Hey i had a problem with bad blowback earlier when i first bought my mini, before i had really learned the gun inside and out..while you could have a defective poppit as stated, it could just be a pressure problem. try lowering your pressure a bit, i run 175-180 with stock bolt and spring, lower than that gives me blowback and higher than that gives me troubles as well. it was about 2 or even 3 years ago when i ran into this problem and it was bugging me so much i was gonna send the gun in, but before i did i tinkered, spent some time learning how the gun works, and was able to solve the problem on my own
follow the stickies and determine which version yours is, also look at the differences in poppits between versions. if you have a v2 then you should be able to solve the problem by tuning the gun properly. if you have a v1 with the small hole then talk to kee about a new poppit...
PURE invert mini, foregrip extender,Tadao circuit board, Dynasty champions CP barrel, NDZ bolt and spring, Relay on/off, Cp trigger,
blue virtue lazer eyes,virtue grips
some sports make you put your balls in a basket, others over the fence, or a catchers mit. sometimes with a swift stroke,
you whack your balls over great distance to drop them down a hole...
personally, i stuck with the first sport that let me put my balls RIGHT IN YOUR FACE...