What size scope rings should I use on my SIG 556?

samnev said:

What sized scope rings (exra high?) will allow my Leupold 6-5x20 Vari X III to clear the ARMS 40L-SP rear sight on my Sig 556?

Click to expand...

...the ARMS 40L-SP height above the rail is ~.610 inches or ~15.5 mm rounding up...i measured two of mine and got a hair less...

......if you take the height of the "centerline of the scope"...when mounted in the rings over the rail and subtract the radius of the occular bell housing...you will have the height of the occular bell housing over the rail...

...you need to get this from the manufacturer of the rings...or chart if one is published...

...for example...on my Leupold Vari X III 4.5-14 x 40...the occular bell housing is ~ 39.5 mm...your's may or may not be the same...you need to measure it or look up the specs for your particular scope...

...39.5 divided by 2 equals the radius or 19.75...adding in the height of the sight...ie 15.5 mm...gives you 35.25 mm...dividing that by 25.4 converts it to inches...1.39 inches rounding up...in my case i need rings that will place the centerline of the scope "higher" than 1.39 inches...i would allow about .5mm or about .02 inches clearance between the occular bell and rear sight...

...i would recomend going with the Larue QD LT-104...this will place your scope's centerline ~1.5 inches above the rail...and you can remove and remount the scope with minimum loss of zero...1 MOA or less...