Zmarre Posted February 14, 2011 Report Share Posted February 14, 2011 I recently bought some Prowin 20rnd mags for my Viper XM177. Two out of six work flawless, the four others don't. Problem is that the bolt only moves backwards for about 5mm while shooting, thus not beeing able to cock the hammer. If I rack the bolt manually, I can again shoot one bb but have to cock manually again. Anyone has any clue what's causing this? All these mags look 100% identical to me, but some work while others don't. Link to post Share on other sites
BaBaBooey Posted February 14, 2011 Report Share Posted February 14, 2011 My initial guess is that there is damage to the magazine packing which is preventing gas to properly flow into the nozzle (it's possible that the Pro-Win's are not designed for it where the magazine is sitting too low...I don't think that's the case as you mentioned some are working fine. I suggest using a chrono to make sure). I would swap the packing with one on the working magazine to see if that corrects the problem. Link to post Share on other sites
Zmarre Posted February 14, 2011 Author Report Share Posted February 14, 2011 I already bought the 0-rubbers, didn't make any difference... Link to post Share on other sites
BaBaBooey Posted February 14, 2011 Report Share Posted February 14, 2011 Just to be clear, you replaced the gas route packing? Link to post Share on other sites
Zmarre Posted February 14, 2011 Author Report Share Posted February 14, 2011 Yup. But it didn't make any difference. And I just chronoed my gun to see if there's any difference in the mags power: all mags, working at semi auto or "bolt action", chrono 300FPS. I really don't understand. Link to post Share on other sites
sigma3 Posted February 14, 2011 Report Share Posted February 14, 2011 I had the same problem with my WOC. I never got 100% to the bottom of it, but my conclusion was that it's likely caused by the much stiffer valve on the Pro-Wins compared to the other mags I had (G&P, JG) and the hammer spring not being set up for that. Link to post Share on other sites
Enforcer Posted May 20, 2011 Report Share Posted May 20, 2011 I'm reviving this thread because i experience similar problems with my Ino M16A4 2010 and 20rounds ProWin Mag. Was the problem fixed with switching to a stronger hammer spring? I though the valves were all the same if they are from the same company... btw... i didn't have a replacement rubber so i filed it down until it didn't stick anymore ( about 1mm ). So my guess is really a weak hammer spring. Trying to get hold on a G&P 120% hammer spring, i doubt the RA 100% hammer spring will help or maybe the realsteel hammer spring will fit? The 30 rounder worked flawlessly to my surprise even with the original rubber, no sticking or rubbing against it, giving my rifle a nice kick ( with 9mm buffer ). I tried it when realising the bolt via bolt catch while holding the bolt and moving it forward manually. It didn't get stuck as mentioned by others so hopefully i don't have to replace it. Link to post Share on other sites
Recommended Posts
Archived
This topic is now archived and is closed to further replies.