I have used two methods for zeroing scopes on rifles. The MOA Method is great for a single person, while the Full Benchrest Method is a two person procedure that requires a solid benchrest.
Both methods benefit from boresighting the rifle...but you can always use a large piece of cardboard (so you can see where your bullets hit, if it's way off) to get a quick rough in.
Remember this point: The direction of adjustment on the scope is labeled for adjusting the point of impact, so when you turn the adjustment to the right, your bullet's point of impact will move to the right (the crosshairs will actually move to the left).
MOA Method:
With this method, we calculate the number of clicks to bring the point of impact into alignment with the point of aim. After firing a group measure the distance from the point of aim, to the center of the group. Knowing that at 100 yards 1 MOA is equal to 1.047 inches (which we round to 1 inch for simplicity), we can calculate the number of clicks to adjust the scope. Should we be zeroing at 50 yards, then 1 MOA is only 0.5 inch, and at 200 yards, 1 MOA is equal to 2 inches. Most scopes adjust in 1/4 MOA increments, or 4 clicks per 1 MOA. The following list will help when calculating clicks:
1/4 MOA @ 25 yards = 0.0625 inches
1/4 MOA @ 50 yards = 0.125 inches
1/4 MOA @ 100 yards = 0.25 inch
1/4 MOA @ 200 yards = 0.5 inches
For example, we have a group that hits 1 1/4 inches right and 2 3/4 inches low at 50 yards. The following would be the number of clicks to adjust:
left clicks = 1.25 / .125 = 10 clicks
up clicks = 2.75 / .125 = 22 clicks
Full Benchrest Method:
With this method, no math is required, but you need a helper and a good solid bench rest that will hold the rifle very steady while adjusting the scope. Fire a group at your target, once you have that, place your crosshairs on the center of the target and hold the rifle in the rest VERY steady and solid. This places the barrel in the same orientation as it was when firing the previous group. Now have your helper adjust the scope, remembering to move the adjustment in the OPPOSITE direction than what is labeled (see 'Remember this point' above). Without moving the rifle keep turning the adjustments until the crosshairs are in the center of your group...your point of aim will then match your point of impact.
It's also useful to keep a small notebook to record how many clicks of adjustment were made. This is helpful especially if you forget exactly how many clicks you may have adjusted during the day. This way you know you can always revert to physical zero (starting point) and re adjust back to the noted values (true zero).
ReplyDeleteIt's also helpful to note the temperature and weather conditions the day you zeroed. You'll find temperature, wind, humidity, etc will slightly affect your future zero especially at distances > 500yds.
Matty
Thank you for the comment!
ReplyDeleteWhen making scope adjustments, I mark it on the sheet, and number the groups so I can keep track of what I have been doing.
The new targets that I published today have a place to record all vital information that you mentioned as well.
Thanks for reading and commenting brother!