Open gun zero?

[rtr]

In preparing for nationals, and for shooting in general I'm re-thinking my zero.

Gun is a major 9 shooting 124grain Montana Gold CMJ, the last time I chronoed with Greg Lent I made about 170pf, so thats 1370-1375fps.

I'm using an 8MOA cmore mounted on a dawson mount, in the past I have had some issues with head shots on close in targets and the offset causing me problems.

So what do folks recommend as a zero, and what would the offset be for some common distances?

[lynn jones]

20-25 yards works just fine.

lynn

[Flatland Shooter]

I zero my open gun (C-More) at 25 yards.

In March I shot the Double Tap Ranch Championship and came across a target that after activation a N/S covered everything below the A zone on the head. Since this target was only a few yards away, I really didn't know where to aim. With the C-More mounted so hight, I was concerned that at very close range aiming for the center of the A would result in a penalty hit. (I ended up aiming high for an A and a B.)

When I returned home, I took a target to the range and placed 5 "+" marks on the target and labeled them for 3 yards, 6 yards, 12 yards and 25 yards. With the gun zeroed for 25 yards, I then shot the appropriate "+" sign at each distance just to see what would happen.

Consider trying this before you end up at a match with tight targets. It may save you a few points.

Bill

[shred]

18 yards = top of dot. Your bullet will be 'in the dot' out past 50, and you gain a little up close.

[spooledup]

+2 on 25 yards at top of dot.

[rishii]

16 yards at the top of the dot, I read that somewhere from matt burkett.

works good out to 50 yards. of course ymmv.

[Josh Biondi]

25 yards .....of course!

[PaulW]

+1 what Shred said.

[XRe]

I set the gun up so that the bullet is cutting the top of the dot at 35. If you run the calculations, and do the shooting, it changes the point where the bullet enters the dot at the bottom at close range very little, and you gain a flatter trajectory within the dot - and a precise aiming point for tighter, longer shots.

I used to put the bullet at the top of the dot at 50, but moved back to 35 a while back.

In practice, putting the bullet at the top of the dot anywhere from about 15 yards and out will give you a workable zero for this game - you just need to know exactly what it does to your holdover at closer ranges (point blank being the biggest adjustment, of course...)

[Joseph796]

Shots further than your zero distance will be high & shots lower than your zero distance will be low. Are your less than perfect shot (aka, misses) tendencies high or low? Zero in accordance with this. If you tend to shoot high, then I would zero at a longer distancer (25 or 30 yards). If you tend to shoot low, then I would zero at a shorter distance (10 or 15 yards).

[LPatterson]

The dot in the Optima is so small that I don't worry about whether the target area is at the top or bottom of the dot so I zero at 15 yards because that is the average distance for targets in this area.

For this years Nats practice I would spend a lot of time finding out how much hold over is needed for 5-15 yard head shots as there are 21 in the match & 15 on 1 stage, another 7 have no-shoots covering the lower A zone. The 1/2 hard cover & 1/2 no-shoots are only a problem for a sloppy transition as it looks like a lot of aiming is required.

[old john]

The Sierra program will show 16-18 yards center of dot to be the best zero out to 50 yards. Old John

[Tom Freeman]

15-20 yards.

[XRe]

Shots further than your zero distance will be high & shots lower than your zero distance will be low.

Not (necessarily) true. In my case (and most of our cases, I suspect), sighting with the bullet crossing the top edge of the dot at 35 yards, the bullet is at the apex of its flight when it intersects the top edge of the dot at that range. So, from approximately 10 yards out past 100, the bullet is in the dot. Anything inside 10 yards will be slightly low, up to point blank where it'll be around an inch and a half low. You only have to adjust inside 10 yards, and then (because our A-zones are so damn big) only when you have a tight show below the point of aim (or when you have a head-only shot, and you want to hit A-zones).