Shape of hicapa mag base o ring

[Stodgy]

Just a quick one. Maybe a stupid one. 

One of my hicapa 4.3 mags has starting dumping from the base o ring that seals the base of the mag to the body. I took it off and drenched it in silicone oil so hopefully it will seal again. This far no joy. 

But my main question is what shape should it be after i remove it as its a rectangular. All the pictures of replacements are round. My thoughts are even though I only purchased it 3 months ago it must be old because if it should be round but isn’t it’s seriously degraded. 

 

[Yukarin]

4 of my Hi-Capa mags have leaked from that exact o-ring, my solution was to wrap several layers of PFTE tape around it. The mags have not leaked since.

 

[Steveocee]

It's very normal for hi-capa mags to leak like this after a couple of months. I usually take bottom of, touch of silicon oil and then put back together tightening the screw down correctly.

Round replacement o-rings will be fine as they should need to be stretched to fit so take on the rectangular shape.

O-rings are cheap, if replacements are for example 20mm round with 2mm cross section, try also 19mm round with 2.5mm cross section. Gives a tighter fitting but thicker ring which should seal better (well it did in my mk23 mags).

 

[Stodgy]

Reporting back as @Yukarin said the ptfe option seems to have worked so I thank you for that. Bit rubbish that I have to resort to such a bodge but it is what it is. 

 

[Iceni]

Measure the original and buy more. It's only an o-ring and it'll only have 2 dimensions.

Thickness as a diameter.
The internal diameter of the ring.

With those 2 measurements, you can just as easily buy 50 rings as 1. Since the gun runs propane you will want nitrile or buna-n rings. EDPM and natural rubber will be dissolved.

https://simplybearings.co.uk/shop/Seals-O-Ring-Seals-NITRILE-O-Rings/c19_4501_4705/index.html

 

[Yukarin]

Reporting back as @Yukarin said the ptfe option seems to have worked so I thank you for that. Bit rubbish that I have to resort to such a bodge but it is what it is. 

hasn't failed me yet so personally better imo than changing o-rings every now and then.

 

[Steveocee]

Reporting back as @Yukarin said the ptfe option seems to have worked so I thank you for that. Bit rubbish that I have to resort to such a bodge but it is what it is. 

PTFE isn't a bodge. It's a lifeblood of Airsoft weapons lol.