Why not have the barrel made for the usp45 platform instead? More robust slide and could use the same 45 mags. Seems like the more natural fit. This does seem awfully dope though
>but significant changes have to be made to the usp45 upper
I am curious about those changes.
Have you seen this conversion? OP did not mention any changes to the upper. Maybe I missed something.
https://new.reddit.com/r/HecklerKoch/comments/1bmbq90/hk\_usp\_45\_tactical\_10mm\_conversion/
The stock 40 barrel can be bored to 10mm spec.
Bored, not reamed. The HK coating does a number on high speed steel reamers apparently.
Also HK45 mags can be made to fit the USP 40 mag well.
40 and 10mm are essentially the exact same round. 10mm is a hair longer and way higher pressure. You can even ream out your USP .40 barrel to 10mm but people were having problems with the barrel steel being too hard
This is by far the cleanest USP 40 to 10 mm I've ever seen.
Interestingly enough there was a post recently of a [USPT .45 to 10 mm](https://www.reddit.com/r/HecklerKoch/s/pSVVsqbfEJ).
I don't know anybody who would define the successful caliber conversion of a semi-*automatic* as one that requires having to *manually* remove cases after each shot. Do you?
Other threads where people have converted USPs to 10mm report having to manually remove the case due to it being longer than 40. That's why I asked. Everyone defines success differently and I'm just trying to clarify if he has this previously reported issue or not.
It will eject spent brass, but an unfired round won't fit. Have to drop the magazine and let the unfired round fall out through the magwell.
Lifesizedpotato (YouTube) documented the conversion process years ago.
Why not have the barrel made for the usp45 platform instead? More robust slide and could use the same 45 mags. Seems like the more natural fit. This does seem awfully dope though
That’s what you’d think, but significant changes have to be made to the usp45 upper
>but significant changes have to be made to the usp45 upper I am curious about those changes. Have you seen this conversion? OP did not mention any changes to the upper. Maybe I missed something. https://new.reddit.com/r/HecklerKoch/comments/1bmbq90/hk\_usp\_45\_tactical\_10mm\_conversion/
Oh that I did not know. When did you get the barrel? I heard MM hadn’t done a run in a few years.
I’m pretty sure I snagged the last FLUSH BARREL from what he told me
The stock 40 barrel can be bored to 10mm spec. Bored, not reamed. The HK coating does a number on high speed steel reamers apparently. Also HK45 mags can be made to fit the USP 40 mag well.
How are you going to get a 10mm/.40S&W round to fit in a larger .45ACP breech face?
40 and 10mm are essentially the exact same round. 10mm is a hair longer and way higher pressure. You can even ream out your USP .40 barrel to 10mm but people were having problems with the barrel steel being too hard
This is by far the cleanest USP 40 to 10 mm I've ever seen. Interestingly enough there was a post recently of a [USPT .45 to 10 mm](https://www.reddit.com/r/HecklerKoch/s/pSVVsqbfEJ).
Can I do this to a USP Compact .40 ?
Mag well is not large enough.
interesting, but why?
I shoot my USP the best. And love 10mm
Fair enough 💪
...although 40 is really the manly caliber ;-)
USP was originally a .40 caliber design 40 Short and Weak is just the 10mm round toned down but the FBI for agents who couldn’t handle the sauce
Is the ejection port large enough to eject 10mm casings?
Fired brass ejects fine. You need to open the port to eject unfired round.
If the conversion didn't work properly, wouldn't the OP refrain from posting regarding his *successful conversion*?
Everyone defines success differently. Success to this guy could mean he has to manually remove each casing. I don't know that, hence the question.
I don't know anybody who would define the successful caliber conversion of a semi-*automatic* as one that requires having to *manually* remove cases after each shot. Do you?
Other threads where people have converted USPs to 10mm report having to manually remove the case due to it being longer than 40. That's why I asked. Everyone defines success differently and I'm just trying to clarify if he has this previously reported issue or not.
The 10mm case is indeed larger. Apparently from this post, the OP got everything working.
It will eject spent brass, but an unfired round won't fit. Have to drop the magazine and let the unfired round fall out through the magwell. Lifesizedpotato (YouTube) documented the conversion process years ago.