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renegadecow

Cheap Marushin handgun shells

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All this started from the news thread about the Marushin shell ejecting CZ75. Plenty of people want it as well as the other models, but can't think of even skirmishing it. Generally speaking, shell ejection is the absolute state of realism that an airsoft gun can attain. But you have to pick them up as spare shells are unbelievably expensive. So I thought semi-disposable shells made of plastic or even better, some kind of biodegradable material. I experimented with my Mateba revolver, a wheel gun essentially but it uses rimless cartridges used by autos. My initial plan was to roll up strips of paper into the shells and harden them with water based glue and acrylic emulsion. The end result somewhat worked but the wall thickness was just too little to support itself if stacked in a magazine.

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So I went to the mall to buy myself a hard-case for the shells when I saw a nice big pile of brand new, un-primered shells. I remembered not long ago in playing around with my Mateba that its shells weren't actually 9mm as stated but measured more closely to a .40 S&W. So I purchased a bag of fresh shells for about $15 for 100pcs. Checking back home with the new shells, I found that the real shells do indeed fit.

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*disclaimer*THIS IS NOT ABOUT FITTING REAL BULLETS IN TOY GUNS TO MAKE THEM FIRE*disclaimer*

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There were a few differences but none too big a problem.

All photos of shell comparison have the Marushin shell on the left and the real one at right.

Discrepancy #1: The real shells were too long by about 0.7~1.0mm

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Discrepancy #2: The primer pocket and hole acts like a flow limiter

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Discrepancy #3: The Marushin shell has a rubber bucking inside to hold a bb

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So I filed down the case and drilled out the primer pocket. I didn't bother enlarging the hole at the rear to seat an o-ring because if I cut the shell to just the right length, it would seal up against the valve on the gun just as neatly. I purchased some 1/2" and 5/16" transparent plastic tubing from the hardware to make the bucking. Tubes cost $1 for 2m of each tube size.

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Cross section of my bucking design (red).

shellcrosssection.jpg

It's made of 3 pieces: the main tube that holds the bb (5/16" will hold 8mm, 1/4" will hold 6mm), the short ring that tightens the forward end of the main tube, and the spacer at the rear to keep the bb from going too deep.

 

All three components of the bucking

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Assembled components

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Bucking fitted in completed shell. No glue required; all held in by friction. ^_^

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Testing it out in the garden surprisingly revealed that the real shell shot at a considerably higher power since it caused the bb to arc skywards even though the hop was set to fly straight when used with the Marushin shells. I couldn't believe it myself so I put on my mask and shot myself in the gut (too poor to buy a chrono). For half a second I thought it didn't shoot any harder than before until the other half of the same second came about. I was literally doubled over, clutching at my stomach from the pain. I had chronoed the gun before to do 240fps with .34g bbs using 134a. It was now doing something like 300, maybe even more. The only reason I could think of as to why its grown suddenly stronger is in my bucking design. The Marushin bucking hardly held on to the shell. In fact, I find the shells to pop out if the handgun is so much as jolted like if I land from jumping down and its holstered. The new bucking really holds the bb, about as much as Tanaka buckings do and could mean increasing the pressure behind the bb before its released as opposed to the original bucking which would let go of the bb the moment any amount of gas comes through.

 

Lessons learned:

Stop using my stomach as a chrono with guns of unknown power. -_-

My improvise shell, although made for a revolver (thats made to use auto shells), can be implemented to other models only changing the host shell if necessary. This means that the shell ejecting curiosities can now be fielded without fear of losing expensive shells. MY SHELLS COSTS 16 CENTS EACH!!! That and if someone picks up your empties and ushers them back to you you could arrogantly reply "I only shoot virgin cases" <_<

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Top job renegadecow :P

I love stuff like this, when people find a way round paying stupid prices for Airsoft specific stuff.

To improve on the original and do it significantly cheaper is fantastic.

Have a virtual beer on me ;)

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Takes virtual beer

materializes it into an actual bottle of beer

puts it on sore stomach

-cheers

 

The real problem now is convincing myself not to deplete my funds in buying the shell ejecting CZ.

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Takes virtual beer

materializes it into an actual bottle of beer

puts it on sore stomach

-cheers

 

The real problem now is convincing myself not to deplete my funds in buying the shell ejecting CZ.

 

Nice, tol.

 

I wonder if I can do something similar for my Redhawk...

 

:thumbs-up:

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After maybe 3 hours of churning shells like mad, I have a bit of a production tip to add.

The rubber/plastic hose isn't very uniform in diameter all throughout which affects the amount of pressure of the bucking holding the bb (which may or may not affect performance, I assume it does). So I scrounged around for a metal tube roughly equal or slightly larger than the bb and came up with a scrap piece of 6mm inner barrel. Its OD measured 8.6mm so I just gave the outside a light sanding and polishing bringing it down to 8.5mm . Now the trick is to fit the bucking (parts one and two) over the improvised tool and apply some heat. I used a lighter and takes around 2~3 seconds. More and it catches fire.

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The plastic/rubber tube, being thermoplastic, will shrink or expand to fit the tool and remember the shape when its cooled. This makes for consistent bucking tightness plus the edges of the tube are slightly rounded from the heat making things extra tidy.

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For the redhawk, you might have to find a separate tube for that necked down front part as I don't think any of the magnum cartridges have that feature.

 

Have another ice cold virtual beet. :D

I'd rather have a cookie than a frigid vegetable <_<

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Have a virtual whiskey on teh rocks ;)

This better be Wild Turkey.

 

My tummy doesn't do ROF... but my socks do.

Shoot into doubled over socks for exactly one second and count how many bbs there are inside. Helps if you wear earmuffs so the gun won't distract you. The more seconds you fire, the more precise the reading.

 

Production cost rose to 17 cents each. Had to put some silicon sealant as an adhesive for the bucking. The shell liked to puke it out when dropped on the floor.

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I now have no reason not to to buy a mateba.

 

Now, just have to choose between Marui Five-seveN and Mateba.....

 

Curse you.

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I'd just like to add, before someone else wastes their time as I have, TAKE YOUR TIME MAKING THE BUCKING. All that frantic effort to make short work of my 100pc pack of shells went to waste. Some were too long and would interfere with the fit. Some were too tight and would end up not spitting the bb out upon firing. Then theres the variance between light to tight buckings which would invariably screw up with your pre-adjusted hop up. In about 35 shells that I made, I was only able to get 6 really good ones; the rest I had to do over. Now I'm doing it slow and have 21 shells.

 

I now have no reason not to to buy a mateba.

Best you check out my review to give you a glimpse of what you're getting into. Lotsa problems like cylinder timing and the kinked barrel. The hump on the inner barrel which I went mad about for weeks is apparently part of Marushins design for God knows what. Took me a while of research and found they do the same to the SSB shotgun. My guess is it's to limit the power since mine took up some (20~30fps) when I hammered the barrel straight. Still a very lovely gun though and there's the fact that you're unlikely to ever see another one in the field if you choose to get one.

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Having a bit of fun here, I thought of making a 6mm shell. But since the the large 8mm shells were kinda big, loading 3 would be possible. The inner barrel is still for the 8mm though so the groupings are near silly henceforth I present the BS (buck shot) shell. ^_^

BS6mmcrosssection.jpg

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I've only made one and testing it out doesn't seem to do any harm to the inner barrel. But I imagine unloading six of these in a tight room would be massively entertaining.

 

edit:

This would work great on the 2" revolvers by Marushin as they have no accuracy to speak of from the start. They make something similar for real guns too as defensive rounds, if your gun isn't big enough to bludgeon the enemy with.

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Dude this is brilliant! Does anybody know if those shells of anything similar are available here in the UK? I've always wanted a revolver for the back garden, this would be sweet!

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heh, this hes renewed my want for the mateba. luckily, wood versions are still available and i can still get that precision barrel i was talking about transplanting a while ago. remember our PM fiasco about the mateba RC?

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Dude this is brilliant! Does anybody know if those shells of anything similar are available here in the UK? I've always wanted a revolver for the back garden, this would be sweet!

 

Midway UK for one. Sure you can get shells at your local gunshop too. Just not sure about the legality of buying even the empty cases if you don't have a licence. I'd go for the local gun shop first. Probably save on postage.

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i can still get that precision barrel i was talking about transplanting a while ago

Been mulling over that myself. TN barrel plus the right die to thread the front would only run $50.

 

DIY airsoft snake shot.

More like Armscor Strike Three actually. Made in my own country too and is probably where my subconscious got the idea. "Precision" indeed. :P

AM357-S3-D.jpg

I've made 5 more of these shells by the way. Will test how they work in skirmish later.

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This is a really interesting and useful construction you've produced.

Also, it would be nice if anybody tried this method on any of the shell ejecting Marushin guns on the market. A shell ejecting Glock 21 or Kimber with cheap shells would really be a godsend (given that the cost of letting the shells lay where they land would not ruin the owner).

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Very nice job. I love it when people share stuff like this.

 

I actually found that RS .44 Rem Mag rounds fit in my Marushin Super Blackhawk the other day. This makes me want to investigate the possibility of working up a similar shell. I guess that it would be more complex though since I would have to have a smaller inner tube to extend beyound the shell. On the upside, I might be able to make a 6mm conversion. Thanks for getting me thinking.

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