Galaxy MP5K trigger not returning consistently

[Rogerborg]

I've searched, but I can't see this specific issue being addressed.

My new Galaxy MP5K is shooting fine, but has an annoying trigger issue.  First, it's a verrrry long pull, which I believe is characteristic of these boxes.  The problem is that when I shoot semi auto, the trigger doesn't always return.  If I do a quick squeeze-and-release it usually bounces forward fine.  However, if I pull it all the way back, hold and then release, it often just sits there and needs nudging forwards until the spring tension completes the job.

More info, it only does this when actually cycling the motor.  With the battery out, the trigger always returns.

I'll be diving in there to see what's up, but if anyone has some experience with this issue, it'd be great to have some expectations of what I might find.

 

[Iceni]

Is it shooting full auto when it locks? If it is it's the trigger contacts been too tight.

If it shoots once then locks I would look at the cut off lever and the trigger dolly. It might be a burr or a sticking cut off not allowing the dolly and trigger to reset. Or the legs on the dolly are a little long and are fouling.

Also check there is a cut off lever return spring in place. It could be as simple as the spring is missing and the cut off isn't resetting. So it kicks the trigger but then holds up the dolly.

I do believe I have read about the whole switch/contact assembly on some Mp5 boxes been sub par and replacing the trigger unit for a better constructed model fixing the issue.

 

[Sitting Duck]

Sounds like a similar symptom to broken trigger spring.....

on auto the trigger returns coz it gets pushed back from trolley

(trigger is still latched onto trolley, so gets shoved back with trolley spring)

BUT when COL pops trolley off trigger, the trolley goes back and stops firing

but the trigger sits there until you manually return it yourself

I say it SOUNDS like a broken spring but it seems to work sometimes

plus it works with no battery - which is a bit odd - mystery deepens ????

(Actually no battery = gun no cycle so trolley doesn't pop trolley so returns with trolley/shuttle)

But you say it sometimes works

But my initial thoughts a burr or catching on trigger return spring

but them trigger springs are not lame springs - they are bastid springs jumping out at first chance

BUT the initial SYMPTOMS sound similar to broken trigger spring

you gotta a two part trigger - hence the long pull on v3's

bespoke fire selector with built in safety tab that locks the trigger

but reckon the trigger's operation is worth paying close attention to

one of the two parts could have a burr and be catching or restricting its return

(more so when gun/box is cycling for some even more bizarre reason)

might need scooby doo for this mystery - bet it was them meddling chinese kids that assembled it

or

a priest coz sounds like it is possessed

busted spring or likely slipped out of place perhaps or burr/catching/restricting smooth trigger

Samurai is correct - these Galaxy's are really - no really just chucked together very often

We might moan about China guns crap assembly & QC - but these are one of the worst

this is their top tech bloke.....

 

TBH if you had asked I'd have probably pushed you towards a Cyma one or something

(or titchy big bro G3 SAS T3 mofo, 220mm barrel 500 rnd mag v2 box no stock/folding stock)

Shimmed rough, on investigating the tiny grub screw

on fire selector lever mechanism busted as I tore it apart

some boxes inside have full rails - mine had barely any rails - WTF !!!!

Full rails.......

& BABY RAILS....

look really carefully by the back of piston - WTF ???

Think they made a few revisions over the years but the QC does suck more on these cheapy guns

keep stock nozzle if possible, they do not take normal mp5k nozzles from SHS

in fact a SHS RED M4 will work BUT is too fat at shoulder to fit in hop unit

So you file/mod the nozzle shoulder a bit so it fits or mod hop unit opening to accept red m4

Or find a nozzle about 21.4 to 21.5mm that fits

see if you got an old cylinder head with fatter spout so stock nozzle fits more snuggly

(if it is really really loose - but don't order a shs mp5k nozzle coz it don't work)

read description here of using a Red M4 nozzle for Galaxy MP5k....

http://www.clandestineairsoft.com/shs-nozzles-c-1_6_75_77/shs-aluminum-mp5-oring-nozzle-1781mm-p-23.html

now the SHS MP5k nozzle might work ok (just if you shave tappet plate front)

http://www.clandestineairsoft.com/shs-nozzles-c-1_6_75_77/shs-mp5k-aluminum-oring-air-nozzle-2108mm-p-858.html

Just saying this Galaxy is a bit qwirky and poorly assembled in most cases

So double check nozzle length before you buy one or work with what you got

yup battery room is bloody tight too - jeez that stick battery & others don't fit easy

so be careful measuring up other batteries to buy coz it's tighter than a camel's ar$e in a sandstorm

 

[Samurai]

Sounds like something is too tight around the cutoff lever/trigger area.

It's a Galaxy so it would benefit greatly from a clean up and reshim. Check where it might stick. Probably the cutoff and trigger trolley because it's only happening when it actually shoots = the cutoff moves.

Yes, the long trigger pull is a feature. The v3 box has the trigger's axis way higher than the v2 but the mp5 body needs the trigger to be lower, so it's very long.

 

[Rogerborg]

Is it shooting full auto when it locks?

No, it shoots fine.

Sounds like a similar symptom to broken trigger spring.....

Could be.  Although there is some spring tension in the trigger, but it's quite light.

I say it SOUNDS like a broken spring but it seems to work sometimes

plus it works with no battery - which is a bit odd - mystery deepens ????

That is the puzzler.

BUT the initial SYMPTOMS sound similar to broken trigger spring

you gotta a two part trigger - hence the long pull on v3's

bespoke fire selector with built in safety tab that locks the trigger

but reckon the trigger's operation is worth paying close attention to

one of the two parts could have a burr and be catching or restricting its return

(more so when gun/box is cycling for some even more bizarre reason)

Could be.  I imagine it'll be obvious enough once I have it apart, and I'll report back with my findings.

TBH if you had asked I'd have probably pushed you towards a Cyma one or something

(or titchy big bro G3 SAS T3 mofo, 220mm barrel 500 rnd mag v2 box no stock/folding stock)

I was tempted by the CYMA, but more tempted by the £71 price on the Galaxy.  Then I was verrrry tempted by the shortie T3s on sale at GunFire, but the lack of G3 magazine availability and choice put me off.

The Galaxy does actually shoot decently enough on full auto, and is a great laugh as a sniper secondary.  Sadly, it also needs to serve as a semi auto CQB primary so I'll need to get this figured out.

yup battery room is bloody tight too - jeez that stick battery & others don't fit easy

so be careful measuring up other batteries to buy coz it's tighter than a camel's ar$e in a sandstorm

Already LiPo'd.  They are still a bit of a squeeze, mind, and once I'd put a Deans connector on it, I realised that the Deans on the batteries wouldn't fit past the faux slappy-bolt, so most of that had to get hacked off (so no returns now )

Sounds like something is too tight around the cutoff lever/trigger area.

It's a Galaxy so it would benefit greatly from a clean up and reshim. Check where it might stick. Probably the cutoff and trigger trolley because it's only happening when it actually shoots = the cutoff moves.

Yes, the long trigger pull is a feature. The v3 box has the trigger's axis way higher than the v2 but the mp5 body needs the trigger to be lower, so it's very long.

That's what I'm hoping.  There is some spring tension in there.  To be honest, I might just give it a blast of silicone oil and see if it frees up before tearing it apart. Heresy!

 

[Sitting Duck]

Could be.  Although there is some spring tension in the trigger, but it's quite light.

That light tension is just the trolley spring perhaps....

Normally - you pull trigger and you are pulling BOTH trigger AND trolley spring tension

when trigger spring slips/breaks you got a lot less tension at pull of trigger

(and trigger don't return when trolley pops on semi, so you have to manually return it)

But still you may not always notice it at first - especially as it all works OK on auto

even if you think you know your gun - but when investigating.....

Ohhhh yeah - thought that trigger felt a bit light....

Might not be what I'm suggesting but it does sound very similar

so investigate around trigger/COL as others said

G3 mags do come & go but usually somebody has them in stock

500 rnds - you don't need loads & loads of them just a spare or two will do ya

If you got something like the Echo One GAT or others:

https://gunfire.pl/product-eng-1152205869-FC-SMG-Submachine-Gun-Replica.html

then YES you really need to ensure you can get hold of mags like hen's teeth

 

[Rogerborg]

That light tension is just the trolley spring perhaps....

Normally - you pull trigger and you are pulling BOTH trigger AND trolley spring tension

when trigger spring slips/breaks you got a lot less tension at pull of trigger

(and trigger don't return when trolley pops on semi, so you have to manually return it)

Hmm, that does sound very plausible.

What's my best bet if I have a broken spring?  https://springsandthings.me.uk/product-category/tension_springs/ ?

 

[Sitting Duck]

Hmm, that does sound very plausible.

Worst case, if I have a broken rather than just slipped spring in there, what's my best option to replace it without paying half the price of the gun for a tuppence piece of wire?

SOME spring sets include trigger spring

SOME don't include the trigger spring

think SHS v2 spring sets don't have v2 trigger spring

but ZCI v2 spring set does include trigger spring

however SHS v3 spring set SEEMS to include v3 trigger spring

BUT ZCI v3 spring set does not

SO CHECK WHAT STUFF IS IN THERE BEFORE YOU ORDER !!!!

About a fiver just over say on fleabay

alas Pete AK2M4 is out of stock

https://www.ak2m4.co.uk/internal-parts/misc-internal-parts/ra-spring-set-v3

(bottom right is trigger spring btw - quite chunky spikey f*cker)

maybe this one.....

https://www.ebay.co.uk/itm/Shs-V3-Gear-Box-Spring-Set-Shs-Mech-Box-Airsoft-Aeg/182674169550?hash=item2a883a9ece:g:WikAAOSwnTxZbi5t

 

[Rogerborg]

Ah, super, thanks.  Of course, diagnose first, then throw money at it.  It's just good to know that parts are available if needed.

 

[Sitting Duck]

it might have just slipped off or they forgot to include it

not all highly trained Galaxy techs have great eyesight as I said

when I took mine apart this grub screw broke - actually broke !!!

had to muller it off and get a new one....

I'm not a great fan of them myself (as you can tell)

maybe be I got a lemon but I wasn't impressed with it considering other guns up to £100

Don't think they could make it any cheaper or it would start falling out of cereal packet

yeah might not be very ethical giving it away as next toy in McDonalds Happy Meal

(well maybe in 'murica it would be perfectly normal)

 

[Callum Hornsby]

Definitely sounds like trigger spring. I had the exact same problem my trigger spring snapped. In full auto the gun functioned fine but semi I had to manually pull the trigger forward as it was not resetting. Needless to say there is a certain frustrated feeling one gets when you have to spend £7 in my case for a single spring but o well  :lol:

 

[Rogerborg]

Real life got in the way and I didn't have time to disassemble tonight.  There is definite return spring pressure all the way through the travel, but (battery out) I can feel a slight notchiness about half way through the return, in semi-auto only.  I've scooshed judicious amounts of silicone spray in and to my surprise it actually helped and there's a noticably smoother pull and return.  Although I haven't tried firing it yet, and in any case bodges usually last right up until "3... 2... 1... GO" in the next game.

Sight unseen I'm guessing at a burr that's catching on the return rather than a missing spring.  I'm in two minds about disassembling it this week since I can run it as-is in full auto on Saturday, as opposed to not running a semi-auto, semi-reassembled gun.

Maybe I need to buy another backup gun to my backup gun, so that I have some safety margin...

 

[Sitting Duck]

Maybe I need to buy another backup gun to my backup gun, so that I have some safety margin...

Careful, that is exactly how many of us got started

 

[Rogerborg]

Well, I just infected my workmate my loaning him my CYMA while I played sniper + MP5K. He's got a G&G Raider on the way, so now we can find a third victim... 

OK, sorry to be the bearer of simple news, but that spooge of silicone seems to have done the trick.  Smooth pull both ways now, with sufficient spring tension to return the trigger consistently when shooting semi.  I don't really have an excuse to strip it down and see what's up, and if it is just a slight burr then my hope is that it'll get better with use.  Let the pewing continue.