LCT G3 DMR upgrade, V2 gearbox swap

[Baser]

I bought a used LCT G3 a few weeks ago with a plan to build it into a DMR. I don’t know a lot about the history or age of the gun, it doesn’t have a MOSFET or quick change spring. 
 

Original idea was to send it off to have it built into a 450fps semi only DMR with a few choice upgrades but I’ve come across a few V2 gearboxes (one made by LCT) with a MOSFET and quick change spring already part of the package. Will these just drop straight into the gun or need additional work to make them work?

The LCT version looks like the upgraded version of what’s already in the gun so should be fairly easy to swap over but I’ve also seen the Cyma platinum complete gearboxes. I have two Cyma Platinum MP5’s and they shoot incredibly well for what they are.  Both gearboxes are under £130 which seems like a cost effective option and basis for a good DMR build if it’s “that easy”. 

Interested in the MOSFET so I can program it to semi only and the quick change spring will allow me to tune the power and easily return it to a sub 350fps gun should I want / need to run as a full auto rifle in the future. 

 

[Lozart]

Based on general experience, the gearbox from the people that made the gun should have a better chance of fitting directly and working properly - but there are no guarantees.

The other thing I've found is that some V2 boxes in G3/G36/MP5 are subtly different than a standard V2 box (selector plate for one) so just check that before you drop coin on one. 

 

[Colin Allen]

Interested in the MOSFET so I can program it to semi only

Just be aware that many (most?) sites will not accept that and will require the gun to be mechanically locked to semi.

 

[The_Lord_Poncho]

I've achieved a mechanical lock in several ways, the simplest is superglueing on a fake domed rivet head (3d printed) to limit the movement of the selector switch. Seems to be accepted by the sites I frequent (albeit to be fair, so does an electronic lock via the FCU at those sites).

 

[Baser]

Just be aware that many (most?) sites will not accept that and will require the gun to be mechanically locked to semi.

Thank you I have heard this from other players as well.
 

I can put a small grub screw on the selector to lock it out if needed, currently only play 2 or 3 sites and they don’t have an issue with a programming / electrical lock out. 

 

[Colin Allen]

Thank you I have heard this from other players as well.
 

I can put a small grub screw on the selector to lock it out if needed, currently only play 2 or 3 sites and they don’t have an issue with a programming / electrical lock out. 

Well done to them; locking out via an ETU or mosfet should be acceptable.  I know that the argument against is "But you can reprogramme it."  However, how many sites actually check that DMRs really are mechanically locked?

 

[Baser]

Well done to them; locking out via an ETU or mosfet should be acceptable.  I know that the argument against is "But you can reprogramme it."  However, how many sites actually check that DMRs really are mechanically locked?

Most mechanical locks I’ve seen are just a screw or bolt in the selector which can be taken out.
 

It’s the same as adjusting power in the gun, yes you can change the spring or fiddle with HPA or put a different gas in your mags but if you do you are an idiot and deserve to be kicked out and banned. 

We play a game of honesty and trust, in fancy dress shooting people with toy guns.

 

[Colin Allen]

We play a game of honesty and trust, in fancy dress shooting people with toy guns.

That is exactly how I see it.