Gregory Gauvin
New member
I am curious as to the rear sight height on 16" carbine length rifles with 6/3 marked elevation drums at mechanical O, or rather, the elevation drum bottomed out at 6/3.
I had been comparing my Stag Arms AR-15 16" carbine (M4gery) with my Preban Light Weight Colt Sporter. I keep all my rifles zeroed at 100 yards. My Stag is zeroed at 100 yards at 6/3 setting elevation. It has a detachable carry handle.
I just for the first time brought out my colt. It is a 16" carbine with fixed carry handle and 6/3 elevation drum. I rifles are same length, I assume sight radius the same (14.5").
My stag zeros with the front sight post (F Stamped) pretty much flush with the FSB. Using dial caliper, I measure post height (front sight base) to top of post and measured it at approximately .275".
I just recently zeroed my Colt (1978) with fixed carry handle. I noticed to hit the center X of a 100 yard SR1 target (I always shoot with 6 o'clock hold) my front sight post is not exactly flush with the FSB. I measured the post height and got a measurement of approximately .310". I am probably 2 clicks up on the front sight post from having it flush with the FSB.
I read:
"The flattop ARs have, when the carrying handle iron sight is used, a slightly higher sight line than a fixed-carrying-handle weapon. The difference is just under a tenth of an inch. Colt adjusted for this by milling the front sight deck that much higher, and to distinguish the front sight bases for use with flattop receiver, they mark each one with a prominent letter F."
Assuming my flat top with detachable carry handle sight is in spec correctly, this makes sense then that the fixed carry handle carbine with slightly lower rear elevation right would require a bit more elevation of the front post to zero for 100 yards? I know Colt never intended for these rifles to use 100 yard zeros, but rather, 300m battle zeros...it just kind of annoys me that both rifles aren't calibrated the same. Both rifles are spot on in terms of clicks for windage. I think I will start a spreadsheet now of my rifles to keep track of sight adjustments as well as data/range cards with my rifles. (All my rifles....this is going to be a project :/)
I had been comparing my Stag Arms AR-15 16" carbine (M4gery) with my Preban Light Weight Colt Sporter. I keep all my rifles zeroed at 100 yards. My Stag is zeroed at 100 yards at 6/3 setting elevation. It has a detachable carry handle.
I just for the first time brought out my colt. It is a 16" carbine with fixed carry handle and 6/3 elevation drum. I rifles are same length, I assume sight radius the same (14.5").
My stag zeros with the front sight post (F Stamped) pretty much flush with the FSB. Using dial caliper, I measure post height (front sight base) to top of post and measured it at approximately .275".
I just recently zeroed my Colt (1978) with fixed carry handle. I noticed to hit the center X of a 100 yard SR1 target (I always shoot with 6 o'clock hold) my front sight post is not exactly flush with the FSB. I measured the post height and got a measurement of approximately .310". I am probably 2 clicks up on the front sight post from having it flush with the FSB.
I read:
"The flattop ARs have, when the carrying handle iron sight is used, a slightly higher sight line than a fixed-carrying-handle weapon. The difference is just under a tenth of an inch. Colt adjusted for this by milling the front sight deck that much higher, and to distinguish the front sight bases for use with flattop receiver, they mark each one with a prominent letter F."
Assuming my flat top with detachable carry handle sight is in spec correctly, this makes sense then that the fixed carry handle carbine with slightly lower rear elevation right would require a bit more elevation of the front post to zero for 100 yards? I know Colt never intended for these rifles to use 100 yard zeros, but rather, 300m battle zeros...it just kind of annoys me that both rifles aren't calibrated the same. Both rifles are spot on in terms of clicks for windage. I think I will start a spreadsheet now of my rifles to keep track of sight adjustments as well as data/range cards with my rifles. (All my rifles....this is going to be a project :/)