O Rings

Post by Dartec

Hi,

Can anybody tell me the dimensions of these o rings for 7mm and 5mm carts?

And/or where to get them from. It may be I have to buy from modelgun not a prob but just thought 25p each a lot.

On the other hand if they last a while then over time not too expense to maintain stock.

cheers
ray
_________________
Regards
Ray
Gun ethusiast and collector of modern model guns. Beretta 93r & M9, Derringer, Colt .25, Scorpion v61, V10, R31, USP

Post by GmanUK



you can get 7mm and 5mm o rings from most plumber shops i get mine form BNQ but homebase all those type of stores have them, and there quite cheap but you buy a pack of say 20+ so its all good

GmanUK

Post by Garyforce


to be honest i've never had to replace any o rings

if anything i have to replace the whole cart because they get so battered over time they become useless ! (though even with that i've not had to 'scrap' many)
_________________
- Gary

Post by Dartec

Hi Garyforce,

Some of cartridges for my MGC Beretta Italian just go 'phew' and do not eject. But the new ones work so I am putting it down to the o rings.

I always spray silicone gun oil on my carts after cleaning and drying. But just wondered does oil damage rubber and teh water/vinigar/baking soda method damage rubber?

Must invest in a sonic cleaner as they sound (oops a pun) good and effective by all accounts.

cheers
ray
_________________
Regards
Ray
Gun ethusiast and collector of modern model guns. Beretta 93r & M9, Derringer, Colt .25, Scorpion v61, V10, R31, USP

Post by metradio

You should not have any problems with silicone oil as the silicone is inert and does not react with most common substances. Not sure about vinegar or baking soda
_________________
Mike

Post by rizzo

The vinegar and baking soda should neutralise, so nothing to react there either. Besides they should be rinsed before drying and use.

Dartec, are the O rings that just go 'phew' (i know what you mean :p) have notches missing from them etc? or are cracked in any way? Or do they not seem as plump as newer ones? If so it is the O rings

Post by Claymore

A good source of O rings for the tanaka rounds and for the MGC ingram are essential as they break after a couple of shots. If anyone finds a good supply (cheap and bulk) for them let me know.

Post by Dartec

Hi rizzo,

Yes some have notches and some do seem less plump or 'pitted'. So as you say looks like the o rings.

My new carts on the Italian work no probs, look still in good shape and thats after about 6 times each. Not sure if thats good going or how many before o rings start to show their age?
_________________
Regards
Ray
Gun ethusiast and collector of modern model guns. Beretta 93r & M9, Derringer, Colt .25, Scorpion v61, V10, R31, USP

Post by Claymore

most of the 7mm O rings go on for ages but some seem to expand and become difficult to push into the body of the round, these then split or get jagged or lose a bit of rubber then they become a problem.
The 5mm rounds are just a pain the seals are so thin that they get blown off the round and dont last very long.

Lubing makes a big difference but the right lube to use can be a problem and how much to use.
I used to use a thin oil now i use silicone grease but i found too much grease in too much of the round causes the piston to stick in the cap so the gun fails to blowback properly. Silicone is good as it burns cleaner so less deposits on the detonator pin which means you can fire more rounds before they start to get stuck on the pin but if too much is used it justs gets to sticky for the round to function right.
I have been tempted to use moly grease but that can diesal in an air rifle (to much and it compeses and ignites) which would be a big problem in a modelgun.
I know mark uses a gun grease but i cannot find anything in our gunshops that i would be confident in using.

I mention the lube side of things as lubing the round correctly should in theory make the seal last longer and at the end of the day the round is the most important part of the firing sequence, if the round does not fire exactly right the gun just wont work as it should.

Post by Dartec

cheers claymore for the info.

I have been using silicone oil that I had for my airsoft. Little blue can from Den. So will stick with silicone as it seems light and lubes well for a few sprays. Need to go and get some more or similar from my local gun shop.

Not used any of my guns with 5mm caps yet so that will be my next experience. Hope to try my Glock 18c and HK USP which I think are both 5mm but look a bit more involved to load.

While searching the net for o rings found a few UK suppliers ( http://www.altecweb.com/home.asp?cat=RangeB05 ) but I couldn't work out the dimensions. According to my measuring I got 7m od and 3 id hence this post. Or the imperial size.

Another question which is the best o ring material/version:

Nitrile or Viton or Silicone?

I did think about grease but thought it too viscous.

cheers
ray
_________________
Regards
Ray
Gun ethusiast and collector of modern model guns. Beretta 93r & M9, Derringer, Colt .25, Scorpion v61, V10, R31, USP

Post by rizzo

Apparently greaseworks well too if you can source it- I use WD40 as a lubricant, although i guess i really should use silicone oil if i want to keep the o-rings in tip top condition.

Post by Claymore

I got my silicone grease from Maplins, it comes i tubes and lasts ages as you really only need a very light smear inside the case. To much and as i said the cap sticks to the round + you can get sticky deposits on the detonator pin that causes the rounds to stick.

I would really like to know what the boys in Japan use as they are the experts and maybe francky could supply use with what we need.

Post by Mark

Great discussion on O-rings guys! I too would like to know what the Japanese prefer to use. Although, it appears that most of them just use silicone oil instead of grease (of any kind)

O-rings can last a long time with the proper care but, the pressures that they are subjected to everytime that you "shoot" the cartridges really tears-up the O-rings especially when they are fired dry! Reduce the friction and the O-rings just might last longer...
_________________
Wanted to buy: MGC Sten MK3....trades?(still)

MGC MP40 Marushin MP40 Nakata MP40 TRC MP40

Modelgun manufacturers, past and present:CMC,CAW,Hudson,HWS,LS,MGC(R.I.P. 1960's~2007) Marushin,Marui,Kokusai,Shoei,Tanaka and Western Arms

Post by Dartec

Yes I very interested in the replies too.

Good idea asking the guys in Japan what they use, would like to read Francky's response and if he can supply the what ever they use.

I must say I prefer silicone it seems to cover well especially as a spray and feels really smooth and not as sticky as oil. Although I do have some silicone gun oil which is not a spray, not used yet.

Would also be interested from the guys here and in Japan if they have specialised tools for strip down etc, like a multi-tool gadget. Or is it just the odd allen key supplied and special tool supplied. Trouble is do not have the special tools as supplied, for example thje one mentioned by garyforce re: colt pocket .25 review.
_________________
Regards
Ray
Gun ethusiast and collector of modern model guns. Beretta 93r & M9, Derringer, Colt .25, Scorpion v61, V10, R31, USP

Post by Dartec

Changed old o rings for new. Primed up 30 rounds, loaded two mags, inserted into my MGC Italian and fired off both mags no probs. Rounds flying all over and quick succesion, tried the old double tap practical pistol style.

So it was the o rings and this gun is just superb. Now to clean .

BTW fired holding the gun horizontal as per some film scenes, this way the rounds go up and fall straight down so in one pile near my feet . Not all over the place if fired vertical or normal hold. May be worth doing all the time and looks a bit cool perhaps. It's a pain when the carts roll and go down the steps from the loft .
_________________
Regards
Ray
Gun ethusiast and collector of modern model guns. Beretta 93r & M9, Derringer, Colt .25, Scorpion v61, V10, R31, USP

I'm new to PFC model guns and have had a few problems learning how to use and maintain them.
My Marushin MP40 works really well as long as the firing pin in the chamber is kept scrupulously clean. The carts don't have 'O'Rings, so cleaning every time with a Ultrasonic cleaner and a light spray of WD40 keeps them clean and the smoke nicely too.
My MGC Thompson is a problem though. The firing pin and receiver is all metal, the pin is tacked into the receiver and therefore very awkward to keep clean. Ultrasonic cleaning gets the soot off but polishing the pin is almost impossible.
Any ideas anyone please?
The carts use 7mm 'O'Rings which I've been getting from modelguns.co.uk at 25p each. I'll be checking B&Q now after reading these posts!
Lubing these properly is essential, but what to use? WD40 is one option, but I'm told Silicone is much better. Which type of Silicone do you use?
There's Silicone Grease as used to lube rubber seals in car brake calipers, there's Silicone Oil for lubing car window seals and the like, and Silicone Gun Oil?
What would you guys use normally please?
Thanks in anticipation...

Cerwyn
_________________
Hobby collector of mainly WW2 era uniforms, headgear, field equipment and replica weapons.

Post by Dartec

I've been using a silicone oil in a spray can I got from Den. Need to source here and get some more.

At moment tried an Auto Siliocone Polish that seems ok for rubber, leather, plastic etc, till I get the other stuff.
_________________
Regards
Ray
Gun ethusiast and collector of modern model guns. Beretta 93r & M9, Derringer, Colt .25, Scorpion v61, V10, R31, USP

Post by metradio

Most decent DIY stores in the UK sell a silicone spray for lubricating nylon curtain tracks.. Ideal for what you want Dartec.
_________________
Mike

Post by francky1958

Hi O-ring guys!
Here in Japan, so many kinds of silcone stuff are exist.
I really recommend this one! i always use when i load the cartridges.
this grease is made by carom shot ,co for modelguns, airsoft guns.
contains 80g, this is enough for while.

***NB Original photo no longer available so I've replaced it with one of my own. Francky refers to the tube uppermost in the photo.
The lower tube is the Silicone grease available from Maplins electrical stores. Cerwyn ***




Have you ever check the inside of the cartridges? sometimes you can see
not enought smooth for the O-rings, sometimes this will damage the O-rings 'couse it after milled.
I think that silcone spray won't enought to help to reduce the friction, that's why i choose this grease.
I forgot to tell you just in case, please do not to use the oil, grease, which you have no idea what is the ingredient. sometimes it will erode the rubber, plastic and metal zinc.

francky


francky

Post by Mark

Thanks for the information on the silicone grease from carom shot Francky! That looks like it's great stuff

I too have looked at the sometimes rough finish on the cartridge internal surfaces and i have tought about trying to polish the machining marks out, but, the problem is that the inside diameter of the cartridge is usually 7mm-7.1mm and so if the tooling marks are polished out, the internal diameter changes as well...

The Hudson cartridges have this larger diameter (or smaller O-rings)and i have noted that they rarely require grease or oil..

Perhaps we all can go into a group buy on the carom shot grease?
_________________
Wanted to buy: MGC Sten MK3....trades?(still)

MGC MP40 Marushin MP40 Nakata MP40 TRC MP40

Modelgun manufacturers, past and present:CMC,CAW,Hudson,HWS,LS,MGC(R.I.P. 1960's~2007)