KSC USP .45 help.
 

Hey guys, I've had my USP for a while now and a couple months ago I purchased a Shooters Design slide and barrel. Quite impressed with it etc etc, but recently when retracting the slide, the small gold piece in the barrel that holds the spring keep slipping out and then the barrel gets stuck while the slide cycles back forward. This kept happening until one of my friends ended up losing the spring; does anyone know where I can get another spring, it's so tiny, as of now my gun is uses until I get this part.

Do you mean the recoil spring and the recoil spring guide?

No, he means a spring that presses against the inner barrel on the lower side of the outer barrel....if im correct, just find a pen spring and cut off two or so coils as a replacement.

Its really not worth buying anything.

Maybe? the piece is a very tiny gold colored cup that holds a very tiny spring, it sits in the bottom of the barrel and sits just in front of hop up adjusting thinger.

hmm, i shall look into this

yup, i lost that very peice on my usp compact.

Just go to the hardware store & find a spring similar in radius if a pen spring doesnt work for you.

if its falling out i would suspect that its not seated properly. the shooters design barrel has a a nasty habit of not being bored out all the way, causing your inner barrel / hopup to not be inserted all the way. verify this by looking at how the hopup sits in the chamber block, if its out or flush its probly not seated properly, it needs to be just inside the chamber block. also ensure that you c clip (barrel retainer) in installed properly, it could be backwards and lastly ensure that your barrel retaining pin is inserted (pin that holds the c-clip in place)
that little poppet valve (as i call it) shouldnt be able to unseat if everything is alligned and inserted properly. as for replaceing it a pen spring would work (from the cap piece you push down on to expose the pen tip) you should only need 4 or 5 coils, it dosnt need to be too strong or it will cause binding, too lose and youll have a misalignent which could result in tearing the hopup rubber (usp compact rubber will work fyi)

ensure that everything is aligned/ installed correctly, take the time to go back to square one and reinstall/ check everything, if you dont youll never solve the problem.

I used the stock piece that presses against the inner barrel and the stock spring.

They work better then what SD gives you.

alright guys I'm gonna see if I can get it to work, any recommendations on leaking mags? I had just bought a new mag and both of them leak, the first one after a lot of use, and the second right after one fill of coleman propane. I bought some glue and lubricant from a hardware store but havn't taken the mag apart yet.

i had one of my KSC USP45 mags leak, some times just removing the bottem plate and reseating it can solve the problem.
or you can add some silicon oil, or even some viscous greas(make sure it wont damage the Oring (well more like square ring).
also check the fill valve, i found that another USP mag belonging to another buddy had the fill valve on loosely, and a quick tightening of it solved his leak.

funny enough i had the egsact same thing happen to me with the mags lol. it took me quite a while to fix that. i tried soaking em in silicon, tried thread tape, it didnt work, i tried sealant glue and it didnt work... aaand i had to beat the shit outta my mag to get the bottom out of it again lol... id stay away from that. i just took it to the store and found some thinner similar sized orings. i put them on underneath the square one and pressed it in place. i had to have a buddy hold it down while i pressed the pin in place. that eventually solved it.