Sight Above Bore

[04rafz 0]

Hi guys, was wandering an easy and accurate way of measuring the height of sight above the bore, I'm using a ballistic data app now to dial in shots and its asking the height of sight above the bore. I used a standard ruler and placed it from the middle of the bore and measure up to the horizontal plane of the crosshairs is this accurate enough ?

 

Any advice would be appreciated

[gunner223 0]

I would sat it is, I only ever estimate it myself.

[dicehorn 38]

If I need to be very accurate, I measure the diametre of the barrel just under the scope outlet - divide that by half, then do the same with the scope outlet then simply add these first two calculations to the distance (gap) between the bottom of the outlet and top of barrel. Anyway, if you are .2" out it will not affect ballistic charts unless you are stretching your rifle out past 600 yds

[dadioles 68]

Ballistic data charts can sometimes be quite accurate but there is no substitute for spending time in the field shooting at paper.

I love my gadgets and playing with software but have never found anything that matches the trajectory of my own bullets using off the shelf data.

Even when I input my own chronograph measurements the curves still need tweaking.

The only way is to try several makes of ammunition, find the one that shoots through your gun the best, most accurate repeatable groups, then purchase a large quantity of that batch.

Now choose a zero and get everything set up to be spot on. Maybe 50 or 55 yards for .22lr and 100 yards for .17hmr (that is all I have experience of).

Finally shoot a few bullets at targets at exactly measured distances, for rimfire every 10 yards is a good idea. Always aim exactly at the bull and see where the group falls.

Now you know precisely where each bullet will land at every distance and can hold over or under as required.

There is no other way to accurately determine YOUR unique trajectory.