Aguila Blanca
Member
Part 1 was here: http://www.thehighroad.org/showthread.php?t=154455
Thanks to 280Plus, I got to an outdoor range offering a 200 yard field of fire, so I was able to play with the Olympic Plinker. For those who didn't follow the original discussion, the "Plinker" is Olympic's entry-level AR carbine. It has a 16" barrel, and A1 style sights. And just about all the info on zeroing an AR deals with A2 style sights.
So here's what 280Plus and I discovered. First, there is no discernable difference in aperture size between the two rear sight blades. So one is not intended for low-light. Also, although a reprint of a gummint M16 manual suggested that one aperture would be marked with an "L" to designate the long-range sight, the Olympic rear sight (mine, anyway) is unmarked.
So I began on the assumption that, marked or not, I was probably dealing with a short-range/long-range sight, and I flipped it back toward me for initial zeroing at 25 yards. It only needed about three 5-shot groups to get pretty well dialed in at 25 yards. Then, as a test, I flipped the rear sight forward )to the position that the manual indicates should display an "L" beneath the aperture). Sure enough, a 5-shot group with the rear sight in that position came in about 2 to 3 inches above point of aim.
The manual says the 25-yard zero with the close range sight corresponds to a 200-yard zero, and that flipping to the long-range aperture extends the same zero out to 375 yards. Extrapolating from the 25-yard results, I'll conjecture that this seems to be born out.
Next, we flipped the rear sight back to the short range aperture and set up at 200 yards. My group was a couple of inches below the point of aim, but certainly more than close enough that it would have been a hit on a huminoid target. I didn't attempt to adjust to get a true 200-yard zero, because I don't honestly think I'm likely to be shooting anything or anybody at that distance anyway. As it came out, I'm probably pretty well zeroed for 100 to 150 yards, and even out to 200 yards and beyond I'll be close enough to scare 'em away.
Summary: The Plinker iron sights are a long-range/short-range setup, NOT a daylight/low-light setup. Procedure is to flip the rear sight back toward the shooter and zero at 25 yards, then move out to 200 yards and confirm zero.
DMK, you were right ... it is simple. Just don't try to do it by reading any of the commonly available Internet articles on how to zero an AR-15, because for the Olympic Plinker they will be incorrect.
BTW -- I used four different magazines: the 10-rounder that came with the rifle, one 20-round mil-surp, and two 30-round mil-surps. I'm happy to report that there were NO malfunctions. One of the 30-rounders is a slightly tight fit and needs to be removed manually rather than dropping free of its own accord, but that was the only "glitch" encountered. For someone looking to get into an AR on a limited budget, I wouldn't hesitate to recommend this little carbine. (And the new ones are even better -- mine is the old model with the cast lower.)
Lastly, the instructions in the Olympic instruction manual (and on their web site) are not incorrect, but they don't discuss the two apertures on the rear sight at all and, therefore, are next to useless without some additional information from outside sources.
Thanks to 280Plus, I got to an outdoor range offering a 200 yard field of fire, so I was able to play with the Olympic Plinker. For those who didn't follow the original discussion, the "Plinker" is Olympic's entry-level AR carbine. It has a 16" barrel, and A1 style sights. And just about all the info on zeroing an AR deals with A2 style sights.
So here's what 280Plus and I discovered. First, there is no discernable difference in aperture size between the two rear sight blades. So one is not intended for low-light. Also, although a reprint of a gummint M16 manual suggested that one aperture would be marked with an "L" to designate the long-range sight, the Olympic rear sight (mine, anyway) is unmarked.
So I began on the assumption that, marked or not, I was probably dealing with a short-range/long-range sight, and I flipped it back toward me for initial zeroing at 25 yards. It only needed about three 5-shot groups to get pretty well dialed in at 25 yards. Then, as a test, I flipped the rear sight forward )to the position that the manual indicates should display an "L" beneath the aperture). Sure enough, a 5-shot group with the rear sight in that position came in about 2 to 3 inches above point of aim.
The manual says the 25-yard zero with the close range sight corresponds to a 200-yard zero, and that flipping to the long-range aperture extends the same zero out to 375 yards. Extrapolating from the 25-yard results, I'll conjecture that this seems to be born out.
Next, we flipped the rear sight back to the short range aperture and set up at 200 yards. My group was a couple of inches below the point of aim, but certainly more than close enough that it would have been a hit on a huminoid target. I didn't attempt to adjust to get a true 200-yard zero, because I don't honestly think I'm likely to be shooting anything or anybody at that distance anyway. As it came out, I'm probably pretty well zeroed for 100 to 150 yards, and even out to 200 yards and beyond I'll be close enough to scare 'em away.
Summary: The Plinker iron sights are a long-range/short-range setup, NOT a daylight/low-light setup. Procedure is to flip the rear sight back toward the shooter and zero at 25 yards, then move out to 200 yards and confirm zero.
DMK, you were right ... it is simple. Just don't try to do it by reading any of the commonly available Internet articles on how to zero an AR-15, because for the Olympic Plinker they will be incorrect.
BTW -- I used four different magazines: the 10-rounder that came with the rifle, one 20-round mil-surp, and two 30-round mil-surps. I'm happy to report that there were NO malfunctions. One of the 30-rounders is a slightly tight fit and needs to be removed manually rather than dropping free of its own accord, but that was the only "glitch" encountered. For someone looking to get into an AR on a limited budget, I wouldn't hesitate to recommend this little carbine. (And the new ones are even better -- mine is the old model with the cast lower.)
Lastly, the instructions in the Olympic instruction manual (and on their web site) are not incorrect, but they don't discuss the two apertures on the rear sight at all and, therefore, are next to useless without some additional information from outside sources.