TM CA Compatibility

[ShaneF]

I am looking at getting a complete CA mechbox for my TM AK but all I want to know is are they compatible?

[Muffin]

Yes.

[ShaneF]

Good to know. Thanks.

[namloot]

Yes, but you would probably wind up with a better product if you kept the TM GB and just upgraded it.

I put the following parts in my stock TM gearbox:

Guarder SP120 spring
Guarder standard gears
Guarder steel bearing spring guide
Guarder cut off lever
G&P polyacetate piston (white)
G&P piston head (non bearing)
Systema piston head O ring
DeepFire bushings

I have 36,000 rounds through the gun. The stock TM EG700 motor burned out after 20,000 rounds, I replaced it with a G&P M120 motor.

The gun shoots 425fps w/ .20g BB @ 23bps with a Sanyo 9.6v NiCad battery.

My upgraded/custom TM AK47:

[atple]

Deepfire Mechbox

[Crunchmeister]

Originally Posted by namloot

Yes, but you would probably wind up with a better product if you kept the TM GB and just upgraded it.

CA mechboxes are much higher quality and far more durable than the stock TM shell. CA are reinforced, TM aren't. I'll take even a JG reinforced shell over the weak TM shell. TM mechboxes will last forever as long as you keep it completely stock. Start upgrading with high velocity springs and such, and they don't hold up very well at all.

That being said, TM V3 mechboxes are tougher than V2, but I'd still go for a reinforced CA anyway.

[smurata1]

Through my experience CA Yellow Pistons and CA Tappet Plates can be trouble spots. I've had multiple incidents with those parts failing. Even using Marui OE parts as replacements is acceptable in my opinion.

[Crunchmeister]

TM generally make good internals. Their gears are weak for high speed or high power applications, but the rest of the internals are good stuff. The mechbox shells themselves though, I wouldn't trust to last any significant amount of time in an upgraded gun.

As for CA, I've honestly had better luck with my CA parts than with the Systema replacements I bought. I used the gun stock for about 20000 rounds before first opening it. From everything I had heard about CA internals, I expected pretty much all the compression parts to need replacements, so I ordered a bunch of new parts to isntall at the same time I'd open it to clean it and install a stiffer spring.

Turns out I had zero wear on anything. The piston teeth were perfect, and only the slightest amount of wear on the part of the tappet plate where the sector gear nub contacts with it (both stock CA yellow parts). Despite that, I installed a bunch of new Systema parts (no Area 1000, all real Systema). I installed a bearing spring guide, polycarb piston, silent pistion & cylinder head set, new airseal nozzle, and a new tappet plate. I topped that with a Prometheus MS110SP spring.

The new Systema piston lasted all of 250 rounds before snacking on itself and self-destructing. So I reinstalled my stock CA piston I had kept as a "just in case" part. I used the gun for 2 games after that, so about 500-600 rounds at most before the tappet plate snapped. So I had to reinstall the stock CA one, since I had it lying around, and there was nothing wrong with it.

The gun has seen 1 skirmish and 2 large, high action games (Op Drug Bust and Border Wars) since the old piston was reinstalled, and Border Wars + 1 skirmish since the old tappet plate was reinstalled. And a LOT of plinking. I had the box open a few days ago to clean it out and the CA parts still show no more wear than they did before. I'm quite pleased with the CA internals so far.

[Donster]

kinda off topic, but does anyone know if a Magpul M4 receiver will fit on a CA M15A4?

[Styrak]

It should. CA and TM bodies are compatible, minus the one or two piece hopup change.

[namloot]

Originally Posted by Crunchmeister

TM generally make good internals. Their gears are weak for high speed or high power applications, but the rest of the internals are good stuff. The mechbox shells themselves though, I wouldn't trust to last any significant amount of time in an upgraded gun.

My upgraded TM AK47 has 36,000 rounds shooting 425fps w/ .20g BB @ 21+bps (now 23bps with the new motor/Deans), all with the stock TM gearbox shell (and all other upgrades I listed above).

Their shells are fine.