Is it possible that the BB stopper in hopup chamber is too tight and holding on the nozzle?The head threads into the cylinder, you need to make sure you tighten it down. But something isn’t right, if the nozzle is getting stuck in the chamber. Perhaps the nozzle is too big or something got rammer jammed with the bb stoppers. I’m not too familiar with that clone and compatibility.
I have a similar issue with the AA HU in an SSG10. The cylinder requires quite some force to push into the HU along the last 2mm. As it’s only about the last 2mm, that’s way past the bullet holders, it must be sth else in my case. Also, I can see dents/scratch marks on the cylinder head, limited to the very top of the head, by which I mean, if you look right into the nozzle like looking into the barrel, I see marks on the 12 o’clock position. But only on the part between the nozzle and the base of the cylinder head. The nozzle itself seems to glide smoothly. My guess is the cylinder head and HU are slightly misaligned. Grinding and smoothing this mentioned part of the cylinder head with a steel polishing paste seems to yield slight improvements without corrupting nozzle air seal. So maybe you should watch out too for any visible marks on the cylinder head where it might have come into forceful contact with the HU.Me neither I didn't even touch it, I just installed it like it was.
I will also try some teflon tape maybe it will help to keep it more secure
Great info, thx! Makes a lot of sense indeed. I just noticed after you mentioned it and checked, that there basically seems to be no air seal at all, while it is flawless with the SSGs stock HU. I also changed the bucking from an autobot 60 to a ML delta 80. I thought it makes a lot of sense with a 5J spring and heavy bbs. But now i guess I have to figure out where exactly it’s leaking. It likely to be where the cylinder gets stuck right? So if it has to much friction in one spot it might have a leak on the opposite side. Probably I’ll need a guide sleeve, as there’s only a glide ring where the cylinder leaves the receiver. It also never occurred to me it could go too far in?! I mean how loose is this vsr standard after all 😅? You buy cnc machined parts and get sth not fitting that much? Kinda hard to comprehend rly.Without a cylinder guide sleeve, it’s very easy to push the bolt forward with the nozzle entering the chamber at a slight angle. It’s because you are left or right handed so naturally you are pulling or pushing in one direction more than the other. This can cause wear on the nozzle. But if it’s NOT that, and the bb stoppers are NOT too tight, I’ve had a certain nozzles fit tight into a certain bucking. Nozzle placement is one of the most important adjustments to improve accuracy. In my opinion, after messing with it. One way to do this is add a damper pad that’s 1-1.5mm thick on the back of the hop chamber, where the cylinder head hits. However, it will only benefit you if your nozzle placement was too far in. You’ll only know if you see an improvement. If you add the damper and there’s no change, AND you still have a good air seal, you’re still in good shape because your nozzle won’t go in mega far into the bucking, and possibly fix your “last 2mm it’s tight” issue.
…Hope any of that made sense
I think the Autobot buckings are better, but that’s my preference. But I feel like something isn’t installed correctly. There should be SOME seal but I can see the seal being shitty with such high joules. However, if the high output was the issue, it would not be sealing internally, and the air seal at the cylinder head would be trash. Something is probably off in terms of chamber placement or bucking install.
Thx for elaborating! Found the issue. The high force needed to insert the cylinder head into the bucking actually is the tightness of the bucking. If you take the cylinder out of the gun, the HU with attached barrel will easily defy gravity just with the bucking clinging to the nozzle. So not much to do there, it’s just the way it is. Also, that end is super airtight. What was leaking though was the frontal end of the bucking sitting on the barrel. I applied two layers of PTFE tape over that end before reattaching the barrel spacer and barrel back into the HU, now super tight as well and the whole thing maintains the airseal like a charm 🙂 During the whole process the nub got lost though 🙄 I guess I can just rebuild one from a segment of a nail?I think the Autobot buckings are better, but that’s my preference. But I feel like something isn’t installed correctly. There should be SOME seal but I can see the seal being shitty with such high joules. However, if the high output was the issue, it would not be sealing internally, and the air seal at the cylinder head would be trash. Something is probably off in terms of chamber placement or bucking install.
 they are parts machine to fit and operate. Tolerances are different across the board with different receivers, barrels, etc. if they machine it to fit tight it would be too tight depending on your setup. Also with an airsoft sniper rifle you don’t want 2 metal parts being tight af. The guide sleeve is a softer material like delrin, polycarbonate, etc. something metal can slide in.