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spetsnazdave87

Tokyo Marui M870 Tactical Gas Tri-shot Shotgun- picture, text and video review

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Man are you right. Tokyo Model has been trying to figure out how to take mine apart so they can ship it to me but they're worried about damaging it. They've removed the stock, trigger assembly, and receiver, but the outer barrel doesn't want to come off and there are no visible external screws apparently.  Bummer, but they're working their butts off to get it figured out. One thing they definitely confirmed is that Marui don't want no one to take it apart, or at least without a lot of effort. Apparently even the pump handle and pump arms can't come off without removing the outer barrel. Someone with the shotty in their hands please confirm/disprove this for me. Need any intel to help get this in my hands.

 

FYI, without saying too much, Korea customs will not allow importing of assembled guns sadly.

 

You'll need to unscrew the two screws either side of the barrel, and also disassemble the entire magazine shell tube too.

 

Good luck getting it back together though, I've just run that gauntlet and the nut/spacer set up that holds the mag tube on is next to impossible to screw back on.

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Two questions; Where do the inner barrels come up to on the outer barrel, and how is the front-site attached?

 

I love this shotgun and I've got one on pre-order, but the long barrel with short shelltube looks off to me, so I'm planning on either shortening the barrel or extending the shell-tube.

 

Ideally I'd want it to look like the 870 Express 7-shot, so lengthening the shell tube would be the first port of call;

 

yqYwMw5.jpg

Edited by Aod

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Ah good. I suspected that's where they'd end. Hopefully I can come up with a shell tube extension and not have to chop a brand new £300 gun to bits xD

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Woah that looks great.

 

*notes down idea for a few months time*

 

I'm not really sure if the top rail would bother me or not. If it did would it be possible to remove the rail, cut it and put the bit with the rear sight back on, then fix up any bits which are left to hold the rail? Or by that stage would it just be easier to find suitable thin piece of metal to mount a sight on and screw that on instead...

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Tbh, the bits for mounting the rail onto are pretty obtrusive, you'd have to hack up the metal body quite a bit. I don't think the rear sight on its own would look that great.

 

DSCF4640_zpsc52655f4.jpg

 

 

 

You also have to disassemble the whole front end to take the pump grip off, and once you take off the screw that holds the ring holding the shell tube to the barrel, it is IMPOSSIBLE to put it back on (or at least extremely, extremely difficult- I used all my tools I had for about two hours and couldn't get enough pressure on the bolt bit that the ring screws into to make any purchase. One of the reasons I sawed down the barrel, so I could get it back on).

 

DSCF4642_zps52ba45de.jpg

Edited by spetsnazdave87

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Hmm, well if someone wasn't wanting to actually hack the little pieces off the top (maybe one day you might want to try the rail out) you could try and make a thin piece of metal/wood/plastic to screw on that would atleast blend the mountings into the reciever and could perhaps have a small rear sight on it.

Edited by Inkall

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WANTWANTWANTWANT

 

 

The rattle in the shell tube: The springer tri shots, both the SPAS and the full lenght M3 had space in the front of the shell tube to store spare shells. I've no idea why TM did it that way, as it takes forever to get them out to do a reload, and there is no point having a seperate space on the gun to store one shell BUT, could this rattle come from the same thing(My M3 long shell tube has a spring to push the shell out into your hand so it doesn't get stuck)

 

 

As for the gas, I wonder if there is anything in the gun that would suffer when using green gas!??! Given that it's essentially a NBB system, it can't smash the slide, the most common failing of older plastic airsoft GBBs.

 

However, for myself, I think I'd like to convert it to external gas, so 80PSI of duster gas isn't such a hardship. But can the stock be removed? If so what is the gas feed like? Could a hose be attached to lead of to the external rig, or if not would I just have to build a valve to go into the socket where the current gas tank goes?

Food for thought.

 

I REALLY like the RIS, Its the biggest problem I've had with the springer tri-shots, lack of RDS!

 

Very nice review, thanks for sharing :D

 

 

{edit aditional}

 

So I've had a read of some peoples links.

Looks like there is an overpressure valve in the gun somewhere, can one of you with the gun test the pressure that it activates. (in Kratisto's link)

Also in that link, it looks like gas cooldown is TERRIBLE! Will deffinatly go over to external gas.

Edited by ED-SKaR

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could this rattle come from the same thing

It is. In Kratisto's link they show it has enough space to hold 2 extra shells which is also why the tube and the slide are wider that real steel (because TM shells are out of spec).

 

@Dave

You may find yourself wanting to buy another shotgun if and when the extended magazine tubes are released.

Edited by renegadecow

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Ed, the gas system is basically two valves pressing together with an o ring in the middle (which is easy to lose if you take the stock off).

 

The spring thing is indeed for spare shells. I've removed it.

 

It works fine on green gas, but at the moment I would say that Tm's claim of '100 shots per gas tank' is frankly rubbish. I'm getting about 2-3 shells out of each fill, so about 30 shots max. Cool down is an issue, and also the way the gas tank is designed means that it vents a bit of gas whenever you try and put the tank into the stock.

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Tm also recommends use of 134a gas. Typically, you get better gas efficiency with 134a/152a gas than green gas/propane.

 

Out of a TM G18C, I have gotten over 100 rounds on a full charge of gas using duster/152a gas. With propane, I wasn't even able to go through 50 rounds.

 

Also, there was mention of gas leaking due to over pressure. Think it may be possible yours was venting out a little? How you fire the gun also has an effect on gas efficiency.

 

Mine is inbound to the US from Japan. I will be posting my own review/findings when I get mine. Its currently summer time where I am and temps reach a high of 90-100F btw.

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How about mixing both gases? Fill half the tank with 134 and the rest with propane/green. This should give you a an intermidiate pressure.

 

Anyway, I hope the realease the necessary parts to do any of the guns below. The first two shouldnt be a problem. I plan on getting that shell tube simply by cutting the parts off of a broken tri-shot.

 

tanaka_870.jpeg
tac870.gif

gallery-SSS-DSCF0005.jpg

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Tm also recommends use of 134a gas. Typically, you get better gas efficiency with 134a/152a gas than green gas/propane.

This. 134a is more compressible as a propellant meaning you get more effective shots per volume over green gas. Plus that 100 shot figure may have been done in a warm place with lots of time in between shots to alleviate cool down.

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How about mixing both gases? Fill half the tank with 134 and the rest with propane/green. This should give you a an intermidiate pressure.

 

If you mix gases you will just end up running at the pressure of green anyway.  The 134a won't dilute it.

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Can we start planning for a shell-tube extension to upgrade the appearance of  these shotguns to a true Tactical Shotgun standard?

How long does the extension need to be, what diameter looks best and most importantly, what is the threading of the existing tube-cap? If it's metric/standard, then replacements for conversion get much easier to locate :D

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getting a real-steel 870 magazine tube extension here in the UK might be difficult, high-capacity shotguns come under a different license than low-capacity ones so the tube might be restricted. :(

 

<edit>

Not restricted apparently, just really expensive :fear2: ;

http://www.midwayuk.com/epages/Midway_UK.sf/?ObjectPath=/Shops/Midway_UK/Products/1601162456/SubProducts/162456

 

That's $144  :headbutt:

Edited by Aod
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Don't think a real one would work, think Dave already confirmed that this has wider tube than real-steel or others, as TM shells are wider, thus rendering real and curently existing forearms unfitting?

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