AR Sponsor
Posted: 3/16/2012 5:49:48 PM EDT
| I just bought a used TA31RCO. First, let me just say how awesome this scope is! It is worth every penny! The clarity and quality is excellent! I was just wondering how big of a difference the BDC is since it is supposed to be sighted in in meters and most ranges are in yards (at least all I have encountered). I assumed that the previous owner had it sighted in in meters since when I was shooting at 100 yards it was about 4-5 inches high (I left it alone). Now when I was shooting at set 14" steel targets 500 yards out, I had to use the 300 meter BDC on the scope. I have no problem with this but out of curiosity does this seem about right? Has anyone else had an experience like this? I just found it a little hard to believe that there would be this big of a difference. By the way I have a 14" barrel on A3 upper and shooting a 5.56 62gr bullet. |
|
A few things.
Do you have a TA31RCOM4 or TA31RCOA4? The -M4 is calibrated for a 14.5" barrel, the -A4 is calibrated for a 20". I assumed that the previous owner had it sighted in in meters since when I was shooting at 100 yards it was about 4-5 inches high (I left it alone).
Secondly, (and if I'm reading correctly) an optic moved from one rifle to another won't carry a zero. Next time you go to the range, sight in the ACOG for your rifle in accordance with this guide. An aside: ACOGs have a tendency to require a bump or two to fully seat the prism following an elevation/windage adjustment. After making adjustments, I give my ACOGs a few taps with a loaded magazine to make sure everything is settled. |
| Sweet, thanks a lot! Yeah it is a RCOM4, I don't know why I assumed that it would hold zero to a different rifle. I suppose it was because I read that you can take them off and re-mount with them holding zero, but I guess I didn't take into effect that each gun will fire different especially at different elevations. I lived in MI and moved to WY and when I first shot my AR in WY I was like 2 feet high with my old scope. Great tip on tapping the scope or gun to set the prism, I read that somewhere else too. Many thanks for the info! |
|
Quoted:
Sweet, thanks a lot! Yeah it is a RCOM4, I don't know why I assumed that it would hold zero to a different rifle. I suppose it was because I read that you can take them off and re-mount with them holding zero, but I guess I didn't take into effect that each gun will fire different especially at different elevations. I lived in MI and moved to WY and when I first shot my AR in WY I was like 2 feet high with my old scope. Great tip on tapping the scope or gun to set the prism, I read that somewhere else too. Many thanks for the info! The difference in elevation wouldn't have a caused a 2 foot change in zero at 100yds |
AR Sponsor