FPBBrandon Posted December 20, 2005 Report Share Posted December 20, 2005 To 56k-ers: WARNING- This thread has 'enough' pictures. Turn back now, or your computer may explode. Well with the wide proliferation of this thing, and mine being broken (busted spring guide), I thought it would be a great time to write a technical article. First of all, its pretty rudimentary, but it may help some of the first timers out there who own this if their time to own a busted gun comes. Secondly (and possibly most importantly), just because this guide says how to take your M87 down, that DOES NOT mean you should. If the gun is working, you take it down, and break something, that is your own fault for being dumb enough to open a perfectly working gun. Shame on you and your family, and if I get a single PM about anything of the like, you will be publicly stoned. Disclaimers aside, lets start ripping this thing apart. My gun's version is the M87 SOS, and has a collapsable stock/pistolgrip. Some steps may differ among models in terms of prying off aesthetic bits and bobs. Directions: Step 1: Remove the two side rails with a phillips screwdriver. It may seem unnecessary, but these screws actually go into the guns reciever. To remove the RAS unit, these have got to go (on both sides). Remove the two screws holding each panel in, and for god's sake, keep the screws and panels together. Step 2: Now you have some rails removed from the side of your gun. Woo! Actually, now its time to remove the RAS saddle from your reciever, by removing the two small phillips screws on the bottom of the RAS itself (on both sides). Set this part aside with the rails, and again keep the screws together. Step 3: So you've just removed some aesthetic parts. Congratulations, you can use a screwdriver. If you have been confused up to this point, turn back now. Now, You must remove the stock, by pulling down on the adjustment lever on the bottom. I know on my first M4, it stumped the *fruitcage* out of me, so this may or may not be a useful step. Step 4: Time to remove the buffer tube! Again, a rather simple step. One screw, as pictured below, on the side of the tube holds the whole set on. Remove this screw, and as youre removing the buffer tube be careful, as it contains both an Iron bar, and a retaining spring. Make sure not to lose these, and set this assembly aside, with the retaining screw. Step 5: So now, if you've done well, you should have this crazy looking pistol-grip shotty. If not, die. Now that you've made it all cool with no stock, lets fix that by removing the pistol grip too. Start with removing the two screws that were under the buffer tube before it came off (as blocked by my fonger in the picture below). Then move on to the two screws in the upper grip on both sides, and the three in the lower grip (only on the lefthand side). Be sure to keep all the screws some place you can remember which exact screw went where, as there are 3 different lengths of screws which come out of this grip. Link to post Share on other sites
FPBBrandon Posted December 20, 2005 Author Report Share Posted December 20, 2005 Step 6: The final step before we pry the damn thing off. Remove the weaver rail mounted on top of the grip. Again, 2 screws, very simple, dont lose them. Step 7: So holy ######! We've finally removed all the screws necessary to pry the grip off. Well what are you waiting for? Use a fine flathead screwdriver, and seperate the halves of the grip bit by bit. Work your way around the entire grip until the thing is loose enough to pull off. Step 8: Theyre off! Note Iron weight #2 in the grip. As bender would say... "Neat" Step 9: Now you have this crazy thing that looks like you could sling it under an M16 and feel perfectly normal (which I may well do one of these days). Direct your attention to the rear end of the gun where you will find a very large retaining hex screw, remove it and set aside. Step 10: Ok, The fun part. We get to start taking non-aesthetics apart. Start with the pump-guide rod. Just twist this counterclockwise by the frontpiece, and it will screw off of the reciever, and simply pull out. Note Iron bar #3 and retaining spring, and please dont lose them. Step 11: Now your gun is starting to look more and more like a pile of parts... Brilliant! Remove the outer barrel by simply yanking it off the front, its no longer retained by the pump guide rod. Be sure to note the body screw under the outer barrel for the next step Link to post Share on other sites
FPBBrandon Posted December 20, 2005 Author Report Share Posted December 20, 2005 Step 12: Spend some quality time with your reciever, removing every single body screw. Sound boring? You bet ya... MAKE SURE you get the screws next to the QC label, and under the outer barrel. Step 13: So holy ######. All is done, and its time to split the damn reciever open. I dont have a picture for this one but Ill explain it as best I can. Make sure the gun is hopup adjuster-side-up, and Slide a very small screwdriver between the plastic to pry it open, and as you do, you will notice the spring bucking upwards with some chunks of white plastic. Put your screwdriver on top of the white plastic blobs (technically the piston and cylinder) to keep them from shooting everywhere. Go ahead and lift the cover off, and disengage the spring by removing the spring guide from its locked position (to avoid rocketing parts across the room). If you do this right enough (and by right I mean carefully), all the parts should stay in place in the lower half of the reciever, and you wont have to go look for flying parts. This is what a UTG shotgun internally should look like prior to reassembly, save for the hopup (which was having it's bucking replaced at the time of the photo. So there you have it, a full down to the guts disassembly guide for the M87SOS. I applaud your stamina if you read this far. Hope it helped. Stay tuned for hilarious permutations I have planned for this thing down the road (M120 in a little springer anyone?) Link to post Share on other sites
Jason-Alaska Posted December 23, 2005 Report Share Posted December 23, 2005 Great write up! Thanks for taking the time to post it! Link to post Share on other sites
DanHS Posted December 23, 2005 Report Share Posted December 23, 2005 Neat Anyways, nice writup. I was thinking about a mildly stronger spring in an 870, but I thought the cylinder might crack. How thick is the cylinder? Do you think an AEG cylinder could be adapted and fitted in it's place or no? Looks like the 870 cylinder is longer and narrower. Prolly too much effort to try that anyway. Let us know what happens. Your comment on using it as an under-barrel mounted weapon is giving me ideas on buying another and doing the same... Link to post Share on other sites
Redeye Posted January 17, 2006 Report Share Posted January 17, 2006 Any luck putting a different spring in yet? Link to post Share on other sites
powelly Posted January 17, 2006 Report Share Posted January 17, 2006 i was also thinking of buying a utg shotgun and putting it under my M16A2. Link to post Share on other sites
FPBBrandon Posted January 17, 2006 Author Report Share Posted January 17, 2006 I apologize, I totally forgot I had posted this. Yes, I have replaced the spring with an M100, and (being very gentle with the shotgun) have had a very successful FPS increase, that is not really speakable on these boards. But make sure you keep the inside of the cylinder very very clean/silicon'ed as it helps the compression stay uniform, as I noticed the piston head on my particular shotgun was rather rough around the edges. There were multiple large regions missing from the edges of the piston head that would cause a noticeable decrease in combustion, so I filled them with acryllic latex caulk, which remains very supple even when dry. These two huge improvements have put the gun at an obscene fps for costing 35$, but if you do this, be very careful, as the spring guide of this gun is not a strongpoint, I reinforced my new one with some rather strong epoxy and its holding very well. Hope this helps any of you crazy cheap-fu mad scientists out there. Link to post Share on other sites
Redeye Posted January 18, 2006 Report Share Posted January 18, 2006 I apologize, I totally forgot I had posted this. Yes, I have replaced the spring with an M100, and (being very gentle with the shotgun) have had a very successful FPS increase, that is not really speakable on these boards. But make sure you keep the inside of the cylinder very very clean/silicon'ed as it helps the compression stay uniform, as I noticed the piston head on my particular shotgun was rather rough around the edges. There were multiple large regions missing from the edges of the piston head that would cause a noticeable decrease in combustion, so I filled them with acryllic latex caulk, which remains very supple even when dry. These two huge improvements have put the gun at an obscene fps for costing 35$, but if you do this, be very careful, as the spring guide of this gun is not a strongpoint, I reinforced my new one with some rather strong epoxy and its holding very well. Hope this helps any of you crazy cheap-fu mad scientists out there. <{POST_SNAPBACK}> So you used a standard AEG M100 spring? I was thinking these springers took and entirely different type of spring. Link to post Share on other sites
FPBBrandon Posted January 18, 2006 Author Report Share Posted January 18, 2006 It was surprising how easy the swap was, a little very light sanding on the inside of the piston with a dremel and the spring slid right in. Basically the only mod required, Id concieve they possibly used the same spring on this as they did on their MP5 series. To who asked previously about an AEG cylinder upgrade- That unfortunately seems totally unfeasible, as there would be a tremendous amount of modification required. Its a shame, Id love to do it to my own Link to post Share on other sites
jc43089 Posted February 10, 2006 Report Share Posted February 10, 2006 just me here but i wouldnt expect the upgraded shotgun to last long. the part where the pump slide attaches to the cylinder is somewhat weak so i would look for a way to make it stronger before it breaks. the circled peice is what has broke on a couple of my friends shotguns, other than that its a really good gun especially for the money Link to post Share on other sites
DarkLite Posted March 18, 2006 Report Share Posted March 18, 2006 Sorry to pull a thread revival, but do these take AEG Inner Barrels? Link to post Share on other sites
FPBBrandon Posted March 19, 2006 Author Report Share Posted March 19, 2006 Nope, these will not take standard AEG inner barrels, though me and a friend are working on a special 6.01 tightbore setup that could concievably be rather nice. Results if everything works out will be posted! Link to post Share on other sites
Docv400 Posted March 19, 2006 Report Share Posted March 19, 2006 I fitted a standard M4 barrel to mine and put on an extention to the outer barrel to cover the extra length. You have to machine the outer diameter (8.54mm) down to the same as the UTG one (8.32mm) on the section that fits in the body and machine the groove to secure it in the gun. It has noticeably more range and the fps is 280. I'm using .25s in it now. If you uprate the spring you may find the sear won't hold the piston. You can put a stronger spring on it (the sear) and carefully trim the corners where the sear catches the piston to make their engagement more secure. I removed the slam fire lever and used the spring from it on the trigger sear, it fits neatly inside the sear spring. Link to post Share on other sites
Erestheux Posted March 19, 2006 Report Share Posted March 19, 2006 Well, I just lengthened my barrel (*cough* link *cough*) and I'd like a new inner barrel to make up the length difference. But it seems as if all the inner barrels that you can buy are something like $30 or more, which is just ridiculous. I don't need tightbore or anything like that, really... does anyone know where I can get a cheap, longer inner barrel (around 16" long) that could potentially fit my UTG? And Docv400, when you say you need to "Machine" the barrel down, you can simply just sand it a real lot, right? Or do you need something more... professional? Link to post Share on other sites
FPBBrandon Posted March 19, 2006 Author Report Share Posted March 19, 2006 I was thinking AEG barrels wouldnt work because the way the hop works on these is different from an AEG, cause there is no sleeve. Cool that you got an AEG barrel on it Link to post Share on other sites
blitz Posted March 19, 2006 Report Share Posted March 19, 2006 anyone know if an upgrade set will come out? such as cylinder spring etc, as in all new metal parts Link to post Share on other sites
DanHS Posted March 20, 2006 Report Share Posted March 20, 2006 Sanding the barrel down is not likely to work, and you still have to cut the groove to secure the barrel in place. It has to be machined, I'm sure a machine shop will do if for a few dollars. I really doubt any upgrade kit will come out, but you never know, someone somewhere might do it. I would like to see if someone would machine a piston head and cylinder from brass, it would be pretty involved though. Link to post Share on other sites
Erestheux Posted March 20, 2006 Report Share Posted March 20, 2006 I wouldn't see why UTG would bother making an upgrade kit themselves, since they have like three new guns coming out soon, and the hi-cap shottie magazine. Wouldn't make much sense to have an upgrade kit for their cheapest product-- a full plastic springer. Any mod that is likely to come out will just be do-it-yourself. And thanks, DanHS, I guess if I ever find a moderately priced inner barrel, I'll check out some local machine shops. Link to post Share on other sites
Docv400 Posted March 20, 2006 Report Share Posted March 20, 2006 Erestheux... That's what they cost I'm afraid. Best bet is find someone who's fitted a tightbore in their AEG and buy their standard barrel off them. I've done my UTG shottie and a friend's now like this, although both times, the barrels were from our own guns that I've put 6.04 tightbores in. There must be lots of members that have their old barrels just sitting, gathering dust... I have my own lathe, so jobs like this are pretty easy for me. Sanding won't work, no, it's got to be precise so the barrel is concentric with the hop unit (i.e. directly in line, with no 'steps' where the hop outlet meets the barrel) As DanHS said, you need the locating groove too. FPBBrandon... The barrel, once it's machined down to the right diameter, just pushes into the hop unit like the standard one. You just get rid of the 10mm or so off the end of the AEG barrel were the hop aperture is. Oh, and if you go down to a 6.01 you may have a problem with BBs jamming unless you go for really expensive precision ones. I've also read that someone tested a 6.01 against a 6.03 and the '03 was better. Link to post Share on other sites
davecymru Posted March 23, 2006 Report Share Posted March 23, 2006 For a longer inner barrel, try the now legendary B&Q aluminium tube! It comes in Metre lengths for about £3 I used it on another cheepo springer shotgun i had to replace the original plastic inner barrel and got a great increase in accuracy. Although, that said, that wasn't firing at these sort of figures! Plus i'm not sure of the "exact" internal dimensions. I'll have to try and measure some tonight, as i know i've got some left over in my workshop. Link to post Share on other sites
Erestheux Posted March 23, 2006 Report Share Posted March 23, 2006 Hold on, I must have misunderstood you in that other thread-- B&Q makes aluminum barrels that are a bit bigger than 6mm? Probably doesn't have the little grove to secure it in front of the hopup, though, right? It seems B&Q is a UK thing, though, huh? Link to post Share on other sites
davecymru Posted March 23, 2006 Report Share Posted March 23, 2006 blast, sorry matey, i'd never noticed the usa flag! yup, B&Q is a uk DIY store. I've just checked what i've got in the workshop and the lengths i bought are 1m and the internal diameter is as near as damn it 6mm and just about 8mm external. Sorry about the "abouts", but i don't have a micrometer to hand, but i know others on the forum have used this before to good effect and perhaps they've measured it's internals? Reference the groove, all i can say is "pass me the dremmel!" I'm not going to have time to try this mod until the weekend, but i'll let you know how i get on. I'm sure you can get that in the US, but fyi I've also used this ebay shop for metal stocks before: http://stores.ebay.com/Ringwood-Precision-Engineering might be of some use? Link to post Share on other sites
Docv400 Posted March 24, 2006 Report Share Posted March 24, 2006 I've got some of the alloy tube from B&Q and it's horribly 'loose' for BBs. It's pretty close to the UTG barrel dimentions. To compare the 'tightness' of different tubes you can block one end (the forward end, not the hop end, it must be airtight) with your finger and hold it vertically with the blocked end down, then drop a BB in the top end and time how long it takes it to reach your finger. The 'tighter' the tube, the longer it takes. Use the same BB for testing each bit of tube/barrel. When I did this with my UTG Shotgun barrel the BB took 2 seconds. Doing the same with a piece of brass standard AEG barrel, only 2/3 the length of the UTG one, took nearly 6 I might try making a really long barrel for the Shottie with some next time I have it apart... Link to post Share on other sites
SlvrDragon50 Posted November 23, 2006 Report Share Posted November 23, 2006 Sry for reviving.. But Does anyone have a guide for opening up a full stock version? Link to post Share on other sites
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