hello..anybody out there..
I bought a used H&K USp 40 yesterday. It is a used gun but in excellent shape. i bought it from a gun shop and I don't know the round count in it. On all my other guns I know that the recoil spring has to be changed at 5000 rds. As for this H&K since I don't know the round count, i want to replace the recoil spring and start fresh. I looked at the recoil spring and (given my mechanical skills) it went over and above my head with this double spring package.
My question is divided into 2 parts:
a) how often the recoil spring must be changed
b) Where do i get a recoil spring and who would install it, would a gun smith be able to do that?
Thanks all H&K experts there.
Not an expert but a big fan of the HK line up. Currently own 3 P2000's. I had a USP 40 but never put enough rounds through it to need spring replacement. My guess without being able to look at one is that wolf, midway, HK direct, etc. would sell you the necessary springs unless the entire setup is completely captive in which case the whole assembly might need to be replaced. All I can recommend is take a good look at the assembly to determine if you want to tackle it solo and if not and you have a local smith talk with them about it. I think your 5000 rule is pretty reasonable by the way. One of these dual captivated setups certainly ought to do that or more. Sorry I'm not much help.
If the recoil spring is the one below the slide, why can't you go to your favorite gun shop and compare it to a new one? You could get really technical and rig up a non-invasive fixture to pull with a fish scale, or judge it by what you can feel, yours 1st, then the new, then yours again. Do it several times to make up for getting used to it (mine is always hardest on the 1st pull). You get muscle memory pretty quick racking it back a few times. Might ease your mind. Also, if you haven't, read the "torture test" in the "why HK" post.
Unless the recoil spring is broken you should get about 20k before you should think of replacing. I've never seen a broken one. The guide you need is the "HK field stripping guide for the USP". I got it online so you gogle search it. There are (2) springs on the assembly.... the recoil and buffer spring (do them both). If you are going to do this yourself get (2) of the retainer clips too. You'll bend the one getting it off, shoot one across the room and then get the last one to work. It is under compression when you disassemble so its not hard just tricky. Secret: Depress spring.... add needle nose vise grips.... remove clip....
All Parts of the USP line are build to take 20000 rounds of +P+ ammunition. If you use it as a service weapon or for defense go ahead and change the spring (it is not really an expensive part). If you use it just for the range and target practise, don´t change it and wait until it breaks. I remember our service USP we used in the German army. They were fired a lot on the ranges and the recoil springs never broke.