MP5 Systema mechbox ? Fit into Classic Army MP5
 

Does anyone know if you can drop in a Systema complete mechbox into a Classic Army body? Any modifications? Someone told me they're only compatible with TM guns!!!!

I don't think you'll have any problems - CA MP5's are based off TM's anyways, and parts are interchangeable. although I'm not 100% on the new CA "Brugger and Thomet" MP5's - I haven't had a chance to work on one of those yet. Be aware that you'll need to be running a large battery and full stock on the back; a small battery up front in the handguard will not push an M120 box for long.

Here's a reference, showing wire leads for the battery to the rear:
http://www.uncompany.com/pageproduct...sp?prodid=9141

Hey, what a coincidence as I'm putting together a CA B&T MP5 with a Systema S170 Magnum set. Of course I swaped out the 550fps spring for a 400 one.

So far the mech fits the body shell and hop-up pretty nice tight, the grip is a little off on the allignment but it's just a hair off over the motor hole but should be no issue from what I can tell so far.

I'm just waiting on some remaining parts to arrive and then I can assemble the entire gun. Yes, Skru is right, you'll need to use a large battery so the full stock is about the only good solution. A 9.6v NiCAD or higher is recommended

Feel free to PM me in a week or 2 for results :)

Cheers, Steve

Swapping out spring????
 

Why would you want to swap out springs? Too powerful for gaming? I'm not a gamer (not yet) but I want a powerfully moded one for my collection...and it happens to be the CA MP5A2. Looking to order a CA or G&P RIS system - stock plastic sucks!

Do you have any problems with your AEG firing full auto in the semi mode? Mine is brand new & misfires when you slowly pull trigger in semi mode??? Could it be selector switch? It feels a little GRINDY when toggling thru fire selection modes!

Most public events in Ontario (heck, Canada) cap AEGs at 400fps. 550fps from a full-auto gun is a bit... Intimidating. Besides, that high a spring creates all sorts of annoying issues, like needing a big battery.

Yep Saint is correct. I play at EOTEC where the field limit is 400fps and the s170 is just over kill unless I wanted to snipe. Not mention the wear and tear on my mech would be great, so running the 400fps spring in the ultra re-inforced mech should preform nice over time. I haven't tested the build yet as I'm still waiting for a selector switch to complete the mp5. If I installed the new spring correctly I should have no issues in FA or semi with a 8.4 to 9.6v large NiCD battery.

Sounds like your set up isn't alligned correctly... could be gears not shimmed right... could be problems with your trigger switch contacts being fried... could your motor pinion isn't sitting corectly into the mech, which means the height of where the motor makes contact needs adjusting... Best to ask a pro like ILLusion or another upgrader on ASC.

I'll PM you when my gun is done, with results. Good luck