replacement is fine - 180 to 200fps. Has same lack of detent with fire selector and the rattling on sustained semi. It’s still good vale for half the price of the LDT and a good base to build it up
Would have they swapped it for a mp7, if you preferred them?
I reckon your right, pull it apart, upgrade, then you should be on solid ground…
Thanks, good info. Now I just need to make my bank account great again 
Already built an MP7. Might build MP7 after I’m finished with this one
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very good! I’ve still got to mail mine to them but should get to it tmrw.
picked one of these the other day and am quite impressed with the quality for the price.
For anyone intending on modding one, something to note is that there is no motor height screw(at least on mine). The stock motor shaft is longer than a standard 480 (compared with a warhead and xforce motor). I have tried both a metric threaded screw and grub screw without any luck as there is not enough plastic in the baseplate for the screw to hold.
I’ve temporarily overcome this by using a couple orings as spacers.
As for performance, as mentioned previously, it’s pretty dismal with the cylinder/barrel length combo. But is pretty easy fix.
Currently mine is running 16:1, warhead 20k, nylon slr cylinder (I think it’s roughly 70%) 7.5mm ausgel barrel & LDT hop up hidden with a short suppressor (barrel and hop is roughly 23cm and just what I had laying around that fit without having to measure/calculate anything) and a slr cylinder head /nozzle.
On a m100 it was doing fairly consistent 290-310, but have swapped to a m90 as I’ll be testing this weekend at a 300fps game
Other things I’ve found:
- LDT split box fits but the LDT tpiece is not compatible with the receiver/ won’t line up with the mag. The stock tpiece “may” work with the LDT box, you’d need to make some sort of spacer to prevent air leaks.
- MKTH h92 is compatible with the stock tpiece, however the lower receiver will need to be modified for the box to fit.
- LDT MP5 lower fits and lines up so could be an option if you can find one in parts bin somewhere and don’t want to cut up the stock jinming one.
- Retroarms, cyma metal and aps will all need the lower receiver modded to fit. The aps is the only one the stock tpiece will fit so the other two will have issues.
- Gen8/9 and slr cylinder head/nozzles fit with the stock tpiece but the slr nozzle seems to fit and provide a better seal.
- Gen8/9 spring retainer fits but a stock aps one with two tabs cut off fits better
- LDT folding stock fits but is tight.
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Wow, thanks for the detailed info. Guess I scratch that off my birthday list…
Tbh I was very surprised at how nice it feels for the price and I’d compare it to the LDT nylon MP5s at a fraction of the cost.
Another pro for this is how the mag terminals are. It makes for taking out the gear box so much easier without the worry of snapping spring terminals.
Even with the stock gears and motor it’ll only need a few things (cylinder/nozzle/barrel & spring) to make it a decent lil cqb performer. For mine it’ll probably end up being hpa’d. But for now will run it as I’ve listed with a change of spring for different fields.
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Hmm the good ole JM like to do things different seems to be still in play.
There is a introductory thread we encourage new members to post in if you can.
Thanks, far from new, was on the old forum, mostly just lurk in the shadows though.
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All good please yourself Not that there was anyone named Nam on the old forum.
Talk, dont Lurk…!!
We don’t bite…!!
Sounds like you can contribute a fair bit to the forum…!
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Ah, one more positive report for the Jin Ming… needs upgrades though? When have JM ever really made a blaster that didn’t? 
Based on this though it’s just inched a little closer to my shopping basket.
Thanks for the detailed info. Just got a couple of questions before I pull mine apart
- Does the stock gearbox have metal gears?
- Do you have to change the piston to fit a “normal” spring if using the standard box?
- Did you find any issues with motor height / pinion clearance on the stock gearbox?
- What gearbox and t-piece did you end up using?
Thanks - appreciate your input
- Yes stock gearbox has metal gears.
- Stock piston will accept other springs.
- If running any motor that’s not the stock one you will have lots of issues. The stock motor shaft would be a good 3mm longer than any aftermarket motor I have. I used two 2mm thick orings in the base plate to space a warhead motor (it’s not perfect, still a lil off but good enough).
- I kept the stock gearbox and tpiece for now and will probably keep them as I’ll more then likely end up putting a hpa engine in.
If you want to keep the blow back function you will need to keep the stock piston and cylinder. I don’t have any stock LDT pistons but they should work. Personally I don’t care for that feature so have disabled it (have to cut the tab off the charge handle that catches on the piston). Cutting the tab may remove the mag prime feature.
Also forgot to mention the LDT mag coupler will work but same as the stock is very tight.
I didn’t measure and just eyeballed it and somehow managed to retain magprime on the jinming. Can take pics and measurements when I get home for anyone interested. As for blowback have removed it from my LDT as well.
So what is the general consensus on minimum upgrades to this blaster - ie. the simple things.
I am guessing cylinder head (ported), 7.5mm barrel, o-rings.
I would think o ring and spring at a minimum.
Personally, and everybody’s different, whatever the techs like to call it, I call a FF minimum upgrade on any blaster that doesn’t already have these a non-factory o ring, M90 spring, alloy cylinder head, alloy piston head, alloy nozzle… if it’s apart you might as well do it all while you’re there and usually get me up in 290-300 territory.
Upgraded spring retainer’s not a bad idea too.
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Yup as @Friendly_Fire said those would be a min “standard” type upgrade I would/did do. You could get away with using the stock gears/piston combo for a while as long as you’re not pushing it hard with crazy spring rate or even a high speed motor.
For mine the piston/oring was actually decent enough for a stock blaster, but I did swap it out.
Make sure you calculate your cylinder to barrel ratio if swapping it out. For me the cylinder I swapped I know that roughly a 21cm-25cm 7.5 barrel pairs well. I think another issue from factory (and it could have just been mine) is the tpiece and barrel were not glued together.
Another thing to look at is the bushes. But this isn’t necessary straight away. In true jinming style they went with their 7mm cast bushes (could have been worse). Luckily I found some shs bushes I had from back in the day and swapped them out.