Nuprol 40mm Gas Grenade Maintenance

[Swuishytacos]

I just brought some grenades and the o rings snap like straight away I'm assuming it's coz of how small they are. Can anyone recommend what type I should buy to replace ?

[Tommikka]

The pricy way is with a spares kit such as this:

 

https://www.leesprecision.com/repair-kit-for-big-dragon-nuprol-40mm-gas-moscarts

 

The cheaper way is to measure them and buy from an o-ring supplier such as https://www.polymax.co.uk 

They have instructions on measuring here https://www.polymax.co.uk/o-rings/o-ring-selector/

 (or ideally find parts list/instruction manual which may have the dimensions in the part number)

 

For the type of o-ring Nitrile tends to be the most common material

[Sneaky]

Also make sure you keep them lubed to prevent them from cracking. What gas are you using as that will have an effect in the rings.

[Swuishytacos]

Just green gas it was recommended by the supplier