So I'm taking apart the gas system on my M1A the other day, finally got the shims to make sure the gas lock properly indexs on the gas tube. And as I'm taking it apart I realized the O-ring on my plug is missing. No idea what happened to it. I just want to know some thoughts on if I should replace the Ring, because I can't seem to find just the O-ring anywhere. Maybe someone knows where I can find a replacement/ knows the measurement and where to order it. Or if I should buy a whole new plug and hope I get a new O-ring. Maybe even just run the rifle without it. Appreciate any input I can get.