O-rings for ACM M500

[Eeyore]

My ACM M500 shotty has developed a serious leak. It has a small one so I soaked the o-rings in sillie oil last night. I installed them today and the leak seemed to be fixed. I gasses it up to chrono it and now all the gas pisses out the barrel (it did not do that before). So I think I might have destroyed one of the o rings. I know that this shotty comes with spare o rings but I got it usd and didn't get them. Does anyone know where I can get those specific o rings? There are probably 15 in total and I'd rather not have to buy them individually.

[Boyso]

I know you can get like packs of 200 o-rings in various sizes at Canadian Tire or so. Just gotta be lucky and have the right size in that pack.

[Kos-Mos]

I had that shotgun before and don't remember having that many o-rings in the system... I think there was 3 in the gaz block and 1-2 in the hop-up/chamber unit... Maybe an other 2-3 in the magasine section, but they are not related to gaz usage.

If you want to drop by, I can take a look.

I am in Longueuil, so just let me know by PM...

[coach]

there are 2 or 3 on the back side of the gas block and 1 or 2 on the front of the gas block. those are the only ones that are related to gas leaks.

I found the oring on the back bolts/screws needed a good lube and to not over tighten when replacing it. once you over tighten or get the oring caught on a thread, it's over. you've pinched an opening for gas to escape.

the one front one that I had issue with was before the BB loader. (the round thing that rotates) I found that the round disk tends to chop that forward oring causing it to leak. my quick fix was to flip it and it has held gas fine. at least when I remember to keep gas in it but it's nothing a heavy silly oil gas fill doesn't solve.

[Drake]

Originally Posted by Kos-Mos

I had that shotgun before and don't remember having that many o-rings in the system... I think there was 3 in the gaz block and 1-2 in the hop-up/chamber unit... Maybe an other 2-3 in the magasine section, but they are not related to gaz usage.

I think you're confusing this with some other gun... in the gas block there's 3 o-rings on the valve stem alone.


@Eeyore: the design of the gas system is unusual and potentially problematic. It's quite possible you overtightened the valve stem which will cause the front of the stem to not push BACK onto the O-ring at the front of the gas block, and it'll leak from there (to varying degrees, depending on how much of a gap exists).

Here's an exploded diagram of the Marushin, which is almost identical except for a few minor variations (moreso if you're using the 6mm version):

http://tech.airsoftcanada.com/Marush...g%20M500_1.gif


Valve stem = #51
Front O-ring = #80

Make sure you reassembled it right, too.

So what you wanna do is unscrew the valve stem slightly (#58) so the front of the valve stem is resting firmly on the #80 O-ring when in battery. Unless that O-ring is totally destroyed it, by itself, shouldn't be the cause of the leak from there.

[coach]

the rings that I replaced were #81 (both), 79 and 78.

#78 was near destroyed when I broke it down the first time after buying it. both #81's were crimped by them not being seated right before the screw was tightened. #79 was chopped up a bit from #5 rotating.

I need to get a big bag of assorted orings before these ones fall apart. I don't have any more replacements for #78.