- The Xtrema and Xtrema 2 utilize two synthetic o-rings, a green o-ring is used to seal the gas cylinder housing against the magazine tube. A black o-ring is used in the front part of the fore-end to seal blow-by gases from the magazine tube threads.
If the o-rings are not properly installed, the firearm will not assemble properly and create headspace issues. These issues will result in "light hits" and misfires when attempting to operate the shotgun.
From the factory the green ring should already be installed in the barrel.
In some cases upon opening the case of a new Xtrema, a black o-ring may be found in the box or stuck on the magazine tube (Image 1), this ring should be placed inside the fore-end just in front of the exhaust vents and fitted over the fore-end flange. A light application of weatherseal adhesive to the o-ring when installing it inside of the forend will keep it in place and prevent it from coming out again. (Image 2). Please allow the adhesive to dry before reassembling the shotgun.
When the black o-ring is placed properly inside the fore-end and the shotgun is assembled the black o-ring will actually be positioned in front of the gas system spring thus sealing any hot gases from the fore-end nut threads.
Do not place any o-ring on the piston or in front of the gas port holes inside the piston housing of the barrel.