g&g viper pneumatic blowback stopped working

[hasbromad]

Hi wonder if anyone can help I took my m4 viper apart yesterday only took upper receive off of lower receiver to clean and grease. When I put back together and fired the gun the pneumatic blow back didn't work but gun still fires bbs fine just blowback doesn't work.Any ideas guys what could be causing this to not work? the little flap on the side where u access the hop up all so does not flip open but did before I took apart many thanks

[jonny lovegrove]

Re: g&g viper pneumatic blowback stopped working

youve probably bent it ever so slightly (there is next to 0 gap in there) pop it open again and have a look. what were you greasing btw? as it may well be too thick grease for the pneumatics.