Proper bolt gap is ideally .25-.45mm, and can go to a maximum of .5mm. Yours is getting on the low end, but is ok for now. You've got about .002" of wear left until you're at the minimum. I'd get some new rollers.I just checked my MP5k bolt gap and it is .30 mm
Gun works perfectly so is this a good enough bolt gap or should I try to adjust?
Yep, that is correct, each step up raises the gap .1mm. The locking piece head can also wear, and is easily replaced. The last wear point is the trunnion, which is obviously not easily replaced. But in your case, all you need is the rollers because you're not even out of acceptable spec.So just to check I should put in a 8.02 rollers
Right now I have the standard unmarked rollers.
That would raise the bolt gap to .40 mm
Hold off on those rollers for now. If your gap is .025", you have other problems. Are you sure the bolt was fully closed? Did you drop the hammer on the empty chamber?Great info and THANKS from a newbie. I just checked my MP5 clone and maybe found out why my failure to cycle problems. My gap is about .025 " . Time to try some new rollers also.