I only have an indoor 25 yd range to zero my AR this weekend. Want a 200m zero, what would be the hold at 25?
Obviously, will need to confirm/fine tune at distance later.
Don't use hold overs. A 25 meter zero gives you close to a 300 meter zero. I know you want the 50/200. So mechanically zero, then zero at 25 meters. This will get you on paper at 200. Get to a 200 meter range and zero again.
If you can't get to a 200 meter range, zero at 25 and wait till you can.
All these techniques for zeroing are great, but you really need to actually zero at a real 200 or 300 range if that's what you want.
Probably about an inch low at 25yd. EXBAL says 1.3in low @25yd with a 55gr/3100fps with a 200yd zero. The round should rise above your line of sight at about sixty yards or so.
I thought I remebered being about 1.5 inches low at 25 to be on at 200, but it may have been closer to 1 inch low.
I"d think you split the difference and are at 1.25 inches, and that confirms take a knee too.
I'd go with the 1.25" low mentioned above, you should be close to within 1/4" of your proper 25yd zero, which will only be 2" out at 200.
The way I usually get a gun on paper is to remove the upper or bolt, solidly support the barrel and line it up on a target at 100 yds. Dial the scope or irons to co-inside with the target and I've found I'm typically within 4" of where I want to be, sometimes even closer. No ammo or range time wasted.
Also remember that at 25 yards it may look like you're zeroed, and may be for elevation. But your windage needs to be checked further out.