Firing Marushin's M16 Series... ***Originally posted by Madmike***

***Postedby Madmike***

I have quite a few different Marushin M16 models. As you know these models can fire quite well, but mostly they don't due to the Marushin cartridge design without gas seals and the friction caused by the large bolt carrier. I even had trouble firing one of them as it did not ignite a single round. I finally found the time to work on it and now it fires quite well.
I used my M653 M16A1 Carbine "Barnes' Rifle" conversion. It has the stronger hammer spring from the factory assembled version (made 1981) - I found the weaker kit hammer spring too weak so the hammer did not strike hard enough -, but the later, lighter bolt carrier that comes with the kits. I recommend using the lighter bolt. Then one 7 mm cap with an used, reversed cap as a gas seal is strong enough to cycle the gun properly. I also used a 7 mm and a 5 mm cap in the past but found out that this damages the cartridge rims quite badly, and the cartridges get very dirty inside (often the plastic of the 5 mm cap was melted).
A smoth moving bolt helps, but this is not the main problem. I oil the bolt lightly using gun oil or WD40.
Make sure that the bolt head fits tightly to the carrier, and that the firing rod and extractor move freely. I bought a new bolt head, extractor and firing rod. The firing rod tends to break/crack too after use. The extractor will start having play after 50 to 100 shots or more, so it may be necessary to bend it a little. This is due to the simple design Marushin uses. The MGC extractor works more elaborate and is more like the real design. I read about some guys in Japan modifying the extractor and making it spring loaded. I also know that MGCUK did such a spring loaded extractor. I will have to keep this in mind and try one out in the future.
It is vital to lube the carts inside. I used different kinds of light and heat resistant grease, but was not satisfied with the resulat at all. Now I tried silicon oil (the one you use with AirSoft guns) and WD40. Both oils work very well, but make sure to oil the inside lightly so the piston can move easily. Take care that the primer inside the caps stays away from the oil, or it will not ignite properly.
The carts I use are rather worn, but still worked okay. Two got stuck in the chamber, and I think this was because the extractor could not grap the dented rim properly.
Keeping the carts clean is vital too. I use an ultra sonic cleaner that works quite well. Anyway you will notice that the inside of the carts is showing dirt and wear, due to the movement and chemical reaction. I used small brushes and Q-tips but do not know how to get the inside really clean.
Of course the chamber and the firing pin must be kept clean. The pin and chamber are well worn, but still okay. As long as there is no rust or residue, they should work. Check that the feeding ramp is okay. Don't forget to clean and oil the magazine too, as the 20 rd magazine is steel and will rust after firing.
Regarding the loading of the carts, pleas check Cerwyn's step-to-step advice. It can't be put into words better than he did.
__________________ "It's all bullshit, Freddy - You, Figgis, are the bullshit" (CopLand)

Thanks for the tips MadMike!
I've been wanting to try my own Marushin M16 and XM177 aiming for some Auto firing. I can get single shots pretty well but Automatic? No chance!
Your hints and tips are going to be very helpful!
As for cleaning Inside cartridges, I have found that a Lyman Tumbler and Vibrating polisher excellent for the job. The exterior of each cartridge and component parts gleam after 2-3 hours of automatic polishing but the insides gets some benefit too.
If you need to, use some metal polish, Brasso, Solvol Autosol, or similar and some mascara brushes or even eye shadow make up "pads". Similar to cotton buds or Q tips but a more solid pad than cotton wool.
You can scrub the cartridge bore with these and polishing compound. Hard work and slow, but it does work!
I've added some Marushin and MGC M16 series reviews onto the relevant section which discusses your article further 'Mike
I've a handful of guns to try firing and tuning now... anbyone fancy coming over for a few days to shoot some?


Cerwyn

***Posted by Madmike***

Mate, you can't imagine how I'd like to shitcan all the files on my desk and come over to you for some serious modelgunning ...
As for the problems with the automatic mode I suggest that you check the fire selector. Sometimes the edge is worn, and the selector goes back to SEMI. Try cycling your model manually in AUTO. The hammer should fall every time when you pull the charging handle while keeping the trigger pulled. A new fire mode selector really helped on my "M 653" ...
__________________

"It's all bullshit, Freddy - You, Figgis, are the bullshit" (CopLand)

Quote :

Mate, you can't imagine how I'd like to shitcan all the files on my desk and come over to you for some serious modelgunning ...As for the problems with the automatic mode I suggest that you check the fire selector. Sometimes the edge is worn, and the selector goes back to SEMI. Try cycling your model manually in AUTO. The hammer should fall every time when you pull the charging handle while keeping the trigger pulled. A new fire mode selector really helped on my "M 653" ...

That's a handy tip to know 'Mike, I'll try that.
Should the MGC M16 (early standatrd version) do the same when cycled manually?


Cerwyn

***Post by 8ace***

Excellent tips.
I seemed to have some success with the Marushin M16 after I did a lot of tweaking (getting rid of the casting marks and making everything nice and smooth) but as soon as the bolt face, hammer, hammer spring and rounds started to ware out the firing problems returned.


8ace

Well, I have to say I like what I see here. The forum is quite user friendly and easy to view. I really like that you kept the old logo with the Automag.