Jarvis Gunsmithing's Replacement Barrels

Well guys, I just heard about this one. I'll have more information for you as it comes in (Jarvis has promised me a full packet of info on their products.) For now, here is what I know. Jarvis has the following barrels available for the USP Full Size: 9mm, .40 Smith & Wesson, and .45 ACP. These are available in either standard 4" length, or 5.5" extended. Threading is optional. Also available is a drop-in replacement barrel for the USP40 chambered for the .357 SIG cartridge. This also is available in standard and extended lengths, with threading and porting available. Those of you waiting for BarSto to release that .400 CorBon barrel for your USP45s need wait no longer. Jarvis has it, again in both lengths with threading/porting as extras.

I don't have the metallurgy specs on the barrels available, but they are certified 4150 steel and have fully supported chambers. Most applications should not require gunsmithing as the USP is developed with very tight manufacturing tolerances.

I just received my 5" .357SIG drop-in replacement barrel for my USP40. I had it threaded (9/16x32x3/8") as well for the possibility of future accessories. The barrel arrived in perfect condition with no tooling marks on it whatsoever. Corners were crisp and everything looked meticulously machined. It came in a black finish with the top of the breech block polished. The only thing I would have hoped for is polishing the feed ramp.

At the range, the .357SIG is an attention getter. It's got an impressive roar that brought everyone over to see what I was shooting. Recoil is very controllable in the USP. Instead of feeling like it was heavier recoil, it seemed comparable to the .40 caliber, only that it lasts longer. I had no trouble getting 1" and 1.5" groups at 25 feet.

There is one caveat. Due to the nature of the necked down cases, it is difficult to correctly seat the cartridges in the magazine when loading. This can cause the USP to jam (yes, jam, believe it or not!) because the cartridges want to nose down due to improper seating. It can also make it quite difficult to load the magazine to capacity. Though I was discouraged, a friend of mine quickly found the solution to the problem. By sharply rapping the bottom of the magazine against a table, the floor, or even your hand, the cartridges realign themselves into the correct position within the magazine. You may want to put your thumb on exposed cartridge to keep it from flying out of the mag while you do this. Repeated tests by racking the slide by hand and live fire show that this appears to solve any feeding problems.

Overall, I'm very happy with this barrel. It is incredibly fun to shoot and very accurate. I'm tempted to order a replacement .40S&W barrel (also extended and threaded) as Jarvis claims these barrels can shoot 1.70" groups at 50 yards!

Gregory McGraw (stray@catt.com) ordered a .400 CorBon barrel for his USP45 from Jarvis. Here is what he had to say about it:

Here is my personal review of the Jarvis .400 drop in pipe:

After seeing the review of the .357SIG barrel on the Unofficial USP Homepage, I decided to give Jarvis a call and order a .400 CorBon drop-in replacement barrel for my USP .45. I was both pleased and a bit curious about the price being as low as it was ($195.00 for an extended 5.5" barrel). I called Jarvis Gunsmithing when I arrived home from work and caught Mr. Jarvis himself just as he was walking out the door. He put down his things and took my order (and stayed late and packed it for shipping early the next morning.). Needless to say, I was very impressed by the personal touch he treated me with.

UPS took their own sweet time in delivering it to me (8 days) and I was getting worried they might have lost it.

The barrel finally arrived in it's wrapper and I eagerly tore into it like a child on Christmas morning. The non-reflective black finish matched the coating of the USP beautifully. It had no rough edges and was a really professional job. Instead of the "Jarvis .400 Cor-Bon" on the slide, I almost expected to see the HK logo. (It was that well-made.)

Installing was a simple drop-in replacement and I was ready to shoot. The extended barrel really gives the .USP an intimidating look. (My wife thought I had bought another gun!) I ordered mine plain, but Magna-porting and threading (al la SOCOM) is optional.

I went down to my local ammo dump (The Georgia Gun Trader in Ringgold, GA) and bought all the .400 Cor-Bon ammo he had. (He has other .400 customers, so I was only able to find the 165gr. 1300FPS JHPs.) The ammo was priced at $15.50 for a box of 20 if anyone is curious.

I first loaded a standard 10-round clip and cycled the slide through to make sure it would feed properly. I discovered that the magazine I was using had a weak spring (Doh!) and loaded another. This one passed the manual slide-cycle test. On the 4th shot, I had another failure to feed. This annoyed me and removed the slide and examined the barrel. I noticed that the feed ramp was not polished like the original barrel. I left the range and went home to my Dremel tool. After polishing the feed ramp to mirror-like perfection, I went back to the range. Performance was flawless from here on out.

Now let me preface this account by saying that I do not claim to be an expert marksman. There are plenty of shooters out there that are better than I am, and I freely admit that. Standing in a Weaver stance, I slow-fired 10 rounds at a 15yd target. All 10 formed one nice big hole about an inch above the bullseye. (My bad. The aiming point is slightly different than .45ACP) I got consistent 1.00" to 1.25" groups at 15 yards. Moving on to 25 yards, I spread a bit more getting 2.00" and under groups. (averaging about 1.50" to 1.75" from a supported position) For a caliber I wasn't that familiar with, I was impressed. This barrel was as accurate if not more than the original polygonal bore HK barrel. (again, this might vary from shooter to shooter)

I noticed that the extended pipe added another benefit aside from sex appeal and slightly higher velocity: it added some weight at the front that helped compensate the recoil. I would have to say that it had less FELT recoil than my .40S&W Glock 23. Again, I was impressed.

To sum my feelings up, all I can say is that Jarvis Gunsmithing did one hell of a job. Had I known the feed ramp would not be polished, I would have asked that Jarvis do it before they shipped it. (The pamphlet that shipped with the barrel advertises this service for $25.00, along with many other gunsmithing services) I would definitely do business with them again, and intend to in the future.

Here are the prices:

For more information, you can contact the manufacturer directly at:

Be sure to tell them you heard about it on the UHK USP Home Page!

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