M4 Air Nozzle Problem

[W@tchtower]

Hey guys,

So I just put all my new sweet parts into my m4 and I run a mag through it and it's the infamous sound of a jam, so I thought.

It would appear that my air nozzle isn't going forward enough, would this be true if I put my hop-up with a bb in it against my air nozzle and it doesn't push it forward? Is this a way to tell?

[ThunderCactus]

take your upper receiver off, cycle the gun so the air nozzle is in the forward position, and check to see if it moves back and forth freely.
If it does not, your sector gear may be shimmed too far to the right and it's pinching the tappet plate.

The problem could be much simpler like an incorrectly installed hop rubber, or your hopup is turned all the way on, or the wrong air nozzle, or you didn't torque things down properly when reassembling the lower receiver so the mechbox is on an angle

[W@tchtower]

The air nozzle moves freely and the box cycles. The barrel and hop-up are not an issue because i can put a bb in the hop-up, it will stay and I can push it through by tapping it with a pen. It is the stock air nozzle, so I am not sure if it can be a problem with that. My plan is to get a new compression spring since the one that came in the gun might not be the best one and may be failing to push the nozzle all the way. That or I want to file the back of the hop-up unit down a bit.

[JLiang]

Originally Posted by W@tchtower

It would appear that my air nozzle isn't going forward enough, would this be true if I put my hop-up with a bb in it against my air nozzle and it doesn't push it forward?

Originally Posted by W@tchtower

The air nozzle moves freely and the box cycles. The barrel and hop-up are not an issue because i can put a bb in the hop-up, it will stay and I can push it through by tapping it with a pen.

All your symptoms contradict. Would you care to elaborate?

Sorry if I'm of no help, but I'm confused as to exactly what's happening.

[ThunderCactus]

Your air nozzle doesn't push the BB past the air nozzle, it only seals against the back of it.

Did you install a new tappet plate? if so, what brand?

[W@tchtower]

Alright let me clarify, since I may have been unclear.

The box cycles perfectly fine: ie) the air nozzle moves back & forth & the gears cycle

The hop-up unit works as it should & there are no problems with the barrel. My question was is there a way to tell if the nozzle isn't coming out far enough?

I'm looking to file down the part of the hop-up that fits into the air nozzle or get a new compression spring for my aps v2 no2 gearbox. The tapper plate is stock & is undamaged.

[ThunderCactus]

Sounds like you just assembled something wrong, don't permanently modify anything on a guess.
Try taking the mechbox out of the lower receiver and putting it back in, tighten the grip screws first and the tailstock second.