Really annoying problem.

[rjmcgough]

Hi, I play at a CQB site which has a semi auto rule. Recently my Mp5's Trigger has been "locking" after every few shots and I cant fire it. I have to change to full auto.Fire.Change back to Semi and it works again for a while then it "locks" again. I noticed a few peoples guns doing this. Is it just something I have to live with or is there a fix as it is really annoying?

[Airsoft-Ed]

It's generally because you're pulling the trigger again before the gun has completed the cycle from the first pull.

 

There are a few ways to combat the issue, the easiest of which is to use a higher voltage battery, but don't go higher than 9.6v without at least considering some other upgrades.

 

You could attempt to get rid of all the resistance between parts in the gearbox, shim the gears, make sure there isn't too much grease and make sure all the parts are seated correctly. This will mean that the gun can cycle faster, increasing the trigger response slightly, meaning there's less chance of you pulling the trigger before the gun's finished cycling.

 

You could reduce the electrical resistance in the circuit, which again will make the gun cycle faster, you could do this by rewiring with lower resistance wire, cleaning the trigger contacts with some sort of solvent to remove any build up of rust or whatever, or you could change the connectors for the battery to ones of a lower resistance. Most people swap to Deans connectors, but I've stuck with Tamiyas as I share batteries and they work fine for me. Making the circuit better is a giant faff though and the increase is barely worth the effort, I barely even noticed it whenever I've done it.

 

Lastly, there are upgrade parts you can buy to increase the trigger response, mosfets are a common one, these redirect the current directly to the motor, away from the high resistance parts of the trigger mech.

You could also change the gearing to a set that will spin faster, or you could buy a better motor, either high speed or high torque.

 

You could also put a lower power spring in the gearbox so that the motor doesn't have to work so hard to pull the piston back.

 

That's about all I can think of, but there's probably other things you could try.

[Liam Porter]

To add to what Ed said, I've found that a higher mAh battery will give a faster trigger response and less gearbox lock ups.

[rjmcgough]

Hi, thanks for the help. My gun is completely stock so I'll spend some money on some better internals and see if it helps. if it doesnt then it doesnt matter as I need better gears and such anyway.