Hornady Ballistic App Question

[Wellington]

Hey guys, I hope I am in the right thread to ask this. I am using the Hornady app for .22lr PRS style shooting. I am unsure of the B.C. of a .22 bullet, on the web people are saying anywhere from .123 to .19. I am using .13 but the app does not match up with my results. I fill in all the variables before shooting and as far as I can see the only two that could be wrong are the velocity (my chrono says 1065, but it could be wrong) or the B.C. I am assuming it is the B.C. So... if I set up a target at 300 yds and change the B.C. until things line up will the rest of my distances be correct as well?

I am using SK match ammo and seem to be hitting high on all my targets, the further the distance the higher I am. I am thinking adjusting the B.C. up until they match? Thoughts.

 

[55fairlane]

Adjust B.C. until it matches your data or contact both Hornady & SK and see what they say on B.C.

 

[Rob01]

As he said adjust the BC until it's close. Contacting Hornady or SK will be a waste of time as they will give general info which you already have. I use SK Long Range and use .149 for the BC in the Hornady 4Dof program. If you are hitting high with .130 then go up.

 

[Wellington]

Thanks guys!!

 

[Coyotefurharvester]

Make sure your center of bore to sight height is correct.

 

[Rob01]

Yup. Measure from center of bore/bolt to center of windage knob. Works fine. Doesn't matter if 20 moa mount. Get within 1/4" and you will be fine. No math needed as some like to give you this big math problem with half of this and height of this etc. A ruler or calipers will do just fine.

 

[kindabitey]

Hey guys, I hope I am in the right thread to ask this. I am using the Hornady app for .22lr PRS style shooting. I am unsure of the B.C. of a .22 bullet, on the web people are saying anywhere from .123 to .19. I am using .13 but the app does not match up with my results. I fill in all the variables before shooting and as far as I can see the only two that could be wrong are the velocity (my chrono says 1065, but it could be wrong) or the B.C. I am assuming it is the B.C. So... if I set up a target at 300 yds and change the B.C. until things line up will the rest of my distances be correct as well?

I am using SK match ammo and seem to be hitting high on all my targets, the further the distance the higher I am. I am thinking adjusting the B.C. up until they match? Thoughts.

You may need to create an account (it's free) to do this, but when setting up in 4DOF, select variables. Scroll down until you find the 22LR and select something as close to what you are shooting. They don't have SK Match, but there's a couple other SK variants in there. Then verify all the other variables are correct, and
adjust at distance with the Axial Form Factor.

 

[xswanted]

Hey guys, I hope I am in the right thread to ask this. I am using the Hornady app for .22lr PRS style shooting. I am unsure of the B.C. of a .22 bullet, on the web people are saying anywhere from .123 to .19. I am using .13 but the app does not match up with my results. I fill in all the variables before shooting and as far as I can see the only two that could be wrong are the velocity (my chrono says 1065, but it could be wrong) or the B.C. I am assuming it is the B.C. So... if I set up a target at 300 yds and change the B.C. until things line up will the rest of my distances be correct as well?

I am using SK match ammo and seem to be hitting high on all my targets, the further the distance the higher I am. I am thinking adjusting the B.C. up until they match? Thoughts.

For my SK Match I’m using a G7 of .0640

Anytime your using an app for rimfire past 125 or so yards you’re going to have to spend time truing your results.

Shoot at paper or something you can easily see hits.

Shoot and note the elevation you need to hit the target. Do this every 50 yards for as far as you plan to shoot.

Do it again on a different day with different weather.

Then, adjust BC, speed, scope height and other variables until your program matches your data.

It’s the best way to make sure your data matches your setup.

 

[NZ_Fclass]

All the info you need is here:

SK Ballistic table | .22lr ammunition | rimfire ammo | Smallbore

The SK Ballistic table includes all available ballistic data for SK rimfire ammo. BC coefficients can be found in the lower left corner.

sk-ammunition.com

 

[Wellington]

You may need to create an account (it's free) to do this, but when setting up in 4DOF, select variables. Scroll down until you find the 22LR and select something as close to what you are shooting. They don't have SK Match, but there's a couple other SK variants in there. Then verify all the other variables are correct, and
adjust at distance with the Axial Form Factor.

So I got pretty close doing this. Also found out that the temp that you sight in at is important as well, needs to be recorded. I found an almost 1moa swing at 100yds shooting in 90 degree weather. I sighted in at 62 and failed to record it. When I went back into the program I found I had not entered the sight in temp correctly and when I adjusted it I dropped almost a full MOA at one hundred which put me right where I was supposed to be. Thanks to all for your replies.