HK USP Barrel Swap

Kevinfreem · January 17, 2018, 02:08 PM

Hey guys. One of my dream guns has been an HK USP in .45. Wife of the year bought me one for birthday and mentioned that the barrel could be swapped out for a .40 S&W barrel and the gun could switch to .40 easily. I was not aware of this but Im a bit leery of just ordering one. There is not a lot of information online about switching like that so I was wondering if anyone has done this before or has similar experience. Does it require different magazines as well? I wouldnt mind switching them out as I love shooting .40 as well but I dont know if i want to pull the trigger so to speak without knowing what might happen to the gun as a result.

Hammerhead · January 17, 2018, 02:28 PM

First I've heard of a .40 conversion for the .45 USP.
Do you have a link for this barrel?

Kevinfreem · January 17, 2018, 02:53 PM

No sir. In fact I haven't been able to find it online. That's what made me think the salesman may have been shooting his mouth off.

BarryLee · January 17, 2018, 03:11 PM

You might check this site for info.

http://www.hkpro.com/forum/forum.php

T. O'Heir · January 17, 2018, 03:18 PM

"...the gun could switch to .40 easily..." You'd need a new slide too. Rim diameter is 56 thou smaller on the .40. And 36 for the case body at the head. Plus different mags.
Far more likely that it'd be less fuss to buy a whole .40 &W.

lifesizepotato · January 17, 2018, 07:47 PM

USP 45 to 40 isn't really going to happen. They make 9mm kits (slide, barrel, spring and mag) that can be mounted on 45 frames, but they're only readily available in Europe. It's not an easy gun to do any caliber swaps on.

PSP · January 18, 2018, 12:15 AM

There were some HK models that could swap between .40 and .357Sig but I've never heard of .40 and .45 being interchangeable.

lifesizepotato · January 18, 2018, 01:11 AM

The three HK models that came in 357 SIG (USP Compact, P2000 and P2000SK) could all be changed to 40 with just a barrel swap, it's one of the features of that caliber since they're closely related.

45 to 40 though you run into issues with almost every part involved: mags, magwell, breechface, extractor, barrel (in many aspects beyond the bore diameter), springs, potentially simple geometry, it just goes on.

HistoryJunky · January 18, 2018, 01:51 AM

FWI I have seen used HK USP40 for around 400 dollars in my area.

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dgludwig · January 18, 2018, 08:09 AM

Can a USP 40 be converted to .357 SIG by simply switching the barrel? Will the magazines interchange?
As to the op's question, T. O'Heir is probably right: best to just invest in a pistol already chambered in .40 rather than trying to convert a USP 45 to handle the forty.

brian33x51 · January 18, 2018, 11:16 AM

Quote:

Originally Posted by HistoryJunky

FWI I have seen used HK USP40 for around 400 dollars in my area.

I got my police tradein usp 40 compact for about that this past spring. Love the reliability and SA trigger, don't like the first DA pull

TunnelRat · January 18, 2018, 11:48 AM

Try a different hammer spring. Wolff sells them or you can go the full match trigger route from hkparts or HK US directly (plenty of guides on the install).

lifesizepotato · January 18, 2018, 01:06 PM

Quote:

Originally Posted by dgludwig

Can a USP 40 be converted to .357 SIG by simply switching the barrel? Will the magazines interchange?

I don't think anyone makes a drop-in 357 SIG barrel, but otherwise it should work in theory. However, HK themselves tried to make a FS USP in that caliber and couldn't get it running to their (high) standards of reliability, so there may be something about the design of the full-size USP that doesn't work well with that round. (That said, I have a Compact in 357 SIG that is flawless.)

January 17, 2018, 02:08 PM	#1
Kevinfreem Member Join Date: January 10, 2017 Posts: 30	HK USP Barrel Swap Hey guys. One of my dream guns has been an HK USP in .45. Wife of the year bought me one for birthday and mentioned that the barrel could be swapped out for a .40 S&W barrel and the gun could switch to .40 easily. I was not aware of this but Im a bit leery of just ordering one. There is not a lot of information online about switching like that so I was wondering if anyone has done this before or has similar experience. Does it require different magazines as well? I wouldnt mind switching them out as I love shooting .40 as well but I dont know if i want to pull the trigger so to speak without knowing what might happen to the gun as a result.

January 17, 2018, 03:11 PM	#4
BarryLee Senior Member Join Date: July 29, 2010 Location: The ATL (OTP) Posts: 3,946	You might check this site for info. http://www.hkpro.com/forum/forum.php __________________ A major source of objection to a free economy is precisely that it ... gives people what they want instead of what a particular group thinks they ought to want. Underlying most arguments against the free market is a lack of belief in freedom itself. - Milton Friedman

January 17, 2018, 03:18 PM	#5
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...the gun could switch to .40 easily..." You'd need a new slide too. Rim diameter is 56 thou smaller on the .40. And 36 for the case body at the head. Plus different mags. Far more likely that it'd be less fuss to buy a whole .40 &W. __________________ Spelling and grammar count!

January 18, 2018, 08:09 AM	#10
dgludwig Senior Member Join Date: February 12, 2005 Location: North central Ohio Posts: 7,486	Can a USP 40 be converted to .357 SIG by simply switching the barrel? Will the magazines interchange? As to the op's question, T. O'Heir is probably right: best to just invest in a pistol already chambered in .40 rather than trying to convert a USP 45 to handle the forty. __________________ ONLY AN ARMED PEOPLE CAN BE TRULY FREE ; ONLY AN UNARMED PEOPLE CAN EVER BE ENSLAVED ...Aristotle NRA Benefactor Life Member

January 18, 2018, 11:48 AM	#12
TunnelRat Senior Member Join Date: May 22, 2011 Posts: 12,212	Try a different hammer spring. Wolff sells them or you can go the full match trigger route from hkparts or HK US directly (plenty of guides on the install). __________________ Know the status of your weapon Keep your muzzle oriented so that no one will be hurt if the firearm discharges Keep your finger off the trigger until you have an adequate sight picture Maintain situational awareness

January 17, 2018, 02:28 PM	#2
Hammerhead Senior Member Join Date: May 31, 2004 Location: Minnesota Posts: 2,432	First I've heard of a .40 conversion for the .45 USP. Do you have a link for this barrel?

January 17, 2018, 02:53 PM	#3
Kevinfreem Member Join Date: January 10, 2017 Posts: 30	No sir. In fact I haven't been able to find it online. That's what made me think the salesman may have been shooting his mouth off.

January 17, 2018, 07:47 PM	#6
lifesizepotato Senior Member Join Date: January 2, 2011 Posts: 210	USP 45 to 40 isn't really going to happen. They make 9mm kits (slide, barrel, spring and mag) that can be mounted on 45 frames, but they're only readily available in Europe. It's not an easy gun to do any caliber swaps on.

January 18, 2018, 12:15 AM	#7
PSP Senior Member Join Date: June 2, 2006 Location: Bowling Green Virginia Posts: 4,487	There were some HK models that could swap between .40 and .357Sig but I've never heard of .40 and .45 being interchangeable.

January 18, 2018, 01:11 AM	#8
lifesizepotato Senior Member Join Date: January 2, 2011 Posts: 210	The three HK models that came in 357 SIG (USP Compact, P2000 and P2000SK) could all be changed to 40 with just a barrel swap, it's one of the features of that caliber since they're closely related. 45 to 40 though you run into issues with almost every part involved: mags, magwell, breechface, extractor, barrel (in many aspects beyond the bore diameter), springs, potentially simple geometry, it just goes on.

January 18, 2018, 01:51 AM	#9
HistoryJunky Senior Member Join Date: April 7, 2010 Location: Freeport, IL Posts: 833	FWI I have seen used HK USP40 for around 400 dollars in my area. Sent from my SM-G930R4 using Tapatalk