Solution to "Sear not Catching/Bolt Won't Cock?"

I performed a bunch of maintenance and upgrades to my new Tippmann 98 Custom Ultra Basic. The day I got it I noticed it leaked air from where the line meets the valve body, but I couldn't figure out if it was the hose or the valve body. So I installed new ones of each and slapped in an e-trigger upgrade while I was at it.

New problem: after putting it back together, lubing the new bolt (not in that order), etc., it would dry fire only once. After that the sear would not catch the bolt; the gun would not cock again unless I slapped the butt with my hand first, and only then would it re-cock.

For the next few hours I tinkered and couldn't figure this out; it couldn't be a worn sear or bolt because both were brand new! Then, I took it apart one more time and noticed something: the actuator rod was magnetically attracted to my 9V battery, and as soon as I took the rear plate off, it would jump out out of the slot and stick to the battery. The next part of this post is a bit speculative (hence the question/title), because I can't see inside the grip when the gun is assembled and so am unable to confirm that magnetism was the cultprit, but I'd say there's a 99% chance it was.

Solution: move the battery as far as you can get it from the actuator rod.

As soon as I did this, the problem disappeared and has not happened again. I suspect that if you have something metal (like the battery) too close to the actuator rod, it will cause the rod to snug up against its slot, and the weaker sear spring that comes with the trigger upgrade is not strong enough to overcome the resulting friction. Other solutions might therefore exist: oiling the rod, getting another (non-magnetic) rod from somewhere else (local machine shop, etc.). Moving the battery far over causes an annoying bulge in the rubber/plastic grip, so I had to carve out a nook, hoping that I wouldn't carve all the way through my grip. It still bulges. But at least the bolt and sear work.

This was my solution and might not explain your problems, but I throw it out in case it helps someone. I ran out of air so I still can't test if my new gas line and valve body solved the leak problem! :( Mods: if this solution has already been posted, my apologies. I couldn't find it here.


Edited by SciFiGuy - 14 May 2014 at 7:16am