After some hesitation, i started to increase the size of the transfer ports of my M60B in .35cal. This is my 1st airgun and therefore my knowledge is based on the uuuTube and reading up on what people discuss in here (mostly). So first of all, thanks for sharing experiences and knowledge, i really appreciate it.
My 1st question is:
Why the hell is there a bump in the ridge for the o-ring at the beginning of the barrel? that can't be right, since it must be the reason the original o-ring is broken at exactly that spot. luckily there was one spare o-ring in the bag of spares, that might fit. it has another color (green), and i wonder if that is because it is another material. if so. what might that be? original o-ring broken, first i thought it is due to the raw edges on the projectile probe,
but when i took it out, i saw a bump in the groove for the o-ring.
above is the shape of the groove , which caused the o-ring to get ground up by the projectile probe over time.
i will try the spare o-ring (black) instead, but only after i manage to remove the bumb (
unless anybody explains me that this on purpose and WHY?)
when poking at it, i realized it can move along the groove, so i thinK it is some kind of debris from manufacturing. but initially i was confused because it was aligned with the port hole at the bottom of the barrel.
below are some pictures of my process, in case you see coarse mistakes or have helpful and encuraging comments please let me know.
above you see the polished projectile probe. i left it at the original oval size, which is 5mm wide and 7mm long.
here's the valve taken mostly apart. the 4 transfer ports were each 4mm and are now 5mm.
here's the barrel port, before (5,5mm) and after (6.5mm). the barrel also had a laser etched serial number, which surprized me somehow.
and finally the barrel port with the probe port aligned. i'll polish this some more, for those who like it shiny. =)
