We m4 open bolt

[fredz126]

Right I have a ob m4 and my issue is the hop is all over the place. Keeps curling off to the right and about 10 shots keep curling to the floor??? I bought a A+ hop rubber and still the same. Also getting quite abit of gas coming out of the ejection port.
Any ideas guys. And yes the barrel is spanking clean lol

[Skolob]

Re: We m4 open bolt

if you barrel is clean (I found liquid brasso and a goo polishing got it propper clean) & you havn't got a defect in the barrel ( and he WE barrels are not that good, not very smooth bores, milling looks shite on all the ones i have looked at) then the hop unit or flash hider is the problem. most likely its the rubber or nub on the piss and slightly rotated right. BBS diving to the floor can be because the bb isn't spinning enough (too much and too little hop can cause this) generating reverse magnus effect. the standard hop nub is an oversized rubber block actioned on by a grub screw which isnt ideal. I swapped mine for an element H nub with two very fine shims to center it (in my g36 I used plasti card, I think it was a cut from the plastic bakers complete puppy food bag I used for my m16 [*1]). i would also check the rubber contact surface too in case its uneaven.


[*1] Also very good if cut a disc slightly smaller than a CD for replacing the diaphragm in a flushing toilet if it stops working. Lasted a couple of years so far