Iirc other manufactures don't use magno valves either, which in theory are far superior to spring valves. Dye has a system where the bolt rides through a tube which protects the eyes. The bolt will blow or scrape any debris down the tube thus "cleaning " the eyes. The flaw with this technology is that I have seen these thin plastic tubes crack and break alot at my local field.
"There he goes. One of God's own prototypes. A high-powered mutant of some kind never even considered for mass production. Too weird to live, and too rare to die." -Hunter S. Thompson