Moscart Grenade 40mm/27mm Takedown/Assembly Guide

[Catman]

40mm/27mm Grenade Takedown/Assembly Guide
For Moscart & Mini-Moscart (Mosquito Molds) and Similar grenades

Well anyone who's tried taking one of the Moscart grenades apart knows that it's a complete nightmare to put back together, the pesky ball bearings used in the valve system never want to stay in place.

So I'm going to show you how to take it apart and put it back together without needing a box of Nurofen.

Here I have the 40mm 180round grenade and the 27mm Mini-Moscart 36round grenades here and I'm going to cover both of them (as they differ in design).



For this guide you need a non-petroleum based grease, try your local hardware store but one of the best places to look are at R/C model shops - just ask at the counter. Other than that no specialist tools are needed.

All images are EXTERNALLY hosted! The pictures hereafter are thumbnails, if you want to see a larger version click on the image

40mm Grenade Take Down
First of all; unscrew the top section of the grenade:


Take the base section and carefully tip it upside down, All the ball bearings are going to come out so you need to be careful.


Take away the base section and heres what we got: 8 Ball Bearings, the Valve, the Striker and the Striker Sping:


That was easy! You can now replace or mess around with the o-ring on the valve if you need to - if your grenade isn't holding gas too well take the o-ring off and soak it in silicone oil overnight.


40mm Grenade Assembly
Ok taking it apart was dead easy, now to put it back together. Firstly get your Ball Bearing Ring Tool that came when you bought the Reload Tool:

What? You didn't buy that? Good because you don't need it so forget about it

What you really need is some grease and an old model paintbrush. This should be non-petroleum based grease! You don't really need a paintbrush but I find using one to apply grease much easier. Get lots of grease on the end of the paintbrush and apply it into one of the holes in the the Valve, you need to gunk-up that hole with grease (note: in the 2nd photo the bristles of the paintbrush are poking out the hole):


Now gunk up the other 3 holes with grease. Once that's done you're ready to put the Bell Bearings in. Theres two Ball Bearings per hole. Put the first Ball Bearing in from the outside and push it in a bit:


Then the 2nd Ball bearing:

[Catman]

The grease holds those pesky Ball Bearings right in there Now just put all the Ball Bearings into the holes:

 

If any Ball Bearings come out at anytime you'll have to start again and try adding a little more grease.

 

Now get the Striker and Striker Spring:

 

And put that in the Base Section like so:

 

Gently rest the valve on the top of the Striker Spring:

 

This is where it gets a little tricky...

 

Now, gently press down onto the Valve but don't press it in very far, you don't want to sink it in past the Ball Bearings. Pick up the Base section and place your finger on the back of the Striker:

 

Ok now keep your finger on the Valve so that it can't move. With your finger on the Striker; press the Striker up into the Base Section as far as it will go:

 

With the Striker all the way in press the Valve down into it's hole, once it's all the way in take your finger off the Striker:

 

The Valve is now locked into place so you can take your finger away:

If you haven't already; put a bit of silicone oil over the o-ring so it's nicely covered. Don't press down on the Valve or Striker though as you run the risk of unlocking it and having it fly/pop out. It ain't fun looking for those Ball Bearings

 

All that remains is to put the top section back on:

 

And that's it

[Catman]

27mm Grenade Take Down

Start by unscrewing the top section:

 

Once unscrewed carefully pull out the top section, the Valve unit will come with it and it will be a under a bit of resistance to pull out:

 

Now carefully tip the Base section so that the 4 Ball Bearings, Striker and Striker spring come out. It's a good idea do this into a container where the Ball Bearings won't roll away:

 

The Top section seperates from the Valve section - just pull them apart. Everything is free now, you can play around with those o-rings on the valve - or whatever you need to do.

 

 

The back of the Base Section does come off by unscrewing it:

But for the purposes of this guide and the method used, we don't need to unscrew it.

[Catman]

27mm Grenade Assembly

With the Top section on the Valve, get the non-petroleum grease and paintbrush out - you don't have to use a paintbrush to apply the grease but I find it much easier. Grease up the 4 holes at the base of the Valve - we want to gunk these up with grease:

 

Put the Ball Bearings into their holes:

 

The grease should hold them in, if they come out at any point start again and try adding a little more grease.

 

Get the Striker and Striker Spring:

 

And place them at the bottom of the Base Section:

 

Now get the Valve/Top Section and place it on top of the base like so, keep the grenade up-right for the remainder of this guide:

 

And gently press the Valve/Top Section in until it's down to the thread:

 

Now screw the Top Section all the way in and you're done

 

 

 

Feel free to post or PM me a question, also thanks in advance for any Rep points

[MistorPie]

Awosome!

[Catman]

cheers Takes a while to produce these guides - nice to know they're useful/appericated (wouldn't bother otherwise )

[Brave Sir Robin]

Would white lithium grease be OK?

 

I used petroleum jelly then remembered about the O-rings! Yikes. I will clean them out and redo.

[Catman]

yeah white lithium grease should be fine - not tried it myself though. Just double check that "petroleum" doesn't feature anywhere on the label. As long as it's a synthetic grease it's fine (no petrol/minerals).

 

Yeah give those o-rings a rub down and then some silicone oil to show you love them

[zagarol]

Wow!

 

Great guide Catman.

I have just ordered a Mosquito molds launcher with a couple of spare 40mm M203 grenades so this guide has been perfectly timed!

 

keep up the good work +1 for you

[Catman]

Cheers

 

When you read sites like Redwolf who have such a message:

 

A special note to buyers: NEVER disassemble this unit as reassembly is a nightmare requiring alignment of multiple delicately positioned ball bearings!

 

It's a bit off putting to buy such a product - hopefully this will guide will go someway to dispelling that

[Catman]

This is part shameless bump and part useful info

 

As with GBB mags, when not in use it's best to put a tiny bit of gas in them to keep the seals tight - just don't keep them loaded with BBs in case you accidentally set one off

 

If storing for long periods of time without use; put a few drops of silicone oil into the gas chamber and around the o-rings before gassing up the grenade and storing it.

[trail182]

Wow what an excellent guide!!!

 

I accidentally 'dismantled' my mates 40mm grenade recently. I then spent about 30 mins trying to work out how to put it back together. Messing about with the ball bearings was a nightmare!

 

Superb advice mate, should help plenty of people

[ronburgundy__]

What grease did you use?

[The Chef]

this sort of thing should be stickied.....

 

time well spent Catman.

[Lance Jackass]

It's peanut butter sticky time!

 

Great guide there mate. When i tried to re-assemble a moscart i cried, screamed, abused all around me and threw a chair out of the house. The bloody things are purgatory - many thanks for simplifyin things though

[Tank]

Good guide. Nice work.

 

Just a little FYI, there is a little tool they make for reassembling the valves.

 

They are pretty cheap & WELL worth the money.

 

Here's were I found mine. (bottom of page)

http://www.dentrinityshop.com/pr_list.jsp?...SPR&pg=5&rpp=10

[Catman]

cheers for the comments guys

 

What grease did you use?

<{POST_SNAPBACK}>

I'm using a discontinued grease made by Pronatur who no longer have a working website (gone bust?). It appears to be remarkably similar in constitution to the Systema Gear Grease I bought at a whopping markup

 

Any synthetic thick grease from a model shops should do it just check that what you're getting has no petroleum in it.

 

 

[...]Just a little FYI, there is a little tool they make for reassembling the valves.[...]

<{POST_SNAPBACK}>

 

I have that tool, it features in one of the pictures up top

[ronburgundy__]

Whoever asked about white lithium grease, it has petroleum in it

[Catman]

Whoever asked about white lithium grease, it has petroleum in it

<{POST_SNAPBACK}>

I couldn't find a definitive answer for that - I can only see that a lot of the white lithium sprays have petroleum in for sure. I know quite a few airsofters use white lithium grease in their gears and stuff - I've heard of a few putting it around their cylinders/psitons. But I can't find anywhere that says "product xyz white lithium grease made by abc is petroleum free"

 

So back to the old saying: Check the label, for "petroleum" written on it, check the manufacturer's website. If in doubt keep it away from rubber.

[Lance Jackass]

That valve resetting tool could be made on a lathe in minutes, surely? £10 in the UK...

[Atomic]

Fantastic guide! Thanks!

 

+1

[donthedragon]

Thanks for this mate, +1 to you!

[WildCard]

Bit of a bump, but i need help and thought this would be better than making a new topic.

 

Anywho... my moscart shell vents gas through what must be a safety valve, the one next to the load valve (where you put the gas in)

 

Anybody know how i can fix this? The valve can't be unscrewed...

[kileyhaz]

Excellent, guide, the best one I have found on the MM shells to date. Quick question, Catman, or anyone else, do you know what the size of the bearings are in case one needs to be replaced? Sadly all I can find in US hardware stores are the US Standard measurement bearings. 1/16th inch is way too small and 1/8th inch is just a hair too big

[doull76]

IIRC, the ball bearing is a 3mm one. I ordered mine from McMaster Carr. Part number 9292K33. I'll have to double check the size when I get off work tonight.