hop/feed issues

[Bullet]

Basicly on sunday the gun was being a dick. Its an A&K m4. Its by no means new but i love it all the same. Anyway i was advised to change the hop rubber and clean all associated items. I need alittle more info if possible.
I belive its a one piece hop but thats all i know.

Cheers Paul

[HunterAndy]

Re: hop/feed issues

What was wrong with it, symptomwise? Being a dick doesn't help too much haha.

[Bullet]

Re: hop/feed issues

1. It only chrono'd at 247 fps
2. the bb's were falling way short
3. it didnt want to feed

Thats it really.

[ThatblokewiththeScar.]

Re: hop/feed issues

I am just going out so will get back to you later but for now.

Split Hop rubber.

Air seal in piston.

Broken hop unit.

Broken damaged nozzle.

[bobtuskins]

Re: hop/feed issues

Has it been firing at that FPS only recently?
What was it last chronoed as?

If the spring is ok, it may very well be an air seal issue.
Misfeeds can be caused by a malfunction in the nozzle of a very very dirty hop. You may also want to install a sector chip in the GB.

[Bullet]

Re: hop/feed issues

It chrono'd around 320. Ill look into the rest of the probs too. Whats the best stuff to use to clean the hop/barrel??

[Wingmann]

Re: hop/feed issues

Without magazine, put the gun upside down and fire in semi. Look at the hop feeding tunnel. Does the nozzle retract properly from the chamber after each shot?

[Bullet]

Re: hop/feed issues

9 out of 10 times.

[ThatblokewiththeScar.]

Re: hop/feed issues

Silicon oil is what you need to clean just about every part of an airsoft gun. After Glasses, Battery's and BB's it's the next thing you should buy. :D

Is it now shooting at 320fps? What did you do to it to get an increase like that? And therefore what problems are you still having specifically?

[Bullet]

Re: hop/feed issues

no mate it was at 320 ish before sunday, now its below 250. I going to have a look at the hop rubber as its a 5 min job before i start ripping the gb apart.

[ThatblokewiththeScar.]

Re: hop/feed issues

Good place to start. Get back to us with the results.

Phil...

[Bullet]

Re: hop/feed issues

Will do. Thanks for the guidence.

[Wingmann]

Re: hop/feed issues

9 out of 10 times.

From the same position, can you move the chamber or is it rock solid between the gearbox and the barrel assembly? If there are gaps there -caused by misplacing or mags moving the hop unit- it would completely ruin the airseal and cause severe FPS loss.

[Bullet]

Re: hop/feed issues

I stripped it last night and its a two piece hop. So the bottom part is fixed with no movement. The hop rubber and bucking look fine. But the air nozzle can be moved all over the place it seems very loose. Could this be my problem??

[HunterAndy]

Re: hop/feed issues

If you can move it forwards and backwards freely- the return spring on the tappet plate has come off.

If it's wobbling around left and right as well your tappet plate is probably broken.

The nozzle should return to it's normal place if you push it in the gearbox slightly.