ASG MP9 / KWA MP9 - Whats Your Experience + Help Needed :)

[H0bbsy]

Gday All!

 

I have recently purchased a used ASG MP9 / KWA MP9 which has had a little internal work done.

 

As I understand, these MP9s are notorious for internal bits going and so warrant some work here and there.

 

Whilst its fully functional currently, I was keen to purchase some uprated steel bits so that if it inevitably craps itself I can swap those in and keep it functioning.

 

Currently as it stands its got: 

`Lees Precision Gas Flutes (To keep tha power down).

`Wii Tech Outer Barrel.

`Wii Tech Nozzle.

`Wii Tech Light Trigger Spring.

 

I have had a gander on various forums / browsed exisiting listings and roughly compiled an attached list of what I think would be a good idea, but would massively appreciate any seasoned MP9 users opinions.

 

For reference, pew will be used on Green Gas Only (no hpa) and will be in semi only about 99% of the time. 

[Ronin0033]

I’ve had through my hands (at last count) 10 MP9’s, most of which were broken, so can make decent list of stuff you will need at some point. I’ll go through your list first:
 

Part 153 (disconnector) - yes, very much needed. The main MP9 point of failure! 

Part 151 (hammer release) - not seen a standard one break, but if you get a steel hammer, then get this too

WiiTech piston head - yes, but double check this doesn’t need to be used on the WiiTech piston chassis. 
Part 25 - not seen a broken one, I wouldn’t bother

Nozzle springs - yes, get 2 sets! 
 

My recommendations:

TNT Barrel set - so much better than the KWA hop unit

 

WiiTech Steel Hammer (part 26) - standard ones snap at the sides, sometimes will still function, but best to change to steel. Plus it’s a pain to change, so get this and only do it once! 

 

WiiTech Steel Action Bar (trigger bar) - I have one on mine and makes the trigger pull much better

 

WiiTech 130% Recoil spring - MP9’s can have issues if they don’t fully go into battery, this will solve that

 

A CowCow/LPE/WiiTech piston head. Anything over the standard KWA piston head. They dry out and crumble. Beware there are 2 different sizes of pistons and piston heads, 14mm (orange) & 15mm (green), so work out which you have. 
 

If you already have a WiiTech nozzle I’d get the WiiTech piston chassis. The WiiTech nozzle will destroy the back of the chassis eventually. Also the WiiTech nozzle is very difficult/almost impossible to change the valve on….

 

 

Hope this helps. Enjoy the MP9, it’s such a little beast ?

Edited August 13 by Ronin0033

[MrTea]

Bought my MP9 from @Ronin0033 and apart from the bolt getting stuck to the rear every now and then, it's been an absolute trooper.

I really only use it in CQB sites so i've never felt the need to get the TNT hop/barrel set but I would really like one at the stock barrel length but they're spendy and tend to be sold out pretty fast.

If you need mags, i'd suggest looking at retailers in Asia as they can charge as low as £33 per mag vs £50/£55 in the UK but the challenge is finding them in stock.

Edited August 13 by MrTea

[H0bbsy]

Thank you for the replies much appreciated. 

 

Think ive got a good idea what to do now! 

 

 

[EvilMonkee]

@Ronin0033  Any idea why my practically brand new KSC MP9 doesnt feed consistently?  It feeds and fire 3 or 4 then wont fire and I need to recock it

[Ronin0033]

Have you got different mags to try? Just check BB’s aren’t getting stuck where the lip meets the mag base. 

 

If the mag is ok, I’d check the nozzle springs are good and still attached. 
Also check to see if it’s fully returning to battery when fired. 
Best way to check is cock it with no mag in, and see how far forward the bolt moves when the trigger is pulled. It should only move a tiny bit, less than a mm, anything more than that it may need a stronger recoil spring to push it all the way forward. 

[EvilMonkee]

I think its a mag issue, I have a VMP9 mag which isnt as bad as the original one but still does it.  I am assuming you can file the inside down to make them not stick?

 

Edited Friday at 17:11 by EvilMonkee

[EvilMonkee]

@Ronin0033Been fiddling with it, the BBs are getting fed into the chamber so its not a mag issue, it seems that the mechanism isn't getting reset properly, so maybe the recoil spring is too strong and forcing the bolt into battery too soon??  Or could it be the classic disconnector issue, though surely it wouldn't fire at all then? Thoughts?

Edited Friday at 23:14 by EvilMonkee

[Ronin0033]

If you take the feed lip off the mag and just file down the bottom surfaces in the feed tube it should be good. 
 

If it’s still happening I’d guess it’s a nozzle or feed lip issue. If you are taking the feed lip off then gently file all the sharper edges of it, plus the feed ramp into the barrel. Everything around that area is very sharp and can chew BB’s. 

It won’t be a disconnector issue, the trigger will just go dead if that’s broken. 

 

Photos attached of where I gently file the top of my mags (also the inner parts of the lip) 

@EvilMonkeeSorry I’ve just re-read your original issue, didn’t realise you need to re-cock every few shots, thought it was just a feed issue. 
 

I’d check your hammer axles to make sure they aren’t broken. Unfortunately not easy to do without taking pretty much everything else out. 
 

Sometimes they crack but will still operate intermittently until it wears down the surfaces between. 
 

Here’s what they shouldn’t look like! 

[EvilMonkee]

Yeh they seem to be feeding into the hop fine but then not firing.  

Its my birthday Tuesday so will put in an order to WIITECH for the steel hammer and disconnector as well as the recoil spring.  May as well whip it all out at once and do it and then forget about it