Alrighty im over 1K rounds in my USP .45 so i started to do a detail strip. Stripping the frame whent. But i was looking at the slide to swab out the firing pin chamber and noted the pins. They look like one time use roll pins so i didnt drive them out. So now my question, what size of roll pins will i need(both firing pin and extractor) to put the slide back together?

Quoted: Alrighty im over 1K rounds in my USP .45 so i started to do a detail strip.

Why???????    

+1 to Bobcole...

Don't detail strip it.

Maybe once you hit 25-30k rounds...but 1k?  Don't do it.

Meh well im used to 1911s and also i was bored, and me being of a mechanical mind i started to take stuff apart. I do that alot realy.

Quoted: Meh well im used to 1911s and also i was bored, and me being of a mechanical mind i started to take stuff apart. I do that alot realy.

With the HK, you must resist the temptation.

Detail stripping a USP every 1k rounds will do more harm than good.

Well i guess ill wait untill i hit 5billion rounds then. I took apart the frame wich is where the mysterious parts are so i guess you could say my curiosity is satisfied.

Has anybody stripped their slide??? Just curious.

I've detail stripped my AF fullsize 9mm twice to clean including firing pin and extractor, one semi detail for the LEM. Haven't changed any of the pins. Has been about 2k since the last strip and none of them have shifted. Though the next time I'm going to measure and replace them just to be safe.

Your mileage may vary, though I like to keep a clean house. If you're even somewhat mechanically inclined, have some small tweezers a small precision screwdriver it really isn't all that hard. Just be mindful of springs/detents under compression, don't damage the flat spring, and be patient putting it back together since getting everything lined up on the sear axle and positioning the trigger return spring can be tricky *especially* your first time.