niemi24s
29th September 2007, 15:49
This drawing is prompted by recent questions about link sizes and measurements and is based on U.S. Army specs for the standard "278" link. Dimensions are converted to +/- tolerance format so the posted dimension is the mid-spec value.
http://i129.photobucket.com/albums/p232/niemi24s/scan0003atxtc.jpg
The length of any link refers to its hole center spacing. Longer and shorter links (about 20) are available, and are referred to by how many thousandths of an inch their lengths deviate from that of the standard 0.278 inch. This number of thousandths is usually stamped on the side of the link.
Hole diameter dimensions and tolerances are the same for non-standard links. A Mark 17 or +17 link will thus be 0.017 + 0.459 = 0.476 inch between the far edges of the holes - provided the link holes are not worn, deformed, or modified.
The seemingly large clearance (about 0.005 inch) between the slide stop pin and the large hole is required for proper barrel/frame contact, etc., after firing.
http://i129.photobucket.com/albums/p232/niemi24s/scan0003atxtc.jpg
The length of any link refers to its hole center spacing. Longer and shorter links (about 20) are available, and are referred to by how many thousandths of an inch their lengths deviate from that of the standard 0.278 inch. This number of thousandths is usually stamped on the side of the link.
Hole diameter dimensions and tolerances are the same for non-standard links. A Mark 17 or +17 link will thus be 0.017 + 0.459 = 0.476 inch between the far edges of the holes - provided the link holes are not worn, deformed, or modified.
The seemingly large clearance (about 0.005 inch) between the slide stop pin and the large hole is required for proper barrel/frame contact, etc., after firing.