Airsoft Masterkey Shotgun WIP

Sandman0077 · Mar 28, 2011

So I got bored with some other projects I've been working on, and my buddy was getting rid of one of his airsoft shottys, so I figured I would screw with it. WIP as you can see, but it should only take a couple days (if I can get all the parts needed for the mount).

For those of you who don't know what a Masterkey is, it's a shortened shotgun mounted under an assault rifle, mainly for breaching doors:

The base shotgun (no idea about brand, but it's box magazine fed and spring powered):

Removed the pistol grip and heat shield:

Marking all of the cuts I need to make to shorten the shotgun:

Broke down all the internals just to get them out of the way for cutting:

More to come. I will be making the cuts either tomorrow or the next day at my buddies house. I don't have the cutting tools needed at my apartment.

EDIT: I described the Masterkey as a SHORTENED shotgun. Not necessarily, but I wouldn't want to lug the long version around haha:

'Predator' anyone?

kiddo · Mar 28, 2011

looks great! cant wait to see how it turns out!

Panzer · Mar 28, 2011

Very cool, That's one way to get a masterkey without the paperwork and heavy price tag.

SUPERprops · Mar 29, 2011

Great idea, i also like the red tiger camo on the pistol in the back.

JSteff · Mar 29, 2011

I've been bugging my local airsoft shop for years to make me something like this. I need to show them this to inspire them I think.

Sandman0077 · Mar 29, 2011

*UPDATE*

Got some good news, and some bad news.

Good news is that I got most of all the parts measured and cut. Just need to braze the metal magazine tube back together and JBWeld the plastic barrel back together. Then it will all be cosmetics. Sanding, shaping, etc..

Bad news is while cutting the charging bar, I didn't think to remove the plastic spring pistol it's connected to. Long story short, the table saw grabbed the bar and wrapped it around the blade. Oh, it also broke the piston and whacked me in the ring finger, splitting it. So sore right now.

Basically, I can get it looking all nice and pretty, but until I replace the piston, it's just a static prop. Luckily, my buddy found where he bought it, and its only a $25 dollar shotty. Shoots 350-400fps though. WOW. Cheap and strong. Well, the spring is at least haha.

More to come..

T2SF · Mar 29, 2011

There are master key adapters for the M870 in airsoft already but DIY is the best. I can't wait to see how you connect the two guns together. I'm working on another type of shotgun and trying to affix it to a AR15 airsoft.

Sandman0077 · Mar 29, 2011

T2SF said:
There are master key adapters for the M870 in airsoft already but DIY is the best. I can't wait to see how you connect the two guns together. I'm working on another type of shotgun and trying to affix it to a AR15 airsoft.

I was gonna buy one a while back, but MAN they are EXPENSIVE.

Sanded and cleaned up the back:

Using some model cement to fix the pieces together before JBWeld. Tried to braze the metal magazine tube, but couldn't get my propane torch hot enough to heat the material. I have NO idea what it's made of, but it wasn't working at all. JBWeld is the only other alternative at my disposal for the time being.

Sandman0077 · Mar 29, 2011

Glue didn't hold for crap, so I'm set back a little. I'm thinking of taking the metal tube from the new shot gun I'm buying for parts and doing it a little differently. The plastic barrel is fine for now though.

Bed time. More to come..

T2SF · Mar 30, 2011

Here is the direction I'm going. The Marushin M500 is pretty heavy so there is some engineering involved and I will have to use aluminum or another metal. The rear mount is the trickiest. I think I'll have to use the body hinge pin and hang the rear mount in the back. The front needs work as well. I was thinking of using a metal strap attached to a metal block that would slip on the bayonet lug. I'm open for ideas. One of my favorite guns but I've never seen it done before. In the movie I believe the M500 mounting was welded together. I'd like to make something semi removable and installable.

CrashDiet · Mar 30, 2011

looking good:thumbsup

Sandman0077 · Mar 30, 2011

Looks great T2SF! I thought about having a mount that slides over the bottom rails and using the end of a bayonet to lock the shotgun back in place, but I didn't think too much more about it. I'll probably end up using a M203 mount like the actual Knights Armament version. They are hard to get a hold of cheap though.

The JBWeld worked okay until I started sanding it down, then it completely broke apart. This project is going down hill quick. The only thing I can use from the shotgun now is the receiver. I'll start dressing that up and painting. I'm gonna recut the barrel and magazine tube differently to where I don't have to reattach the ends. I will just peg the magazine tube to the receiver and make a new loop mount for it on the barrel. Sucks, but not much choice.

T2SF, you are more than welcome to post pics of your progress in my thread. It can be a 'catch all' for this type of project. I'll do the M4 version, your can rock the M16 and it will give people a look at both sides.

*UPDATE*
Me and my buddy came up with a genius idea for a mounting system. Don't have the parts to do it tonight, so it will have to wait until tomorrow.

Chiok · Mar 31, 2011

I just got why a shotgun used for breaching doors is called a "masterkey". Clever. The name, not me, took bloody ages before I figured it out.

Sandman0077 · Mar 31, 2011

Got a little work done since I bought my new Dremel today.

Got the pump glued back together. Just need to fill in the gaps:

Figured out a pretty sweet and easy mounting system. Two M4 RIS rails back to back:

Fusing the two. Tried solder and brazing. I don't think my propane torch has enough kick to heat the metal high enough. Forced to use other methods. Bought some adhesive from Home Depot that supposedly holds up to 3000lbs. We shall see:

Replacement parts come in next week sometime. Hope to be finished by then.

Sandman0077 · Apr 1, 2011

*UPDATE*

Got the mount done. Just needs to be painted. I was gonna fuse the mount to the shotgun, but I might need to get into it one day for some reason, so I just drilled holes and used bolts. Easy fix:

The RIS rail fit perfectly around the under-receiver, so I decided to just cut the outer shell around the mount. Less modification to the RIS rails:

Just need the new barrel, magazine tube, and spring piston and I'm done. Might start painting tonight. Not sure. Flat black to match the M4.

Sandman0077 · Apr 1, 2011

*UPDATE*

Got everything but the magazine tube and barrel painted (those come in next week):

Project is actually coming along nicely now.

Grey · Apr 2, 2011

Is a springer shotgun actually effective? I suppose using a gas gun would be more expensive and harder to modify.

Looks cool either way.

Sandman0077 · Apr 4, 2011

Yes it is effective. Around 400fps. Gas guns are just for the cool factor I think. Not really efficient because they are expensive and hard to fix. This works fine for me at least.

JSteff · Apr 5, 2011

Thats some really great work! I'm jealous.

Sandman0077 · Apr 6, 2011

*UPDATE*

Shotgun came in. Ordered the wrong one. Awesome.
Reordered the correct one, and in the mean time I am making a mini-masterkey for my buddy with the one that came in.

He shortened his M4 barrel, so the masterkey will be extremely short.

Concept:

The mount will have to be a little bit different. Probably just a RIS mount, not the double rail I did with mine.

Thanks for all the great comments so far!

Airsoft Masterkey Shotgun WIP

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