from my archives from the AR-15 "misc" list-
From: "Rick McDowell"
Subject: [MISC-L] One Piece Gas Rings FS
McFarland gas rings for the AR15/M16 bolts. These one piece, stainless steel gas rings replace the original, stamped steel gas rings that come on factory rifles. They are made out of a continuous spiral of stainless steel to produce a single ring that has no end gaps to worry about. They give a longer life, a better gas seal, and less breakage than the original three piece rings. 1-4 rings are $1.75 each, 5-12 rings are $1.50 each, and 13 or more rings are $1.25 each. Prices included postage.
Rick McDowell NRA Life
Competition Specialties USPSA Life, Master
105 E. Cass, PO Box 451 515-342-2011
Osceola, Iowa 50213 800-369-4481