Hey guys, soooo... where to start? My dad recently started upgrading his VFC HK416 CQB with tons of upgrades, including but not limited to: SHS gears (reshimed and regreased) M110 Lonex a1+ BTC spectre v2 FET (soooo awesome) External stuff that I won't mention. Other non important things. All the above parts were installed well and performed great with only minor obstacles. It's when I got to installing this stuff that things got funky: Prommy 6.03 407mm barrel Prowin hop up (only one that fits the vfc 416) R hop and m nubs Multiple flat hopped buckings to try out Anyway, we had a reputable tech from our area install the r hop for us. When we first tested the gun we noticed quite a few quirky things: first of all, it was a bit over hopped. Secondly, it was veering a bit to the right, and finally, it was jamming for the first few shots. Another odd thing is that the issues seemed to go away as you would shoot, but completely reappear after taking a short break. So, obviously it needed to be opened up and looked at. Upon inspection I found the r hop itself to be installed very well, almost picture perfect. There were a few issues, a flab of the m nub had been torn off 99%, so I cut it off to remove the over hop (and did so successfully). Another problem was the bucking it was too tight for bbs to pass through easily and the torn m nub had been messing things up quite a bit. Unfortunately it was quite dark out when I next tested it with a different bucking, and the fixed m nub. Everything *seemed* fine until the next morning... Dun dun dun... Anyway, when I test fired it the next morning (today) it shot/shoots great on the first bb, then just love the rest out quite slowly as if some sort of jamming is going on. The sir nozzle cycles perfectly, going back and forwards without air leaks (I did the paper over feeding tube test). In really stumped on this one, the bucking (g&g green) is really soft and let's bbs pass through quite easily, and the r hop has been sanded at the front to prevent pinch type jams. Any help would be VERY appreciated, Thanks.