Dry fire | feeding issue

[GadgetActual]

He guys,
I have a dry fire issue. My replica in single shot doesn’t allow BB’s to be shot. In burstmode sometimes a bb is shot sometimes it is not.

My replica has a Noveske MUR Madbull receiver with a Lonex gearbox with m120 spring. Both of them are brand new. The hopup is a Madbull ultimate hopup with a blue bucking.
The motor is a Lonex A1 Titan I tried 11.LiPo and 9.6 NiMH

This what I’ve done. Test the replica with 6 different mags (all the same issue)
Took the innerbarrel with hopup from the replica and inspected the hopupbucking (nicely round)
Put a bb in the hopup (the bb is hold by the bucking and with a little pressue travles trough the hopup and barrel)
Put the hopop onto a magazine (the mag is feeding the hopup)
Put the barrel back inside the replica and inserted a magazine ( the magazine is feeding the hopup)

Seam to me there can only be an issue with the nozzle not retracting far enough for a bb to be allowed from the hopup feeding magazine tunnel into the barrel.
However I’d like to read your thoughts and solutions to this problem.

Thanx in advanced

[Edit]
I forget to mention I shoot both Extreme presission and HIDD bio's (non bio's arren't allowed in my county)

[Rusty Lugnuts]

have you confirmed that the nozzle moves back and forth when the mechbox cycles?

[GadgetActual]

Originally Posted by Rusty Lugnuts

have you confirmed that the nozzle moves back and forth when the mechbox cycles?

Hee Rusty,
Yeah; Heled the replica upside down and the nozzle is moving backwards and forwards.
I don't know if it retracts backwards enough for a bb to be loaded inside the barrel/hopup.
I gues somtimes it does because it fires but somtimes it doesnt fire.

It fires one bb, than it dryfires, this will reapaet most of the time but somtimes it dryfires a couple of times.

I just to the hopup completly appart and tested it. The hopup isnt jamming a bb as I tought by looking at the fire, dryfire cycle.

[lurkingknight]

if it was a preassembled lonex gearbox I've heard the tappet plate could be a bit too long. When the shot does come through it does it shoot full fps that the gearbox is rated for or does it just kind of drop after 10-15m?

[GadgetActual]

Originally Posted by lurkingknight

if it was a preassembled lonex gearbox I've heard the tappet plate could be a bit too long. When the shot does come through it does it shoot full fps that the gearbox is rated for or does it just kind of drop after 10-15m?

It was a preassembeld box:
http://www.lonex.com.tw/english/engba-05.htm

The bb's that are shooting do so at arround 400 FPS I think that's just like I can expect from this box.

[lurkingknight]

what motor and battery combination are you using with it? If it's too fast then you may need a sector clip.

if it's shooting as expected fps then the tappet is probably not the issue then unless the stroke is too short by a hair and can't open wide enough for the BB to come in.

Try filling your mag and in a plastic bag with the mag oriented the way it would be in the gun, and open the retainer... do the bbs explode out or do they kind of poo themselves out?

[ThunderCactus]

Did you try different BBs?

[Stealth]

If you got your gearbox sometime between January and June 2013 then chances are you're going to need a new tappet plate.

Where did you get your Lonex box from?

[GadgetActual]

Originally Posted by Stealth

If you got your gearbox sometime between January and June 2013 then chances are you're going to need a new tappet plate.

Where did you get your Lonex box from?

Yeah is did get it in that time. I buy it from WGC shop. It is good to hear it it a problem well known to you and not my lack of building this replica.

[Stealth]

Any tappet plate will work, you just have to make the necessary relief cuts to fit the mechbox. It'll make sense when you have the tappet plates in front of you.

[Rabbit]

Good picture references in this thread - following this fixed my issue completely - I used a king arms tappet plate instead of the SHS shown

http://airsoftcanada.com/showthread.php?t=156011

[Zab]

ya try different bb's, i remember when i started out i didnt wanna pay $25 at the airsoft store so i went to canadian tire and bought cheap black .20 for $15... Well guess what i should of burned that money instead cause they wont feed. You have to use hi grade polished silicone bb's, even more so in a higher end weapon.

P.s Any one wanna buy 5000 black CT bb's lol

[ThunderCactus]

*Styrene BBs

[GadgetActual]

Thanx for the info on the Lonex-mod. I've looked into this threats and orderd a:
MDF-GB-05-12 MODIFY Polycarbonate tappet plate (V2 Gearbox).

As soon as is comes in and I'm done with the mod I will post if this mod have solved my problem.

As for the BB's I use:
http://hidd.be/catalog/en/content/8-hidd-bbs and
http://www.greendevilbb.com/

Will look into some others as well

[Kos-Mos]

Did you try to put some BBs in the hop-up unit, with the gun unside down, and fire?
If it shoots perfectly all the time, it's your mag. The BB catch at the top might be too long, or the feed tube of your hop-up unit is too short. In both cases, shaving the very tip of the BB catch usually solves the issue.

If it does not, it's your tappet plate or nozzle.