Toying with the idea of an LDT MP7… select fire option’s very appealing. 
Plenty of older online reviews on Youtube but keen to hear anyone’s hands on opinions of them. I’m aware that some had issues with the tappet return spring failing, geeking out the tappet plate, has anyone who uses one of these quite a bit found that to be an issue? 
@BME I believe you have one of these?
I would only get one to have as a collection piece, can not recommend using it.
A friend had one, the full rails kit and suppressor, hopup, flashlight, sight, spare mags and batteries; really went all in on it.
After a few months the return spring broke and he was quoted hundreds of dollars to fix it.
He sold it to me for a good deal considering it just needed labour a return spring.
I opened it up, found the design is such that the when the return spring breaks the tappet plate will be munted, so you need both. No big deal they aren’t that expensive. They are a shit show to work on. EVERYTHING except the o-ring is proprietary, and the process is fiddly and long winded. And if the ETU goes you have a nice wall hanger.
The build is decent, not great but decent, if you approach it as an AEP that is. They are an AEP after all.
Worth noting, it was decently shimmed, seal was very poor around the cylinder head but that is easily enough sorted, bang a green o-ring on there, and I think I also replaced the o-ring on the nozzle as it was a little loose. Otherwise I just replaced the return spring and tappet plate, cleaned and greased the thing and got it back together.
I felt it was a bit under volumed, keep in mind it is based on the airsoft gearbox, with a gel barrel so stuff all you can do about that.
I did program the bigrrrrrr thing to mag prime less, as once the mags were used it would prime for way too long and jam gels into the nozzle and tpiece and wouldnt fire again.
In my case, got it working, was as happy with it as I could be. After a week and a bunch of mags into my garage… and while I know there is a strange cult fascination with the MP7, I just didn’t gel with the platform. Sold it. Literally based on I never wanted to work on it again! Too many hours for too little IMO. Also at the time, was sold with a bit of profit as they were new, and it was noted that if the return spring and tappet was replaced they were lasting much longer than the original release parts.
I also have a BF v3? which didn’t have select fire but shot better, harder, and had better accuracy and consistency due to better volume. Yes it has had a spring, cylinder, oring, and nozzle/cylinder head. But it was easier to do, and still runs 11v fine with nylon gears. And if it breaks; it won’t as I never use it- see above not a fan of the platform comment… I have a spare gearbox that was $30.
Okay… sounds like not the one for me then. Cheers for that info, just what I need to know.
I don’t mind tearing things down now and then but if we’re talking parts failures it’s a big no.
The attraction was the BigRRR programable MOSFET, really. But it may see some light gameplay so I’ll look at other SMG oprions. Maybe a P90 with fire select. 
If only light use, I would say it would be okay, the only thing that really fails on them is the return spring and tappet plate, not sure if newer ones were fitted with the better parts. The replacements were SO much better quality than the standard ones.
If the mosfet does fail it is a grovel to WAT or a retailer for one, I haven’t seen one listed for sale as such.
Only seen a few people online over the time with them die, and it is likely they didn’t treat it like it had a standard grade of mosfet, you know: don’t use with flat batteries, don’t leave batteries plugged in when not in use, don’t leave out in the weather etc.
If only collecting it, and light use, it would probably be fine. I was mindful that I like to hammer my gear and while I have a degree of mechancial sympathy, I also like to get carried away and just have fun and not care about it breaking. Lack of parts for it is what scared me from using it more than I was worried it would need the parts, if that makes sense!
Apologies to @Friendly_Fire … i forgot to reply to this thread yesterday.
To add to the above, here are some performance figures…
BF MP7: a solid 200 fps unit. barrel could be lengthened slightly, and still fit inside the flash hider. it sits on 880 r/min, on a 7.4v batt. Build quality has improved significantly, and is excellent value for money , for a sub $200 blaster. Cheap gearboxes, cheap mags, plentiful parts. A no brainer if you’re into this model.
LDT MP7: Heavier in the hand. I saw a range of performance, on single fire between 260-280 fps. High of 300, low of 230. Impressive they can get so much, out of a small blaster. Mine’s had the upgrades done.
The mosfet works well, i never had any trouble with it…4 rnd burst replicates the pulse rifle burst…!!
I believe everything @RokSolid says about them being a pain in the arse to work on, and proprietry parts…
I also have a LDT UMP45. That does 300 fps out of the box, it must have a longer barrel. I dont know if its the same gearbox, but it also has the same mosfet. Maybe its a bit easier to work on, being a larger shell… @RokSolid do you have any experience with them?
Im guessing similar proprietry parts, but if they are still available, it should be ok. Still compact enough for CQB, with a larger mag, so maybe its worth considering…?
I just gave a UMP away 
I’m really looking for the smallest form factor with select fire. Keeps coming up MP9, MP7, MP5K, P90.
Someone on Youtube got 290FPS out of his Le Hui MP9. Of course, it probably went Chernobyl after a couple of mags. 
My metal geared BF MP5K is running 300fps but I still prefer the MP7 form factor - just haven’t picked up a select fire version. My old full auto MP7 version runs 280fps and has metal gears, upgraded piston full cylinder and a mag emptying rate of fire.
Sticking with the MP5K in games for the time being, until the lousy mag capacity sends me back to one of the shorty CYMAs
Yeah, I’ve been wondering if I should just be tricking up my CYMA with a few parts…
At least I wouldn’t need to buy any mags.
Had that keymod handguard on one of my CYMAs but swapped it for a 7" m-lock handguard with the suppressor partially inside the handguard
Thanks for the inspiration, Wombat. 
This little shorty will do. CYMA…
The gameplay I’ll be using it in is a private CQB session with a mix of players, all friends, a few women, the odd young teen. So by mutual agreement, target FPS is sub 250, preferrably around 200 to keep it fair and enjoyable.
With the shortened barrel and back to a 1.1mm factory spring, this little thing dropped from 310+FPS down to about 210-220.
PDW stock from X-Force and it’s done. 
Bang on, now you are talking. Irons, MOE VFG. I’ve got similar when I want to get shorty.
