So I just had my first day of paintballing with my Mini, and it was awesome! The day didn't start great though; I couldn't chrono above 240fps, and adjusting the velocity via the back cap caused leaks from the back cap in some positions. I took out the bolt assembly and cleaned everything, and I also swapped out the V3 poppet for the V2 one I'd replaced as this was the only modification I'd made. I then only lubed the o-rings of the parts which were either moving or had something moving against them (i.e. the poppet, bolt, and boltguide tip), as there'd previously been lube on the large bolt-guide o-rings and the back cap o-ring. This solved the problem and it fired at 335fps, from which I adjusted down to within the field limit. So, could the poppet have had anything to do with the backcap leak, or was it more likely the lube I cleaned off of the static parts? I've since put the new poppet back in at home and screwed around with the back-cap with the marker aired up, and there were no leaks.
Also, although the day was awesome it wasn't without hiccups. It broke paint 5 times over a case and a half (half of this was Sterling Mace, half was Shield; only the Mace broke), so I intend to follow the guide to make the marker gentler on paint. A few things that I'd like spelled out though; what is blowback, and how will I know if my marker doesn't cycle?