[N_Force]

first, most of the gas airsoft rifle need to be lubed before use as always, even some manufacturer lubed ones was just not apply into a right contacted location.

second, for shells eject ones, break in is always a must, if you know about it, the extractor is the first one, as the edges are so sharp and cut the end of shell then causing uneven all around and get jam. so slightly file the corners and edges on the extractor that contact the shell end, would minimize the shell end damaged.

third, the pathing for shell loading forward to the chamber should be smooth, based on the first video showed the aide of shells got scratches, were causing from it. simply lightly file or sand that pathing area smooth and allow shells passing easily would be better.

forth, if shell could jam into chamber after loaded, that could be the shell over size a bit. remember which one got jammed and compare the length even dimensions see if the size out of spec. or check with the chamber see if the chamber inside smooth or not? sometimes the inside may have some bumpy metal and causing jam or not smooth loading.

final, the worn on metal parts are all normal for all metal contacts. if the wears were to deep than you should think about to sand it smooth to minimize sticky movements. also apply thicker grease would be good for bolt action rifle tho, apply on those wear area would help.
if you have got struck and or not smooth movement during loading shell, you should not force to do it, thats how to make the wear worse, try to find out where is it coming from and fix it.

hope all these could help what you need. happy reading