Balls Deep - BBs shooting every second shot

[Rabbit]

So im in balls deep - have a milsim Saturday that i'd like to have this AEG ready for. Although its just a back up i'd like to have it on hand anyways.

King Arms Gearbox using genuine pmags im having bbs come out at normal FPS but every second bb missfeeds and nothing shoots. Once in awhile i get a drip bb out the end of the inner barrel as well. Standard checks on the hop up sleeve and alignment have been done. No airleaks at a consistent 398fps.

I recently put in a SHS 13:1 gearset with a SHS hitorque - although I figured i didn't need a delay clip so I left that out of the equation. Im using a 7.4v just because I haven't bought any 11.1vs just yet. You should only consider a delay clip at 33rps no? Im only curious about the delay clip because it helps the tappet plate come back a bit further and im curious if this would solve the feeding.

My first assumption is the nozzle going too far into the hop up - ive actually swapped the king arms for an element and I think it may be a little longer causing the jam.

The one oddity is that upon switching to another pmag in my pile the results seemed to vary even more and when using a MAG brand magazine no bbs fed whatsoever.

Anyone come across anything like this?

[lurkingknight]

the line is a bit fuzzy when you need the sector clip. It's in and around 30rps though.

If you drop rounds in the feed tube upsidedown, does it feed?

13:1s and a big enough 7.4 and you're close to 30 rps, if not over.

The KA nozzle also seems to be a bit shorter than other m4 nozzles, I had an issue with a shs nozzle in a stock KA, it dropped a lot of fps.

[Rabbit]

Upside down I just get straight up jams no feeding at all, actually a bb gets stuck in the hop up and I have to fish it out.

I had the same issue with an SHS nozzle, which is why i swapped for the element which is a bit longer by appearance (only bought a digital calliper recently to verify shit like this)

Shit. Maybe i'll try the stock delay clip that was on the original ka gearset - whats with all the variations in shape when it comes to these things?!? Looking online how do you know what to buy??

Edit: I should also mention the firing of every second bb only happens in semi - on full auto I get no feeding or bbs shooting whatsoever.

[lurkingknight]

I'd be suspicious of the nozzle... what's wrong with the original one?

if the nozzle was sealing well, it should be firing as long as the BB makes it into the chamber.

if it feeds in full auto, then you probably don't need a sector clip... but it's not going to hurt with 13:1 s in there... especially if you're going to put in 11.1v lipos.

[ThunderCactus]

are you sure it's not the mags?
Also, you're going to be using an 11.1v later? You're going to have even more problems lol

[Rabbit]

I have only the two sets of magazines sadly - MAG brand and genuine pmags.

The MAG brand feed flawlessly in my VFC - put them into then KA and no bueno - no feeding or bbs firing - although they click perfectly into the magwell and stay in place when tugged on.

PMAGs fit snug into the KA although I get variations from mag to mag, some fire a bb every second shot, some dont feed at all - all of them however do not fire on full auto

PMAGS do not fit into the VFC magwell (Umarex 416)

Im pooched.

The 7.4vs I have are 15c discharge and 1400mah but I still get the snappy trigger response i was looking for, I was only thinking about the jump to 11.1v to maximize but thats a whole different discussion when it comes to some extra spending cash

[Wrath144]

Have you tried different BBs? Do you still have the stock nozzle to try?

[Rabbit]

Been testing with .20g bbbastards - sadly no other brand.

Im just at work but tossing the stock nozzle out sounds like something I would do if it didn't have an internal o-ring. :/

I'll give either one of these a shot tho - installing a sector delay clip and swapping out the nozzle. I figure those were the only two reasons this could be happening.

[Ron-E]

I would suggest checking your Sector gear clearance for the tapped plate. I saw a gearbox once that the sector gear was shimmed so high that it was creating a lot of friction on the tappet plate and was not able to move freely to the front.

[lurkingknight]

Originally Posted by Rabbit

Been testing with .20g bbbastards - sadly no other brand.

Im just at work but tossing the stock nozzle out sounds like something I would do if it didn't have an internal o-ring. :/

I'll give either one of these a shot tho - installing a sector delay clip and swapping out the nozzle. I figure those were the only two reasons this could be happening.

really? the stock KA nozzle I had issues with replacing had an o-ring in it.. it just didn't seal perfectly.

As a back up gun though, I figure it would be more important that it be shooting reliably than have absolute perfect seal.

[Red Dot]

I had a demonic KA rifle that was posing a lot of these types of problems.

With PMAGs you still might need to add some velcro inside the magwell at the rear (trigger) side to make it seat better.

I also noticed with using PMAGs that the followers inside that push the BBs tend to bind up a lot, I've since removed them and they showed much better improvement however I have not gamed with them yet.

Good luck.

[Rabbit]

Update: switched nozzles to something mildly shorter and adjusted shimming on the sector and installed delay clip.

Issues continued however there were times when I was getting consistent semi shots off.

Thinking I might chaulk this one up to a mag feeding issue.

FINAL EDIT: This issue was caused by the magazines - I put everything back in that I took out and tried some CYMA brand mid caps and all was well in full and semi firing.