Spent a bunch of time with a gun on Saturday. Doped out actual trajectories from 10-55 yards with three slightly different scope zeros. Bored enough today that I played with that raw data on Excel a bit and thought it interesting enough of a visual to share here.
Gun is a USFT that average 915fps with JSB 10.34s. Slow twist polygonal rifled barrel.
Scope is a Athlon Midas Tac in MIL.
x axis - distance in yards
y axis - holdover (expressed as 1/10 of a MIL, ie 22 would be 2.2 mils of holdover or 22 clicks if dialing)
Each of the 3 different trajectory curves are produced by a slightly different zero. In theory, the three curves should be identical but simply shifted on the graph. I suspect the reason they're not identical is multifactorial: due to the reticle having mostly 0.5mil increments (0.2mil from 0 to 1mil and 0.5 from 2MIL down) due the less precise nature of holdover (this data was collected using holdover, versus dialing the turret), and simply human error.
The gray has most of the scope zero in the hold UNDER area. Most FT shooters try to avoid hold UNDER, although I've known a couple who could be competitive using hold UNDER.
The blue and red are the more likely candidates for how I typically like to set up a gun/scope. The difference being as subtle as 3 yards for the beginning of the zero distance (22 yards versus 25 yards).
I find a couple things interesting:
In summary, KNOWING you trajectory (and to a lesser extent comparing how that curve falls on the 10-55 yardages with slightly different scope zeros) is crucial to the field target game. And also knowing your scope's strengths and weaknesses allows you to shift the scope zero to capitalize on those strengths and weaknesses.
Spending time setting up an optimal scope zero pays off during matches. Figuring out where pellets are going to go during practice ensures that they'll go where you want them to go during matches.
Gun is a USFT that average 915fps with JSB 10.34s. Slow twist polygonal rifled barrel.
Scope is a Athlon Midas Tac in MIL.
x axis - distance in yards
y axis - holdover (expressed as 1/10 of a MIL, ie 22 would be 2.2 mils of holdover or 22 clicks if dialing)
Each of the 3 different trajectory curves are produced by a slightly different zero. In theory, the three curves should be identical but simply shifted on the graph. I suspect the reason they're not identical is multifactorial: due to the reticle having mostly 0.5mil increments (0.2mil from 0 to 1mil and 0.5 from 2MIL down) due the less precise nature of holdover (this data was collected using holdover, versus dialing the turret), and simply human error.
The gray has most of the scope zero in the hold UNDER area. Most FT shooters try to avoid hold UNDER, although I've known a couple who could be competitive using hold UNDER.
The blue and red are the more likely candidates for how I typically like to set up a gun/scope. The difference being as subtle as 3 yards for the beginning of the zero distance (22 yards versus 25 yards).
I find a couple things interesting:
- All three intersect at nearly 24 yards. So, if a guy was to zero his scope at 24 yards, and shoot at 10 and 55 and then plug that info into strelok, he runs the risk of not being aware of the slight hold UNDERs from 25 to 39-40 yards.
- With this particular scope, ranging to the yard from 20-25 is less repeatable than optimal. This makes the blue configuration the best for me. Because that makes 22-25 yards part of my zero range. If I was to use a scope zero that coincides with the red trajectory, I'd have trouble with the 20-25s because 20 yards is 0.6mils of holdover versus 0.2 mils of holdover with blue. On that same vein, 21 yards with red is 0.4mils of holdover, but 0 mils of holdover with blue.
- (this particular scope is more trustable on determining 45 from 50 from 55 (5yard increments) than it is on determining 1 yard increments from 20-25.)
- A fringe benefit of a initial zero of 22 versus 25 yards (blue versus red) is that my 10 yard holdover is reduced with the blue.
In summary, KNOWING you trajectory (and to a lesser extent comparing how that curve falls on the 10-55 yardages with slightly different scope zeros) is crucial to the field target game. And also knowing your scope's strengths and weaknesses allows you to shift the scope zero to capitalize on those strengths and weaknesses.
Spending time setting up an optimal scope zero pays off during matches. Figuring out where pellets are going to go during practice ensures that they'll go where you want them to go during matches.
