LP10e bolt "dent"

[cnnhead]

My LP10e has started recently showing some resistance while opening and closing the bolt. I removed it and noticed a kind of "dent/imprint" with a small bulge at its end (see the picture). Any idea why that may have happened?
Beside that, everything works ok, the velocity is stable (ca. 157m/s), absorber is active and goes about half way back.The mileage is ca. 10k pellets.

[rmca]

That part is what catches the hammer and cocks it (red circles)

1.JPG (49.95 KiB) Viewed 2399 times

I would suspect that you have adjusted too much the hammer spring (right arrow), or you have a weak valve spring (left arrow).
If the bolt is difficult to cock, you may be bottoming out in the hammer adjust screw/spring.
Try to unscrew it one turn and see if you can cock the gun easier. If so, you need a new hammer spring.

Hope this helps
rmca

[brent375hh]

I don't know how you cock it, but I was just watching many people shoot last weekend that grabbed their lever and yanked it back, more focused on the next shot, just like some people close car doors with way more force than required.
Perhaps if you just remove the burr, and cock easily until you feel the sear click into place the problem won't reappear?
As RMCA suggested, if it takes a lot of effort, you may have your striker spring stacking. Replacing both springs might help, but 10K rounds isn't very many.
The other indicator of vigorous cocking is flattening of the rear sight screw threads, as that is the rearward bolt stop.

[cnnhead]

Thanks a lot for your insight. The direct problem was obvious - the burr that was formed on the bolt. I filed it down and everything goes smoothly now.

I don’t think that it was caused by a vigorous opening the bolt. The reason was rather hitting the bolt by a striker (part #19) which may have happened while dry firing with the bolt almost entirely open. Quite a probable situation especially with a safety flag inserted. I will have an eye on this.

Thanks again for your help.

[brent375hh]

That would certainly make sense. Under normal dry fire condition the striker is arrested by the cam with the bolt in the T position. If the bolt is open more, the striker is then hitting the bolt itself.
I have accidentally done this a few times myself without a flag. It certainly made a different sound and the cocking lever jumped down to the T position.