TM Hicapa - singel trigger press = dumping mag in full auto

[MultipleParadox]

Another day fiddling with the Hicapa, another problem

So I have been rebuilding this gun for a while at a very slow pace;
Getting there, the only problem I've got now is this:

A single trigger press (then release), will dump the entire mag (or close to) in full auto, uncontrollably

Trying to figure out what could be the cause; Tried the search on here and google and couldn't find anything specific to this issue

Hammer / Knocker seem to act normally; Will lock back every single time, the knocker will retract, etc.

The only thing I can see right off the bat is the nozzle's return spring seems to weak to reliably return the nozzle in the bbu. If I pull it manually, it wont retract back all the way. Could this be the cause by any chance?

Gun is all oiled up

Parts:

- Airsoft MasterPiece slide and outer barrel
- Stock BBU
Also tried a featherweight plastic BBU; same issue. Actually worse (the nozzle is even more restricted in movement)
- Airsoft Surgeon Hammer Spring, Loading Nozzle & Piston Head
- Airsoft Masterpiece hammer and strut
- ILLusion Kinetics Hop Up Chamber
- ILLusion Kinetics Leaf Spring
- A-Plus Devil Strike Chamber

I might be missing a few upgrades in that list but that's pretty much what I recall...

Thanks for the help

[localfreerider]

check the lock work for the hammer

without the magazine in the gun see if the hammer says back after you pull and hold the trigger and cycle the slide.

[MultipleParadox]

Yup
Holding trigger, racking slide: hammer stays locked

[Styrak]

Sounds like your sears are sticking. Do you have the original ones? Is there since reason you changed them?

[MultipleParadox]

Not sure I do
Parts bin s quite a mess :P

When you say sticking, could you be more precise about what I should look for?

[Splinter]

Do you have 2 mags to verify either mag or gun issue?

[wind_comm]

isn't it usually the leaf spring that makes hi capas go full auto? bend your middle (sear) prong and disconnect prong to apply more pressure. most people building a race gun want the trigger lighter than the system needs to work right.

[MultipleParadox]

I doubt it's the mag but will try a second mag just in case

Wind_comm: may make sense. But if it were the case wouldnt the hammer not stay locked when doing the test described above? (Post #5). I rather not touch the leaf spring if possible as the tiniest change can make or break the gun, mostly :/

[MultipleParadox]

So, I tested with another mag, as expected I experienced the same issue

I forgot to mention I also had the WE disconnector in, which seems to have a better contact surface for the leaf spring

I don't have the sotck TM sear but had a Stock WE one

Tried the WE one, along with the WE disconnector aaaanand nooow it does seems to work fine!

Not sure if it really was the sear and or what (I did fiddle with the spring position, without bending the arms in any ways)

The only thing is that unsurprisingly the WE sear seems wuite finicky compared to the Airsoft Masterpiece one. Don't know how long it'll last in contact with the Steel hammer
I guess I'll eventually have to figure out how to mod the AMP sear in order to have it work correctly, oh well

But in the meantime, all seems good

Thanks for your help guys!

[shootersaber]

Originally Posted by MultipleParadox

Another day fiddling with the Hicapa, another problem

So I have been rebuilding this gun for a while at a very slow pace;
Getting there, the only problem I've got now is this:

A single trigger press (then release), will dump the entire mag (or close to) in full auto, uncontrollably

Trying to figure out what could be the cause; Tried the search on here and google and couldn't find anything specific to this issue

Hammer / Knocker seem to act normally; Will lock back every single time, the knocker will retract, etc.

The only thing I can see right off the bat is the nozzle's return spring seems to weak to reliably return the nozzle in the bbu. If I pull it manually, it wont retract back all the way. Could this be the cause by any chance?

Gun is all oiled up

Parts:

- Airsoft MasterPiece slide and outer barrel
- Stock BBU
Also tried a featherweight plastic BBU; same issue. Actually worse (the nozzle is even more restricted in movement)
- Airsoft Surgeon Hammer Spring, Loading Nozzle & Piston Head
- Airsoft Masterpiece hammer and strut
- ILLusion Kinetics Hop Up Chamber
- ILLusion Kinetics Leaf Spring
- A-Plus Devil Strike Chamber

I might be missing a few upgrades in that list but that's pretty much what I recall...

Thanks for the help

I think your finger pin got wrong installation. I mean this part!!! Check them one more time.