ATT: ALL M500 Shotgun Owners! USE YOUR GUN IN THE COLD!

[ProbeJax]

I know a guy who'd do it for chump change.

[hattrick]

links down, help?

[Drake]

So I was playing around inside my M500 today. I opened up the gas block to lube the o-rings (all you M500 owners should really do this, mine were bone dry!) and I noticed at the back of the reservoir there's a ~1/2 inch screw plug. It really doesn't seem to serve any purpose other than to plug the opening at the back of the reservoir, and I have no idea why they put it there (considering the rest of the gas assembly is built as one massive piece of metal). Looking at the schematics for the Marushin version, it seemed to be built the same way.

At any rate, looking at how it was set up inside the gun, it would be a good spot to add a screw-in valve directly into the back of the reservoir, if someone could find a 1/2" one that fits (someone else would need to identify the exact size/threading).

It faces back into the trigger pack, but the way the hammer is built (sorta L-shaped, hitting the valve like a hockey stick or golf club would) there's place to snake a gas line through the trigger pack, towards the back end of the receiver (and potentially into the stock). I think that space under the hammer is for the fake bolt to move back, but it doesn't appear to have any functional use so it could be either modified or outright removed. And considering the stocks are hollow, it would be a great place to hide a small regulator and CO2 tank (or two smaller/slimmer tanks on a manifold).



PS. the thing is built like a tank. The walls on the receiver are a whopping 5.3mm thick! The "airsoft bits" (internals) weigh practically nothing, all the weight on these things are the body, barrel and ammo tube.

[aZn_triXta07]

Originally Posted by hattrick

links down, help?

I saved a copy of the thread at home, I'll post it up when I get off work in the AM.

Originally Posted by Drake

So I was playing around inside my M500 today. I opened up the gas block to lube the o-rings (all you M500 owners should really do this, mine were bone dry!) and I noticed at the back of the reservoir there's a ~1/2 inch screw plug. It really doesn't seem to serve any purpose other than to plug the opening at the back of the reservoir, and I have no idea why they put it there (considering the rest of the gas assembly is built as one massive piece of metal). Looking at the schematics for the Marushin version, it seemed to be built the same way.

At any rate, looking at how it was set up inside the gun, it would be a good spot to add a screw-in valve directly into the back of the reservoir, if someone could find a 1/2" one that fits (someone else would need to identify the exact size/threading).

It faces back into the trigger pack, but the way the hammer is built (sorta L-shaped, hitting the valve like a hockey stick or golf club would) there's place to snake a gas line through the trigger pack, towards the back end of the receiver (and potentially into the stock). I think that space under the hammer is for the fake bolt to move back, but it doesn't appear to have any functional use so it could be either modified or outright removed. And considering the stocks are hollow, it would be a great place to hide a small regulator and CO2 tank (or two smaller/slimmer tanks on a manifold).

PS. the thing is built like a tank. The walls on the receiver are a whopping 5.3mm thick! The "airsoft bits" (internals) weigh practically nothing, all the weight on these things are the body, barrel and ammo tube.

Do you think you could post up a step by step on disassembly, re-assembly? Noobs like myself aren't very good at exploring things on their own. Do you mind taking pictures of the resevoir?

I was thinking of taking the resevoir out to a hobby store cuz the gas valve apparently can fit with air brush fittings (not sure) but that could be an option instead of drilling.

I can look on the Palmers site to see if they have anything for 1/2' fittings if they do it sounds like it'll work.

[Murdoch]

I posted some pics for Kook in the Doctor's Corner section. They're not close up but it might give you an idea. The gun is still apart on my worktable so if you want better pics I can take them easy enough.

It looks to me that the trigger assembly would be in the way of that threaded cap. I think it was there to make it easier to machine the gas chamber (just a guess).

M

[aZn_triXta07]

Originally Posted by Murdoch

I posted some pics for Kook in the Doctor's Corner section. They're not close up but it might give you an idea. The gun is still apart on my worktable so if you want better pics I can take them easy enough.

It looks to me that the trigger assembly would be in the way of that threaded cap. I think it was there to make it easier to machine the gas chamber (just a guess).

M

Thanks, if possible could you take more pictures on getting the gas resevoir out? I need to send it out to someone to preform the drill/tap for me

[Drake]

Originally Posted by aZn_triXta07

Do you think you could post up a step by step on disassembly, re-assembly? Noobs like myself aren't very good at exploring things on their own. Do you mind taking pictures of the resevoir?

I was thinking of taking the resevoir out to a hobby store cuz the gas valve apparently can fit with air brush fittings (not sure) but that could be an option instead of drilling.

I can look on the Palmers site to see if they have anything for 1/2' fittings if they do it sounds like it'll work.

Murdoch's guide is perfect, plus there's only two steps needed to get to the reservoir:

1) remove the stock, take out the screw in front of the trigger guard and knock out the pin holding the trigger pack in, then remove the trigger pack by pulling it out;

2) rack the forend back, push the gas block to the back of the receiver and pull it out.


The shotgun is well designed, there's no spring loaded bits to fly out all over the room during disassembly and very few loose parts (like the whole tirgger mechanism is held together in a single package).

As Murdoch pointed out, the trigger pack is generally in the way, but I think there's enough space there that if the plug was something you could connect a small gas line to, it might just barley fit. There's not a whole lot at the front center of the trigger group, just some springs at the bottom of the pack and the arms on either side. I think if you snake the gas line through the L shape on the hammer you could get to it.

Personally I'd want to run it off those 88g cartridges (Crosman Air Source etc). Convenient and probably small enough to fit a stock.

[aZn_triXta07]

Originally Posted by Drake

Murdoch's guide is perfect, plus there's only two steps needed to get to the reservoir:

1) remove the stock, take out the screw in front of the trigger guard and knock out the pin holding the trigger pack in, then remove the trigger pack by pulling it out;

2) rack the forend back, push the gas block to the back of the receiver and pull it out.


The shotgun is well designed, there's no spring loaded bits to fly out all over the room during disassembly and very few loose parts (like the whole tirgger mechanism is held together in a single package).

As Murdoch pointed out, the trigger pack is generally in the way, but I think there's enough space there that if the plug was something you could connect a small gas line to, it might just barley fit. There's not a whole lot at the front center of the trigger group, just some springs at the bottom of the pack and the arms on either side. I think if you snake the gas line through the L shape on the hammer you could get to it.

Personally I'd want to run it off those 88g cartridges (Crosman Air Source etc). Convenient and probably small enough to fit a stock.

Awesome I'll look into it on one of my days off really looking forwards for the upgrade

Depends how much room it'll take for the 1/2' connector before you can stick the macro line in unless you could use a mini than to a macro in the stock.

Are those 88G cartridges refillable? If not it'd still be good cause you'll get nice consistent shots for a while. I don't mind the air rig cause of my current setup.

[llotech]

Originally Posted by aZn_triXta07

Thanks, if possible could you take more pictures on getting the gas resevoir out? I need to send it out to someone to preform the drill/tap for me

If you don't have someone to drill and tap for you, pm me. I can do it.

[aZn_triXta07]

I decided I wanted to avoid drilling/tapping simply because if I ever get rid of the gun not many people here would want a gas line coming out of a shotgun :P.

I believe the gas fill valves for the majority of airsoft guns are sized M3 threading. I just ordered some parts to screw right in and than attach directly to my external air rig. Hopefully this'll work out, if so I will even try it out on my GBBs for some cold weather fun :P

This'll be a sweet alternative for owners of the KWC Mini Uzi, no more need to change out the 12g CO2 Cartridge so often :P

[Drake]

Originally Posted by aZn_triXta07

I decided I wanted to avoid drilling/tapping simply because if I ever get rid of the gun not many people here would want a gas line coming out of a shotgun :P.

I believe the gas fill valves for the majority of airsoft guns are sized M3 threading. I just ordered some parts to screw right in and than attach directly to my external air rig. Hopefully this'll work out, if so I will even try it out on my GBBs for some cold weather fun :P

This'll be a sweet alternative for owners of the KWC Mini Uzi, no more need to change out the 12g CO2 Cartridge so often :P

Nice, let us know if that works. I'm still trying to find what size that plug on the back of the gas block is. It's really close to the trigger group though, so might be tricky using that.

Wonder if anyone could machine a custom part that could screw in and feature a recessed QD plug for the remote line. Then CO2+reg could live in the stock. I'm pretty sure that would be popular with M500 owners everywhere.

[aZn_triXta07]

Originally Posted by Drake

Nice, let us know if that works. I'm still trying to find what size that plug on the back of the gas block is. It's really close to the trigger group though, so might be tricky using that.

Wonder if anyone could machine a custom part that could screw in and feature a recessed QD plug for the remote line. Then CO2+reg could live in the stock. I'm pretty sure that would be popular with M500 owners everywhere.

You said that the screw in the back was about 1/2" right?

Should be able to find something that'll fit into it, the hoses are small enough they should be able to fit through the internals, the current hose that I'll be using for this setup is 1/8" in outer diameter.

Did you also consider on removing the gas resevoir entirely? Is that even possible :S cause if it is than that'll free up alot of space for fittings.

[Drake]

Originally Posted by aZn_triXta07

You said that the screw in the back was about 1/2" right?

Should be able to find something that'll fit into it, the hoses are small enough they should be able to fit through the internals, the current hose that I'll be using for this setup is 1/8" in outer diameter.

Did you also consider on removing the gas resevoir entirely? Is that even possible :S cause if it is than that'll free up alot of space for fittings.

I'll take a pic and accurate measurements tonight. I picked up a paintball -sized fitting (not sure what the exact size/nomenclature is) for comparison and its a bit too big unfortunately.

As for removing the entire reservoir, the Marushin designs (for their shotguns and revolvers) have all the valves built around the reservoir as a solid block, so everything is just one piece (same for the trigger; makes disassembly a breeze though!)

[Long_Bong]

Any update on this mod?

Would changing the barrel in that shotgun be worth it?

Also, Hop Up wise, there is none I believe?

[aZn_triXta07]

Palmers messed up my order so they got me the wrong fitting. I've also been quite busy so haven't had time to put it together.

I also bought the wrong fitting to connect to my QD. But so far looks good.

I just say change the rails for the handguard.

I wouldn't recommend changing a barrel on any airsoft shotgun.

Originally Posted by Long_Bong

Any update on this mod?

Would changing the barrel in that shotgun be worth it?

Also, Hop Up wise, there is none I believe?