There are two possibilities that I can see:
1. The spring is not getting enough compression for the plunger to engage the catch. In that case, cut a coil off, and try priming again.
2. Simply replacing the stock catch spring with a pen spring isn't providing enough force for the catch to hold the stronger spring. Try doubling up your catch spring by using the stock catch and the pen spring. If that still doesn't provide enough force, maybe add another spring, or buy a stronger one at a hardware store. However, you can't add too many catch springs to the catch; otherwise, the springs may not get enough compression for the catch to engage the plunger.
Good luck, hope this helps.
EDIT: If you simply can't get your Maverick to catch after trying to solve the issue, you can just use the "penny mod". It is a tried and true method of getting better performance out of your blaster.
Personally never looked into a Maverick in my life, nor do I remember even holding one. Probably should get around to finding one, if I can.
I have my suspicions that the two springs might be binding, since both have their coils wrapped in the same direction, and it looks like they both are around the same diameter. If it is the springs binding, there isn't really a good solution other than finding another spring with a smaller diameter or one wrapped in the opposite direction. It could also be one of the reasons Bubba mentioned.
Check to see if you are completely reaching the full draw. If you cannot draw the slide back fully, then it's a problem with the main springs. If you can rack the slide completely but it goes back, it's a problem with the catch.
Hope something helped.
I think the springs are binding. In that case, would it be appropriate to cut a coil off?
plunger head destroyed, the o ring won't stay on so it won't work. This is because you removed the air restrictor which was unncessary IMO.
That's the black ring,
I see you already got a stage 1 OMW kit, you may as well get stage 2 at this point
What should I do? I didn't really understand what you meant.
P.S. Does this white ring help?image.jpg110.06KB46 downloads
(dart added for size comparison)
It looks interesting, but the rules state that only unmodified Nerf Zombie Strike blasters are allowed. I bet that's going to be a turn-off for a lot of modders here.
On the other hand though, they will have an event where I live (Kansas City), and not many Nerf Wars take place here.