UTG MP5 AEG Dissected! Quite impressive really...

[staticzero]

UTG MP5 Table of Contents

 

1. Overview and Initial Impressions

2. TM vs UTG Body Comparison

3. Hicap Mag Examined

4. Rewiring Guide

5. Front Sight Examined

6. No Modification 9.6v 1650mAh Custom Battery for the Full Stock or Aftermarket Handguard:

a. About the Battery, and Installing in the Handguard

b. Installing in the Stock

7. Noteworthy Links

 

 

 

For those of you that aren't familiar with this new MP5 AEG by UTG, I'll give you a brief overview. Basically, it's a near-exact copy of the TM MP5. It should be compatible with any part that's TM-compatible. It comes with two MP5K double mag style hicaps, a claw mount with side rail, both an A4 and A5 stock (sliding and solid), an 8.4v 1100mAh NiMH battery made with KAN cells, a (rather poor) sling, and a slow charger. All this for around $100 currently.

 

$100?? It's got to be a POS, right? Well, we'll see. Mine arrived last night, and I wasted no time getting to know it first before savagely violating the poor thing... Lets take a look (Because of the ten-pic-per-post limit this will be multiple parts).

 

Because there's more general info available in other threads, I'm not going to go into that kind of stuff. I'm also not going to spell out how to take the thing apart, there are plenty of guides out there that cover that. Moving on...

 

Here's the body stripped to bits. The upper receiver and cocking tube have a nice matte finish. The lower is on par with the TM. The handguard's finish is actually better than the TM's, in my opinion. It's much flatter. Both stocks are quite nice, though the solid stock's butt plate isn't rubber like the TM's. The whole body feel is quite solid overall.

 

The lower receiver.

 

Here we can see some wear from moving the selector lever.

 

Here we can see the screw that holds the retaining plate in is protruding. This is partially to blame for the selector lever's bad feel, and what's causing the marks in the above picture. More on this later.

 

The rear sight. The sights are the poorest plastic on the gun, the rest is quite nice. The sight is not adjustable, but the drum does rotate to allow for different apertures.

 

Cal 6mm BB markings.

 

The hop up chamber. It actually works well, and BBs feed nicely. No double-feeds.

 

Hop up chamber again.

 

The gearbox. Looks good, doesn't it?

 

The screws. They appear to be self-tapping. BE VERY CAREFUL, do NOT over tighten them, mix them up, or cross-thread them. You WILL destroy the threads in the gearbox.

[staticzero]

The gearbox opened up.

 

The gears.

 

The seal between the cylinder and cylinder head, and the cylinder head and nozzle is good.

 

Tappet plate and trigger assembly. The tappets appears to be the best plastic part in the gearbox, which is as it should be.

 

Cylinder head.

 

Cylinder head, tappet plate, and nozzle.

 

Piston head and piston. The o-ring is kind of shoddy. It's very rough around the edges. The compression is poor, and I suspect this is why. Try replacing it with a better one and re-lubricating the cylinder, should get a decent FPS increase that way.

 

Piston head and piston.

 

 

Cylinder, piston head, and piston.

 

Spur gear and anti-reversal latch.

[staticzero]

Bevel gear.

 

Sector gear.

 

Spring guide. Note the lack of a washer.

 

The motor. Looks good. But is it powerful? We'll see...

 

Handguard pin. Note the rough casting lines. This causes the pin to be really hard to remove from the handguard.

 

Here you can see I cleaned up the casting lines with my dremel. It comes out and goes back in smoothly now.

 

I tried to fix the selector lever feel. Here I removed the offending screw.

 

Here we can see the screw is more than capable of sinking in to the plate properly. It must be too long.

 

I ground down the screw a bit with my dremel.

 

Here we can see the screw is now sunk in properly. This improved the left side selector lever immensely, especially between safe and semi. I suspect the problem with the feel going into full is more the fault of the selector plate. The right side lever is still mushy because the shaft's connection with the selector actuator isn't that great.

[staticzero]

From top, G&G Piston set, CA Piston set, UTG Piston set. Interestingly, the piston head appears to be a copy of a CA (though the holes aren't drilled out), not of a TM. You can see the indentations where the holes should be.

 

Top: UTG piston set, Bottom: G&G piston set

 

Top: UTG Spring, Bottom: CA M15A4 stock spring

 

Top: UTG Spring Guide, Bottom: Area 1000 Spring Guide

 

You can view the album here, if you'd like higher res photos.

 

So far I'm quite impressed with this gun. It shoots about ~250 out of the box, the hop up works well, the mags feed reliably as long as they're wound enough (I was able to drain a hicap almost completely start to finish on one full wind), and the battery is quite good. The body components are solid with a nice finish, the only weak point there being the quality of the sights.

 

The only real issues in stock form are the handguard pin being 'rough' and therefor hard to remove, and the selector lever not feeling so great. Both are easy to remedy. The compression isn't as good as it could be, so if you have the ability to fix that it would be a good idea, but it isn't necessary to use the gun. There's really nothing that will keep you from using the gun out of the box. Toss the 'sling' though, it's trash.

 

The weakest component, if you intend to install an upgraded spring, seems to be the motor. With a CA M15 stock spring installed, the gearbox easily gets locked up if the cycle is interrupted when the spring is fully compressed. It fires reliably on semi, as long as you let it complete the cycle every time. Even with my most powerful battery connected, it has a hard time turning over when locked up. Because the shimming isn't too tight, and the wiring appears to be good quality, and the battery is good, and the spring isn't all that heavy, it seems like the motor just doesn't have enough torque to do the job. I do need to collect some more data to be sure, however. There may yet be an alternate solution.

 

Also, I tested a TM lowcap, a CA hicap, and a Star realcap (bought a box of them for this gun). All fit and functioned flawlessly.

 

That's it for now. As always, if you have any questions, or want me to go into something in greater detail, ask away.

[staticzero]

That is awesome. I cant wait to get one. My next project gun!

 

*starts looking for pennies on the street*

 

<{POST_SNAPBACK}>

With how cheap it is, it won't take you a lot of looking.

 

 

When these guys release a cheapo MP5K, I have a new sidearm.

<{POST_SNAPBACK}>

You might not have long to wait, Peter at AEX told me they have something like 50 new products lined up. Their next AEG will be a TM AK-47 copy for those interested.

 

damn static... another great review  

 

I am worried more about the long term of the arc and utg guns.  I wanna wait a bit longer to see how things work after a few skirms and such before I drop any money on a full gun

<{POST_SNAPBACK}>

Thanks. I'm looking forward to finding out how it does over the long term as well. The gun will be getting a good workout this weekend, you can be sure I'll report any problems I encounter! Two of my friends each ordered one as well, and I'll be keeping my eye on them too.

 

Here are some pics of the flash hider that I forgot to include. You can see it threads in to the outer barrel which is not how the TM works as far as I know...

 

 

A CA or TM front sight should fit, and would allow for mounting of a compatible suppressor.

[Sledge]

Would you say this would make a good CQB weapon? At 250 fps, it's not gonna be a woodland choice, but could be a good cheap way to get into the sport.

 

[staticzero]

Would you say this would make a good CQB weapon? At 250 fps, it's not gonna be a woodland choice, but could be a good cheap way to get into the sport.

 

<{POST_SNAPBACK}>

Certainly! In fact that's what it's going to be used for this weekend. Of course there's no need to recite the merits of an MP5 for CQB work, I think this gun is a great choice (especially with the sliding stock fitted, note that it has three positons as well). And while it would be a great starter gun, I also think it would be handy as a second gun specifically for CQB, since it's so cheap. If for example the main site you attend has a high FPS limit (in my case, 400FPS), but there are CQB events or sites you also want to attend that have a lower limit (in my case 350FPS for the event this weekend) you could have a gun appropriate for each without breaking the bank or having to use a reducer (and therefor being limited to semi-only). It's also a good choice if you just want to have a loaner gun you don't need to worry about.

 

Another great review/analysis.

<{POST_SNAPBACK}>

Thanks!

[vengecore]

excellent post Static! i've been wanting to take mine apart but I'm afraid i couldn't get it back together. thanx for doing it for me. I'm getting a TM front sight so ill let evrey one know how it works.

 

TM 200rd Hi-cap works great in mine!

[Tunershark]

Wow , awsome.

 

i have one in the mail, along with a flashlight grip, cant wait

 

so i guess the only way to install the TM,Ics,CA flashhiders is to buy a new front end then?

[clmwrx]

looks like the same mechbox in the mp5kpdw

[staticzero]

Wow , awsome.

 

i have one in the mail, along with a flashlight grip, cant wait

 

so i guess the only way to install the TM,Ics,CA flashhiders is to buy a new front end then?

<{POST_SNAPBACK}>

Seems that way, yes.

 

Of course if you're skillful and have the tools and knowhow, you might be able to find another way though careful modification.

 

Aside from that, a driect fit isn't possible.

 

looks like the same mechbox in the mp5kpdw

<{POST_SNAPBACK}>

Naw. The TM MP5K is a v3 gearbox. This is V2.

 

Where did you order the flashlight grip from?

<{POST_SNAPBACK}>

Dunno about him, but I have a Guarder torch handguard on order from WGC, should arrive tomorrow. It's this one. I went with it since it didn't come with a light was therefor cheaper. I'm just going to use my Surefire G2 with it.

 

And now for some comparison pics! These are thanks to Airsoft Extreme who are very kind to put up with my shenanigans. UTG MP5 vs TM MP5:

 

Which is the TM? It should be obvious...

 

How about now?

 

And now?

 

This one is easy...

 

High res here.

[visionviper]

Nice, so how is the performance of the gun?

[vengecore]

is the TM shorter?

 

both guns look great! now just compare the internals.

[staticzero]

Nice, so how is the performance of the gun?

<{POST_SNAPBACK}>

Checkout Jordan74's review here for stock performance info.

 

With a stock CA M15 spring installed and the compression optimized, mine is shooting about 310 PFS. This puts it about on par with a CA MP5 as far as FPS goes. I've not tested range or accuracy yet. It feeds and fires reliably. The problem I'm having at the moment is getting the motor to push the heavier spring. I'm still working on it.

 

is the TM shorter?

 

both guns look great! now just compare the internals.

<{POST_SNAPBACK}>

Nope, same size. The angle of the photo might be tricking you...

 

I don't think I'll be able to compare the TM internals any time soon, not having access to a gun I can dismantle.

[DCF]

Very nice review. Kudos to you.

 

Some more questions for you:

 

1. Have you try to install metal bushing yet? I hope it fits.

 

2. How difficult do you think to rewire the battery to the back and opening up space in the buttstock in order to fit a battery?

 

3. Do you think a break in to the motor would help? Or a new motor is necessary to power a M100 and up spring?

Break in the motor: http://www.rccaraction.com/rc/articles/sup...rge_stocker.asp

[staticzero]

Very nice review. Kudos to you.

 

Some more questions for you:

 

1. Have you try to install metal bushing yet? I hope it fits.

 

2. How difficult do you think to rewire the battery to the back and opening up space in the buttstock in order to fit a battery?

 

3. Do you think a break in to the motor would help? Or a new motor is necessary to power a M100 and up spring?

Break in the motor: http://www.rccaraction.com/rc/articles/sup...rge_stocker.asp

<{POST_SNAPBACK}>

1. No not yet. I should have checked the size of the stock ones with my calipers, I'll try to remember to do that next time I have the box apart.

 

2. Not difficult. No need to make room in the stock, it's designed for a battery already. Just remove the weight that's in there first (it comes right out). There's already a large tamiya connector coming out of the gearbox in back, it connects to an extension that goes to the front. Either buy or build a new extension for the stock (and route it properly), or reroute the existing one (keep in mind the existing extension ends in a mini tamiya). Note the stock will only fit a large type 8.4v battery, a 9.6v pack is too long. Perhaps modification to make more is possible? I couldn't say, I'm new to MP5s.

 

3. GOOD NEWS on this front. Short version: the gun works great after changing out the stock extension cable and connectors better quality parts. With the stock CA M15 spring and the included 8.4v 1100mAh NiMH battery the gun now shoots about 310 FPS and has a ROF of about 700 rounds per minute (100 less than realsteel). It hasn't locked up since, even when I try to do it deliberately.

 

Longer version: I decided to try and fix the lock-up issue by starting from the cheapest solution and then moving up the line from there. I sort of skipped ahead a bit but not by much. I should have swapped just the wire first, but that would have been a waste for me. See, I use deans connectors in all my AEGs, and I needed to convert this one anyway. I wanted to use 16 AWG wire, however I didn't have enough left, so I used 14. 14 won't work in the gearbox so I left that as-is, and it proved to be a little tight in the body though it did work. However, it has caused the seam at the top of the gun where the two body halves meet to bow out a tiny bit. I don't recommend 14 for this reason, 16 would be the best choice and I'll switch to it in the future. I also switched all the connectors to deans and removed the fuse from the equation (not generally recommended unless you know what you're getting yourself into).

 

So basically, I changed the connector on the wire coming right out of the gearbox to a male deans, made a new extension to go to the front out of high quality 14AWG wire with a male deans on one end and a female on the other, and changed the included battery's connector to a female deans. After reassembling everything, I tested it by firing bursts of full auto, and incomplete shots on semi. Despite parking the spring at the fully compressed state several times, the gun always fired on the next pull of the trigger. Sweet!

 

Total cost? 18" of wire at $1/foot = $1.50, 2 sets of deans connectors = 2 x $3.25 = $6.50. Plus tax, that's still under nine bucks. Cheaper, if you don't need the flexibility the extra intermediate connector in the rear affords. Just skip the second set of connectors and solder the new extension right to the gearbox wire and save yourself $3.25.

 

I'm still going to go back and redo the extension with 16 gauge, and replace the wire inside the gearbox with the same, once I get some more wire. Hopefully that will improve things even more.

 

Bottom line, the motor is fine. Replace the extension wire (at least) and you should be able to run a 1J spring, even with the included mini battery.

[slayer544]

so i guess a hurricane kit is out of the question?

[ef9]

staticzero: how do i know if my hop up is off or on? i mean when it came out of the box i just stuck the cleaning rod down the barrel before i shot it and now i dont know if i damaged the hop up or not... how can i check it since i know it can cause some irreversible damage to the gun...

 

thanks a lot

[lacroixpamplemousse]

Hey, would you mind making a tutorial on the wiring stuff? I have experience soldering, so thats not a problem, but I'm a total newb to the airsoft stuff. Even just a few pictures of where to solder and junk. Mine isnt having any real problems, but anything I can do for cheap to make it perform better makes me happy.

 

Also, how do i edit the hopup? My hopup makes it shoot about 10 feet above where I aim if its on...

[nynja]

Excellent review - by far the best and most technically complete review I've read about the UTG mp5.

 

 

After having yours apart - what in your estimation would be required (upgrade wise) to get this firing 325~350fps with a rate of fire around 800/pm? I have one of these on order (should be here today yay!) and my goal is to turn it into a CQB weapon. That being said it's also going to be my toy for learning the internals of an AEG - so I want to play with some internal upgrades. I'd love to get this thing setup to push .20g bb's about 325fps with a nice rate of fire.

[staticzero]

First, a quick revision to what I said previously. You actually need two 18" lengths of wire, one positive and one negative. Little bit of a brain fart on my part I guess...

 

Also, please note that I've not conclusively proven which part made the difference. It could be that just changing the wire would be enough, or perhaps all you need to do is change to better quality tamiya connectors, or perhaps I could have left the wiring the same and simply changed to deans. I don't have the date to say for sure.

 

After I change the wiring in the gearbox, if the ROF increases, we'll know that the wiring change does make a difference. I know the deans connectors usually do, that's why I use them in all my AEGs (and it's partially thanks to them that I can run a way-over-the-limt spring in it on a 7.2v battery in my M15).

 

Regardless, changing out all the wiring and connectors is fairly inexpensive, and makes for a significant improvement. It's totally worth doing in my book.

 

so i guess a hurricane kit is out of the question?

<{POST_SNAPBACK}>

No, it's certainly not out of the question. However I feel that any level of spring upgrade is going to require that you optimize the wiring.

 

Hurricane makes three kits for the MP5 that I know about, one of which is definitely over forum limits so I won't discuss it here. You should be able to run the M90 and M100 versions of the kit after you improve the wiring, but even at this power level I suspect you might want to run a 9.6v battery.

 

I think it's kind of a waste though, there's no real need to replace the cylinder, cylinder head, or nozzle. For a 1J upgrade I think the metal bushings are unneeded as well, though they aren't a bad idea. All you really need is a better o-ring for the stock piston, and a 1J spring. A bering spring guide probably isn't a terrible idea though.

 

staticzero: how do i know if my hop up is off or on? i mean when it came out of the box i just stuck the cleaning rod down the barrel before i shot it and now i dont know if i damaged the hop up or not... how can i check it since i know it can cause some irreversible damage to the gun...

 

thanks a lot

<{POST_SNAPBACK}>

There's no on or off really, it's all one big grey area. You know it's on all the way if the BBs go out a ways and then fly straight up...

 

Adjusting it is simple. There's a small lever on the left side of the gun same as most MP5s. Pushing forward increases hop, pushing it back decreases it.

 

Refer to the pic here if you don't know where the adjustment lever is:

http://www.arniesairsoft.co.uk/reviews/ics...-hopuplever.jpg

 

Hey, would you mind making a tutorial on the wiring stuff? I have experience soldering, so thats not a problem, but I'm a total newb to the airsoft stuff. Even just a few pictures of where to solder and junk. Mine isnt having any real problems, but anything I can do for cheap to make it perform better makes me happy.

 

Also, how do i edit the hopup? My hopup makes it shoot about 10 feet above where I aim if its on...

<{POST_SNAPBACK}>

See my above statements regarding the hop up adjustment.

 

As for the wiring, have a look at this pic:

See the long wire that's laying part way on the body, with white tape on it? It's right square in the middle of the pic so I hope so. That't what I replaced.

 

If you know how to solder its a simple procedure. Just get two 18" pieces of 16AWG high silicone wire and solder connectors to each end. The other connector I changed, besides the one on the battery, was the one on the wire coming out the back of the gearbox (you can see it in the pic as well). Just cut off the old connector and solder on a new one.

 

If you need a guide to taking apart the gun to do this, well I'm not going to be able to get into all that at the moment. I'm sure there are plenty out there already though, just look for a TM or CA MP5 take apart guide.

 

If you want to replace the wire in the gearbox, that's more complicated. However, if you can take apart a gearbox I think you'll be able to figure it out. Otherwise, wait for me to replace the wire in mine, I'll be taking pictures of the process.

 

I would absolutley LOVE to see their future product line up!

I don's anybody is in the position, or know anyone in the position, to send them a review of their gun... if they know any future problems (that dont cost them to fix) they will change it... however you would need a decent contact!

<{POST_SNAPBACK}>

Thats a good idea, if they just improved the quality of the wire, I think they could avoid a rep for having weak motors. Using a better o-ring on the piston head would be advisable as well.

 

Excellent review - by far the best and most technically complete review I've read about the UTG mp5.

After having yours apart - what in your estimation would be required (upgrade wise) to get this firing 325~350fps with a rate of fire around 800/pm?  I have one of these on order (should be here today yay!) and my goal is to turn it into a CQB weapon.  That being said it's also going to be my toy for learning the internals of an AEG - so I want to play with some internal upgrades.  I'd love to get this thing setup to push .25g bb's about 325fps with a nice rate of fire.

<{POST_SNAPBACK}>

Thanks. Unfortunately as Shao has stated, I can't get into that here. Besides, I wouldn't be able to do anything but speculate at this point, anyway.

[staticzero]

325 with .20g should be easy. M100 or similar, better cylinder head o-ring, optimized wiring.

 

However, an M100 may be too hot. something like a PDI 120%, or even an M90 or Systema 1J spring might be a better choice. M100's can be at or over 1J depending on the application.

 

Keep in mind that the general long-term durability, and the ability of this gun to survive an upgraded spring, remains to be seen. It's possible it will be fine, but it's also possible mine is going to explode tomorrow. It's just too soon to tell.

 

Oh, and welcome to Arnies!

[nynja]

325 with .20g should be easy. M100 or similar, better cylinder head o-ring, optimized wiring.

 

However, an M100 may be too hot. something like a PDI 120%, or even an M90 or Systema 1J spring might be a better choice. M100's can be at or over 1J depending on the application.

 

Keep in mind that the general long-term durability, and the ability of this gun to survive an upgraded spring, remains to be seen. It's possible it will be fine, but it's also possible mine is going to explode tomorrow. It's just too soon to tell.

 

Oh, and welcome to Arnies!

<{POST_SNAPBACK}>

 

lol. Well lets hope that it manages to stay together.

 

I got in on the buy while they were 79.95 from AA - my thought was simply "hey - for 79.95 how can I go wrong?" Also, as stated, I'll be using it as an experiment to get comfortable messing around in the mechbox and again for 79.95 how can you go wrong. Even if you toss an upgraded spring/wiring and o-ring (all relatively low cost upgrades) and it runs great for 6 months - and then you have to toss another 100 or so at it for new gears and what not.. you're still far ahead of where you would have been with a Marui. At least - that's how I look at it.

 

Thanks again for the review and the welcome!

[staticzero]

I think that's a great perspective, and it's just another example of how this gun is a great tool for people new to AEGs, or airsoft in general.

[bignaz]

Hey static nice review. I ordered mine tuesday and shorty hasent sent it out "******s" so im hopeing to have it by monday or maybe tuesday if not they better send alot of free stuff or im gonna be uber p'ed off.

 

 

question is what piston would you recamend or what pistion head? What do you think the first upgrades should be as far as piston ect.

 

 

PS i plan on upgradeing my wire with the high qualty stuff from my rc days lol. "i like how its like a wet noodle lol" Im thinking powerpoll instead of deans tho. i never really been a big fan of deans. Thanks for your input no rush on a awnser its gonna be awhile before i get this becouse shorty usa is takeing there sweet time but im glad i seen your tut before i got it so i can fix the switch and rewire it and fix those 2 problems before i use it.