm has a lot more energy and you'll batter the frame if you use the .40 version. Link to comment Share on other sites More sharing options...
shred Posted December 26, 2021 Share Posted December 26, 2021 Double stack 1911 mags can be a bit problematic with 10mm. They are long enough front-to-back, but the rounded corner at the front can drag on bullets. That's why very few STIs were made in 10. You can make it work, but be prepared to do some experimenting and mag tuning. Link to comment Share on other sites More sharing options...
Godzilla Posted December 30, 2021 Share Posted December 30, 2021 Paul B is correct, only in a supported (ramped) barrel. Here10mm_Automatic_SAAMI.pdf is the SAAMI spec for you. Link to comment Share on other sites More sharing options...
Joe4d Posted January 6, 2022 Share Posted January 6, 2022 ok didnt want to offer before I laid eyes on it, and forgot all about it till I was looking for my artic clothes... I just moved to Kansas from VA. Anyway right on top of a bin in a box I have an old Para ordnance factory P1640 barrel, It is pretty worn, probably 20 ish K rounds, as I used it for USPSA for 3 years, before installing an Edbrown and new bushing. Dont think I have the bushing with it. If it turns up before I find my bomber fur hat, I can include it. Make me a paypal offer to cover shipping its yours, this way you can experiement without messing up your stock configuration. would send in one of those small flat rate boxes, Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now