UTG MP5 AEG Dissected! Quite impressive really...

[lacroixpamplemousse]

I like the gun, dont like the mags. Its been doing some weird blank shots lately... Im probably just going to order a box of star mags. Btw, has anyone ever tried clamping 2 mags together and sticking the battery in the second mag? Kuz then i could use full time retractable stock and still use my special frount grip.

I looked at it last night, and it looks like it should barely fit inside a lowcap normal size mag (It might have to have a little less curve or be about 1cm wider).

[ef9]

I did a bit of googling around, I wasn't able to find anything. If they do have one, it's probably under the .CN TLD, but again, haven't been able to locate anything.

 

And just to add my .02 cents here, I recently obtained one, as well as a friend of mine. He used his at a skirmish last weekend, and we had zero problems with it. Chrono'ed at 275 fps using .20s. Range was about on par with a stock Tokyo Marui.

 

If these hold up, I think UTG is going to have a big market.

<{POST_SNAPBACK}>

 

 

how did u get 270fps?...mine was only doing max of 255fps consistent tho..... but as i took more shots the fps goes down... weird

[mightyjebus]

excellent review..so good infact I have just ordered one to be sent to me in the Uk.

if any UK people are wondering about the price it cost $160.96 shipped to the Uk which is £88.23 at todays exchange rate. www.shortyusa.com

I have a couple of questions ref the MP5 ... can someone post a picture showing the difference between the UTG and TM front end. especially the screw thread that attaches the flash eliminator.

some people have mentioned feeding problems in the above posts ..is it only with the supplied magazines or do all types of magazines have feeding issues?

[bignaz]

i dont know if its people new to high caps only haveing probs but me and static havent had any feed problems with out stock high caps.

 

oil+good bb's= no probs

 

case your woundering im useing silacone oil fulling winding the mag and shooting ksc's

 

i tested some elcheepo's not really cheep they were from meijer so there $$$$ but cheep qualty lol it said premium so i thought i would try out the .20 flying colors. no jams but out of the 2,000 rounds a had a few miss feeds but nothing to keep me from useing them as a last resort bb if i cant get ahold of any deacent ones.

[staticzero]

Okay, since some people seem to be having some issues with the included hicaps, I thought I'd better look into them a bit.

 

Lets take a moment to examine the mag's design, and in doing so try to understand how it works. Picture time! (This will be multiple posts because of the ten-pic-per-post limit)

 

Front

 

Side

 

Back

 

Top, Closed

 

Top, Open

 

Bottom

 

Mag clamp removed

 

Bottom plates removed

 

The internal mechanism

 

The internal mechanism. Note the placement of the small silver nut.

[staticzero]

The internal mechanism again

 

Generally I'd stop here as far as disassembling the mag body goes. There's really nothing to gained by taking the rest of the shell apart. Don't do it. You could break it, or lose parts. I did it for the sake of showing you that you don't need to ever do it.

 

You have to start by removing the screw from under the fake bullet door. That will let you remove half of that 'mag'. Next you have to split the other half of the bullet door side from the feed tube side by prying this clip out. Small metal nuts will be falling out from time to time, keep your eyes peeled.

 

With the clip disconnected, the remaining half of the bullet side can be separated from the feed tube side. You then remove the screw in the side of the feed tube 'mag', allowing it to split.

 

The feed tube side split, BB stop and spring shown.

 

The mag body fully disassembled. Note the placement of all three of the metal nuts in the sides of the mag body.

 

The internals

 

The internals

 

Note the dimples on this wheel, if you can make them out. It's the job of this wheel to agitate the BBs to keep them feeding properly.

 

Here is the internal mechanism as viewed from the top. BBs funnel into the area on top of the white paddle wheel and get pushed up the feed tube.

 

Here is the internal mechanism split into it's two halves. You need to remove four screws to do this. You can see the track the BBs follow as the get pushed in and down and around and then up the feed tube. Also take note of the detent wheel and spring on the left, it prevents jamming by making sure the BBs flow into the mechanism one at a time. The other end of the spring interacts with the winding wheel, preventing it from spinning backwards. It's what produces the usual clicking sound as you wind the mag.

[staticzero]

Here is the paddle wheel opened up. You can see the spring. It is fully unwound in this picture. You can also see the indentations on the inside of the wheel where the folded end of the spring sits. When the spring is fully wound, the end slips from notch to notch producing the 'clack' sound when the mag is fully wound.

 

Here I've partially wound the spring.

 

The album containing the above pictures, as well as larger versions of them, can be found here.

 

I've found the mag can hold about 250 BBs. I filled one of mine up completely, dumped it, and counted by hand. The result was 254. With this in mind be sure that you fill the hicap from both sides in order to fit the most BBs in. To fill the hicap to its maximum potential:

 

1. Open up either door and put in some BBs.

2. Wind the hicap enough to force BBs all the way up the feed tube and then stop.

3. Add more BBs, shaking and rattling the mag from side to side as you go. This will even out the BBs as much as possible.

4. At some point the side you're putting BBs in will start to fill up. Switch to adding BBs to the other side. Don't forget to shake the mag from time to time. Repeat this process until both sides are full. You'll need to put the last bit in by hand rather than pouring them in, and you may want to gently press down to force in as many as possible. Take it easy though, don't over do it.

5. Wind the hicap completely. It takes a while. The sound will change when it's wound all the way. Don't worry about over-winding, you can't. When you think it's wound, keep winding to make sure the sound stays 'changed'. I've noticed they can occasionally throw out the other sound once in a while while winding, even though it isn't wound completely.

 

Having fully loaded and wound the mag, I inserted it into my gun. I fired off a few shots in semi, then a burst of auto, some more semi, a steady stream of auto, and then bursts of auto until the first time I heard a miss-fire (blank). I then removed the mag, opened it and shook while upside down it to see how many BBs would fall out. None did. I then examined the feed tube, there were still BBs in it as expected. I held open the BB stop with my fingernail and let the remaining BBs fall out. I counted them and found 14 remained.

 

What this means is that the mag was able to feed about 240 rounds without needing to be wound. That there were BBs remaining in the tube it typical of all hicaps (excluding the P90's). There were no miss-feeds until the mag was depleted.

 

Note that this was only one of my mags, and it was only tested in this way this one time. It's hardly conclusive. However, I urge anyone that is having miss-feed issue to make absolutely certain that they are winding the mag all the way.

 

It would probably be a good idea to not cram every last BB you can into the mag, they need a little room to shift about in order to feed into the mechanism properly. You also might want to wind the mag as you go when you have a chance, the more tension on the spring the less likely the mag will miss-feed. Also, use good quality BBs, inconsistencies in BB size and shape can lead to all sorts of problems. Finally, it might help to lubricate the axles of the gears in the hicap to make sure the spin smoothly.

 

 

 

Now I'd like to take a moment if I may to welcome all the new people to the forum this thread seems to be attracting. It's great that your interested in this gun and my work on it. I would also like to ask as Shao has already, that before you post, please do read the forum rules.

 

Also, please do your best to keep this thread on topic. It's my goal here to objectively assess and discuss the design, build, and function of the gun's internals, to report successes and failures while trying to improve the gun, and to a degree examine potential parts compatibility issues. It's also my intention to do this with cost-effectiveness in mind. If you'd like to discuss UTG's future spring MP5 or AK AEG, checkout this thread in the news forum. If you're interested in this gun's stock performance, there's a great review in the reader's reviews section by Jordan74. If there's anything else you'd like to discuss off topic, such as the geopolitical ramifications of this product, or wether the gun will cause marui to go bankrupt, or whatever, well there's a whole bunch of forums here for you to start a new thread in.

 

I'd also like to keep the discussion to actual observations or inference based on actual observations. Speculation not grounded in fact can be dangerous. Please be careful when making claims based on something someone said somewhere else, or something you heard from someone, or this guy in a dark alley totally said this, etc. I appreciate everyone's desire to contribute and I want to encourage you to do so, however the most useful information comes from first-hand experience and observation. Please keep this in mind.

 

I also request that you read the whole thread before you reply or PM me with questions, a lot has been covered and your question may have been answered already. I'm more than happy to answer your questions if I can, but having to answer the same ones can be a bit demoralizing. If you can't take the time to read the whole thread, I'm not sure I can take the time to reply to you, if you follow my meaning. Incidentally I'm thinking writing up a FAQ for this gun may be in order, so if you do have some original questions or concerns that you think should be included, please ask away.

 

And finally, don't be afraid to investigate issues you encounter yourselves! If, say the mag isn't working for you, try to understand the issue if you can. Don't just set the thing aside and use a different mag, investigate how it should work and see if it is working as you expect. In doing so you can learn quite a bit, and in turn give back that knowledge to others.

 

I like the gun, dont like the mags. Its been doing some weird blank shots lately... Im probably just going to order a box of star mags. Btw, has anyone ever tried clamping 2 mags together and sticking the battery in the second mag? Kuz then i could use full time retractable stock and still use my special frount grip.

I looked at it last night, and it looks like it should barely fit inside a lowcap normal size mag (It might have to have a little less curve or be about 1cm wider).

<{POST_SNAPBACK}>

Why doesn't the included battery fit in your handguard? What kind of handguard is it?

 

how did u get 270fps?...mine was only doing max of 255fps consistent tho..... but as i took more shots the fps goes down... weird

<{POST_SNAPBACK}>

It could be that his compression is better than yours. Having proper compression can make a huge difference. In my upgraded M15, fixing the compression resulted in an increase of about 80 FPS (putting me over my field limit by 30FPS actually, I still need to fix that). In the case of a stock UTG MP5, I could see it making a difference of as much as 30, but perhaps more on the order of 15-20. This is just speculation you understand, I'd really like to see what happens when someone improves the compression without changing the spring or other internal components too (like I did).

 

excellent review..so good infact I have just ordered one to be sent to me in the Uk.

if any UK people are wondering about the price it cost $160.96 shipped to the Uk which is £88.23 at todays exchange rate. www.shortyusa.com

I have a couple of questions ref the MP5 ... can someone post a picture showing the difference between the UTG and TM front end. especially the screw thread that attaches the flash eliminator.

some people have mentioned feeding problems in the above posts ..is it only with the supplied magazines or do all types of magazines have feeding issues?

<{POST_SNAPBACK}>

I posted some pics of the UTG's muzzle removed already, and you can look up pics of TM/CA/ICS muzzles on stores and other sites to compare to if you like. I will be examining this topic further though.

 

People have reported feeding problems with other hicaps besides the included ones. I don't think anyone has reported problems with standards. My gun feeds reliably with the included hicaps as long as they are wound properly, and I have tested Star lowcaps, a CA hicap, and a TM lowcap as well. I saw no issues with any of them.

 

Still to come: Guide to rewiring the gun, M100 upgrade, front sight and muzzle compatibility, maybe more (who knows!). Stay tuned!

[malkav33]

does anyone know the size/dimensions on the screw that goes into the fire selector (the very tiny one) and the one that goes into the mag release button on the right side (also somewhat small)? i've been to two or three different places trying out screws and haven't been able to find screws small enough. the reason i'm asking is because both of mine were stripped when i got 'em (even using precision screw drivers could barely budge them, i had to actually carve grooves into one of the screws to get it out)

 

edit: actually, those two screws (one that goes into fire selector and one that goes into mag release button) are the same. i think i didn't notice it before because my mag release screw is so mutilated

[Tunershark]

got mine today, posted pics in the mp5 pictures thread. i never realized how metalish the plastic looks on this gun, when i opened this up i could have swore it was all metal. and the mags are ok i guess but they dont fit so nicely into the mag well, they make an odd clicky sound when they get bumped but my STAR mag fits well into there, i havent had a chance to shoot mine yet(battery still charging) but this gun feels pretty nice

[Shao14]

Thread cleaned up a bit. As Staticzero said above,

 

Please keep your posts in this thread on the topic of the technical aspects of the UTG MP5, and state facts, not speculations or guesses.

 

To new members, please read the general forum rules http://www.arniesairsoft.co.uk/forums/inde...p?showtopic=386 before post. In particular, do not discussion guns above 1j energy limit (i.e. 328 fps with .2g BBs)

 

Lastly, read what have been said before asking a question, so you don't ask the same question that's' been answered on an earlier page.

 

Cheers.

[slayer544]

ok so I got bored one day and ordered some upgrades. I got metal bushings, a spring guide w/ bearings, and a spring that is over the forum limit so I wont talk about it . but yeah, I'll most likely install that stuff and rewire everything and see how it goes(hopefully not trash my gun) and probably post vids and pics on airsoftretreat.com.

[lacroixpamplemousse]

Nah im getting a new foregrip which doesnt have room for a battery, just throwing out some other ideas that could work.

[Shao14]

An update from me:

 

I lube the mags a bit, manually wind and un-wind them a couple time, and did some more tests. On one full wind of the mag, the spring tension is more than enough to empty the full hi cap, and after a few tests, the feeding issue became less serious, and in fact, one of the hi caps now feeds fairly reliably on both semi and full auto. The other still skips a bit, and when that happens, I just shake the gun a bit and/or switch fire mode, and it'll continue to feed without needing re-wind, and it'll empty the whole mag in one winding regardless of skipping or not.

 

I charged the stock battery with the stock charger for 4 hours (1100 mah with 300 ma charger). Battery seems to support around 1000 shots (I really didn't count, but it was like 5 or 6 hi caps with lots of blank misfeeds, and I did not shoot it all at once, it was over 4 days period.) before it ran dry.

 

Now, a new problem, the fire mode selector switch just fell off. Mine doesn't have that problem Staticzero had (which he described on the first page), but mine doesn't stay on the gun securely. The problem is the screw (shown in picture) that's supposed to secure the switch on to the fire selector shaft does not go in long enough. I'll have to find a longer screw, or just a new fire selector.

[ef9]

great post static zero , would like to see the upgrades on it like m100 springs , motors , pistons.....

 

btw did u replace the o-ring that u said the stock was kinda shoddy?

[lacroixpamplemousse]

An update from me:

 

I lube the mags a bit, manually wind and un-wind them a couple time, and did some more tests.  On one full wind of the mag, the spring tension is more than enough to empty the full hi cap, and after a few tests, the feeding issue became less serious, and in fact, one of the hi caps now feeds fairly reliably on both semi and full auto.  The other still skips a bit, and when that happens, I just shake the gun a bit and/or switch fire mode, and it'll continue to feed without needing re-wind, and it'll empty the whole mag in one winding regardless of skipping or not.

 

I charged the stock battery with the stock charger for 4 hours (1100 mah with 300 ma charger).  Battery seems to support around 1000 shots (I really didn't count, but it was like 5 or 6 hi caps with lots of blank misfeeds, and I did not shoot it all at once, it was over 4 days period.) before it ran dry.

 

Now, a new problem, the fire mode selector switch just fell off.  Mine doesn't have that problem Staticzero had (which he described on the first page), but mine doesn't stay on the gun securely.  The problem is the screw (shown in picture) that's supposed to secure the switch on to the fire selector shaft does not go in long enough.  I'll have to find a longer screw, or just a new fire selector.

<{POST_SNAPBACK}>

 

If I were you id buy a new assembly, I dont like the screws taht come stock in this thing, and that part was the one of the major parts i dont like (screw wise that is).

[1Bean1]

Those fake bullets on the top of the UTG high caps can be removed also, while still retaining the sliding plastic tray (it was a personal thing, I didn't like the way they looked). 2 screws is all.

 

 

 

Duct tape on the inside-side of the connecting mag of the high-cap can help minimize magazine wobble. (Yes, it's an old airsoft trick, but others might not be aware of it.)

 

 

 

Side Note: On the high cap, one of the metal clamps is held by a screw that requires an hex/allen wrench to remove it (preferably the use of a hex wrench with the rounded end). Removing the clamps and other 'cosmetics' on the high caps really lightens their weight, which I prefer over the looks of it.

[Shao14]

Couple other things I forgot to mention:

 

The hop up on mine does not stay in place, and as I shoot, it moves to the forward position.

 

The scope mount's spacing between cuts are not the same as the standard weaver rails'.

[staticzero]

Nah im getting a new foregrip which doesnt have room for a battery, just throwing out some other ideas that could work.

<{POST_SNAPBACK}>

Yeah, but which one?

 

Now, a new problem, the fire mode selector switch just fell off.  Mine doesn't have that problem Staticzero had (which he described on the first page), but mine doesn't stay on the gun securely.  The problem is the screw (shown in picture) that's supposed to secure the switch on to the fire selector shaft does not go in long enough.  I'll have to find a longer screw, or just a new fire selector.

http://i5.photobucket.com/albums/y171/shao...ireselector.jpg

<{POST_SNAPBACK}>

Interesting. Given malkav33 and your problems with the screw, perhaps I'll try to figure out the size/therad patter so people can get replacements.

 

great post static zero , would like to see the upgrades on it like m100 springs , motors , pistons.....

 

btw did u replace the o-ring that u said the stock was kinda shoddy?

<{POST_SNAPBACK}>

Actually, I replaced the whole piston/piton head set with a spare G&G set I had laying around.

 

The hop up on mine does not stay in place, and as I shoot, it moves to the forward position.

<{POST_SNAPBACK}>

You could replace the o-ring that holds the lever in place with one of the same thickness but a smaller inner diameter, or perhaps just a slightly thicker one. That should prevent the lever from moving. Otherwise, you could try shimming either side with a washer.

[frontplayer15]

I know that some people were having problems with the mags so i found a soluttion for you. If you have low cap mags with 30 shots. And hate having to wind high the high caps then this is perfect for you. 8 90 round mags for $45. http://cgi.ebay.com/MAG-MP5-Mid-Cap-90-Rou...1QQcmdZViewItem

[gti_vw]

Just thought i would throw in my accuracy test using stock UTG Mp5 at 50 ft. Semi auto. Beware i am not a very good shot !My Webpage

[TjM2147]

Hey static i am now close to buying an UTG MP5 from Airsoft atlanta and you can say im somewhat of a newb when it comes to AEGS(internally anyway) i wanted to ask you what would be the best way to uprgrade it to at least 300 fps??

[staticzero]

Right now all I can say for sure is that you'll want to do the following:

 

1. Change out the wiring (at least the extension) and connectors to lower resistance stuff (After changing to a 14AWG extension and deans connectors in my case so far, I could run a stock CA spring good for ~315FPS. Not before).

 

2. Buy a spring that should get you to the FPS you want, I'm not really sure what's good for 300 FPS. Maybe a Systema 1J or similar?

 

3. Ideally, replace the piston head or just the o-ring, or otherwise somehow improve the compression of the cylinder set, if your gun needs it. Mine did. Anyone else get to check theirs yet, incidentally?

 

Oh by the way, my order arrived:

 

 

 

It's not all for me, some of it is for a friend's UTG MP5. Anyway, its going in this weekend so I'll have a bunch of stuff for you guys soon.

[TjM2147]

so should i jus buy a hurricane kit for the mp5 that comes with an M120 spring a poly piston head and a bunch of other stuff?

[TjM2147]

so should i jus buy a hurricane kit for the mp5 that comes with an MXXX spring a poly piston head and a bunch of other stuff?

 

Edited by shao14: no discussion on high power springs please.

[staticzero]

Please read the rules (And the thread, we've been over this)! We can't discuss upgrades over 1 joule (about 328FPS with .2g BBs) on this forum. That means no spring over M100. Also try to avoid double-posting

 

Furthermore there's still no data (yet) to show that the stock motor will be able to drive even an M100, even with upgraded wiring. Plus, a kit like that, even if it comes with an M100 or less, is going to leave you with parts you don't need. It may not be the best move financially speaking.