[Micha]

Hi guys!

I am new to the forum and I have been searching for som answers on this topic but could not really find any.

I own a USP expert 9mm and it has fired about 6-7k rounds of standard 124gr rounds. So now I was thinking it might be time to replace the recoil-spring and the O-ring (the O-ring has been replaced 2 times before). By the way I had the green O-ring before. The ones i found now are black, is there any difference?

How often do you think these and other ware and tare parts need changing?

Also would you for any reason recommended a different setup beside the factory standard. I am thinking of buying the following parts from HK-parts;

USP 9mm, 40 Recoil Spring (HKUSPRECOILSPRING) https://www.hkparts.net/shop/pc/viewPrd.asp?idproduct=2067

HK 9mm Barrel O-Ring For Thread Protector - Black (9MMORING) https://www.hkparts.net/shop/pc/viewPrd.asp?idproduct=908

Snap Ring For USP Full Size & Mark 23 Recoil Assemblies (HKPMK23025) https://www.hkparts.net/shop/pc/viewPrd.asp?idproduct=1258

Hammer Spring For USP, P30, P30L, P2000 - Light (214300LT) https://www.hkparts.net/shop/pc/viewPrd.asp?idproduct=16489

I would be very grateful for your opinions on the matter:

All the best

 

[JonFrost]

Welcome to a great forum! The expert is my favorite pistol. Personally I would change the spring when you see ejection pattern change or whatever the manual says. I generally prefer factory but hk parts.net has great stuff. I'm sure you will get more precise answers from more knowledable members. Welcome again!!

 

[sean415]

I'm more of an if it aint broke dont fix it kind of guy.

If it's your carry gun or HD then send it into HK to get a thorough work up and cleaning if you wish and they will replace what they think is necessary.

I only use factory parts. Green and black o-ring are the same. Green I think is more of the old school look

 

[Micha]

Thanks guys!

I think i will just go for an other 500-1 000 rounds and then change the recoil spring and the O-ring. Leaving the hammer spring alone, for now anyway. I think that i will just stick to the original 12lbs recoil spring and not go for the wolf 10lbs spring that i see some people use. Black O-rings are easier to get by were I live so I will just go for them then.