The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > The Smithy

Thread Tools Search this Thread
Old January 9, 2000, 08:24 PM   #1
Junior Member
Join Date: December 2, 1999
Location: Georgia
Posts: 9
Here's a question...
Could I take my full size USP .40, and get an aftermarket Jarvis or Bar-Sto 9mm extended length, threaded barrel and make (almost) a Tactical?

Do the USP 9mm Mags fit the .40 Mag well? ( I know where plenty of 9mm 10rd mags are right now for $26) Does the Mag release still work? Does the height of the 9mm mag put the round at the bottom of the chamber for the slide to peel it off and chamber it? Anybody tried?

I know the front of the pistol may not look as nice due to the smaller 9mm barrel not quite filling the gap. I have seen sites that will put the o-ring on the barrel as well, maybe that would tighten up the gap?

What about the chamber, will a .40 extractor pull out a 9mm round? Will the firing pin still hit the primer "on center"?

What's your opinion?

dmc235 is offline  
Old January 9, 2000, 11:49 PM   #2
George Stringer
Staff Alumnus
Join Date: October 12, 1998
Location: Earlington KY
Posts: 2,299
DMC, I don't fool with enough USPs to answer your questions. Sounds like a good project. Hopefully someone more knowledgeable than me on these guns will post an answer. George
George Stringer is offline  
Old January 12, 2000, 10:40 PM   #3
Junior member
Join Date: October 3, 1999
Posts: 910
I can only give empirical data, as I have not, nor will not try this particular substitution. Let's look at this from another angle for a moment. You are proposing to put a 10mm cartridge in a 9mm magazine. Does this sound like a good idea to you? Also, you are talking about buying a new barrel, custom made and then altering it with an o-ring to tighten the fit. That will cost some major money. Why not trade the full size in on a tactical and just add the extra money to the purchase?

Regarding the extractor. I feel confident that the larger .40 case (.380 - 9mm vs .423 - .40) will cause problems. The base of the forty is both larger and thicker than the nine is. If it works at all, it is sure to place undue stress on the extractor. You could probably get a .40 extractor that would fit your 9mm, if you can get HK to send you one (iffy proposition at best). And will the firing pin hit the primer 'on-center'? Probably not, but 'close enough' to cause the gun to go bang. But you are going to an awful lot of trouble to modify a firearm that doesn't need to be altered, as what you are trying to create, basically exists in a slightly large caliber. I would personally recommend against this. And if you do, the first time you fire it should be with a really long rope tied to the trigger, in case it blows up. This is not criticism, as I personally have modified a few pistols in my day for personal reasons and usage. In each instance, it turned out to be a lot of work that generally didn't accomplish the goal I was trying to reach. There's not enough time for us to repeat all the same mistakes. Trying to help. Jim
Wallew is offline  

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 11:30 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2017 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent:
Contact Us
Page generated in 0.08824 seconds with 7 queries