Bando Posted August 20, 2012 Report Share Posted August 20, 2012 so im looking at building a masterkey m4 and your all thinking "ok so theres a kit out there so go do it nub" problem is i want a shell ejecting master key :s so what im thinking atm is to try and run the gas parts of a maruzen m870 through the top of its receiver and into either the top rail of the m4 or into a PEQ box and what i need to feed back and any one with a m870 to take alotta pics for me XD mainly of the gas parts and the resivour. this will be a long haul project because of funds and i want it rock solid before i start so i dont waste time and money. so please help and chip in with ideas ect any time Link to post Share on other sites
notrabies Posted August 21, 2012 Report Share Posted August 21, 2012 Alright, now that you've made a separate thread I'll give you the lowdown. M870's can run off CO2 no problem. Keep pressure between 110 and 130 and you'll be fine for sure, and you probably have room to go a bit higher. The Maruzen gasline is 4mm inner diameter and 6mm outer diameter, so I've replaced mine with this: http://palmer-pursuit.com/cart/index.php?main_page=product_info&cPath=141_1_19&products_id=109 The original line sucks as you probably know, so replacing it will boost your power and reliability a bit as well as letting you run line out to your CO2 setup. As I stated before, the M870 should fit the CA870 masterkey body no problem, so that should be fine. Shell capacity depends on the model you get, my shorty has a 3+1, but the full size has a 4+1 with a +3 extension available. It would probably be in your best interest to base it off a normal fullstock M870 but be aware that the barrel on mine goes past the end of a G36 when mounted in a masterkey fashion. I have one with a hacksawed barrel that is the perfect length, but you could always get a CA870 short or medium length barrel. You may also need to cut/replace the inner barrel. If you're buying new and have the option, the M870's airsoft surgeon upgrade is your friend and dramatically ups the power. Completely worth it imo. Most important is figuring out your prospective gas system. You could run them off of a standard CO2 tank rig, but then you're gonna be tied to your gun and have the line getting caught up on your magazines. The best solution is probably finding a small 12g CO2 rig and putting it in a thick PEQ box, or even better, finding a flashlight barrel mount and put the CO2 capsule in it under your upper handguard. http://www.redwolfairsoft.com/redwolf/airsoft/Accessories_Gas_and_Related_Accessories_Madbull_XM_Charger_XC03_Portable_12g_CO2_Adaptor.htm Could work with some extra parts, as the stem part is an adapter that screws off to fit onto a normal CO2 tank, so if you screw that off, you could just put on another part that could fit the Maruzen line. Either way, project should go pretty smooth, as all you need is the gas setup, the gun, and the masterkey bodykit. All parts should fit together without a fuss. Link to post Share on other sites
DEVILHUNTER Posted August 21, 2012 Report Share Posted August 21, 2012 I had a Maruzen M870 and in my opinion is a useless shotgun. Go for the tanaka one: http://www.arniesairsoft.co.uk/forums/index.php?/topic/198742-m870-masterkey-tanaka-works-on-a-m4-gbb-r/page__hl__+masterkey&do=findComment&comment=2483042 Link to post Share on other sites
renegadecow Posted August 21, 2012 Report Share Posted August 21, 2012 Not one review is there on the web praising the durability of Tanaka shotguns. Actually most will say they're not suitable for skirmish at all and meant for display or as conversational pieces. It used to be that modified real steel parts are your only solution in fixing it which is legally questionable in some places, but I'd like to point out that TSC has just now made parts for it. Not cheap but at least there's an option now. http://shop.ehobbyasia.com/t-s-c-reinforced-breech-bolt-assembly-for-tanaka-m870-steel.html http://shop.ehobbyasia.com/catalog/product/view/id/24875/s/t-s-c-cnc-reinforced-steel-slide-for-tanaka-m870-shotgun/ http://shop.ehobbyasia.com/t-s-c-cnc-reinforced-steel-hammer-sear-connector-for-tananka-m870.html Link to post Share on other sites
DEVILHUNTER Posted August 21, 2012 Report Share Posted August 21, 2012 I have made my own bolt carrier group (you can see it in the misc custom machined parts post) but because the original were lost. It's true that the tanaka break easily, but if you know how to, it's easy as well to fix it. All you need is a couple of countershunk screws, a couple of grub screws, a file and some piece of metal. Link to post Share on other sites
Bando Posted August 21, 2012 Author Report Share Posted August 21, 2012 as RC said there is legal parts too im not too sure on the legality of the tanka shells in the uk. a mate in the MET mention that if it contains propellant and projectiles in the same thing its a nono ( so i shut up about moscarts) there's also the price the only tanaka i can find is over $500 were as the maruzen is $200ish. natrabies do you think i could run the gas parts through the top of the shotgun or will it still need to come out of the back? Link to post Share on other sites
DEVILHUNTER Posted August 21, 2012 Report Share Posted August 21, 2012 It's possible, but you will need to make irreversible mod to the reciever of the shotgun to instal a flexible hose directly in the bolt. The maruzen is much cheaper, yes, but has not any kind of upgrades. The shell carrier will break, sooner or later, and you will have a $200 wallhanger. I also fixed the maruzen shell carrier, but is much harder because you will need to make a cast and a foundry. Maybe you can make it by pressing a metal sheet, like here: http://www.arniesairsoft.co.uk/forums/index.php?/topic/190988-benelli-m1014/page__st__100 Link to post Share on other sites
NonEx Posted August 21, 2012 Report Share Posted August 21, 2012 Maruzen > Tanaka Link to post Share on other sites
sandstorm Posted August 21, 2012 Report Share Posted August 21, 2012 I'd liek to know if one can take a Tanaka apart to put the Masterkey receiver on one without breaking the porcelain and glass internals? As far as I have read on Tanakas, open one up and you don't have even a wallhanger anymore... Anyway, I guess this thread could be worth a read or two for Bando: http://www.arniesairsoft.co.uk/forums/index.php?/topic/200549-maruzen-m870-shell-ejector-thread/ Link to post Share on other sites
Bando Posted August 21, 2012 Author Report Share Posted August 21, 2012 didnt shaepe( the guy making the m1014 from the m1100) make a better shell carrier and other internals? Link to post Share on other sites
notrabies Posted August 21, 2012 Report Share Posted August 21, 2012 No, his parts are for the M1100 and won't fit the 870. I have two of his shell carriers and they're great after you do some filing and shaping, but as far as I know his project is on hold while he deals with real life stuff. I've only found one or two places that claim to stock the 870 lifter, but they're never in stock. Link to post Share on other sites
Bando Posted August 22, 2012 Author Report Share Posted August 22, 2012 hmm i may have to throw money and feral badgers at him to see if he could make me some parts Link to post Share on other sites
Doc_Glock Posted August 22, 2012 Report Share Posted August 22, 2012 @sandstorm Well all things can brake if you don't know what you're doing. I've taken apart two tanakas and put them together again and they still work fine (for now) Link to post Share on other sites
DEVILHUNTER Posted August 22, 2012 Report Share Posted August 22, 2012 +1 to @Doc_Glock I have 2 Tanakas, and I had one Maruzen. Disassembly and reassembly the Maruzen is much harder than the Tanaka, and I have take all of them apart dozens of times. One of my Tanakas receiver has ven converted on a masterky, fully reversible. About the Maruzen lifter, I haven't seen any shop with it, and I need one. The Tanaka is RS compatible, but the Maruzen is not. Link to post Share on other sites
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