G7 BR2 Curve error

[Sika Slayer]

I was using my G7 on the range the other day, caliber was .284 AI, speed Approx 2830 fps, projectile 162 g A Max.
0 was set at 200 yards, at 300 yards it was grouping about 2 inches low but at 500 yards it was 1.5 inches high.
If I adjust the speed so it matches at one of the ranges the other ranges error increases. I have tried G7 and G1 calculations.
Is there anything else I can do.

 

[kcebcj]

I'm no expert but in my experience you only have four adjustments. The zero entered has to be exact along with the measurements at the range you are shooting. The scope has to be proven to have accurate come-ups. The velocity input needs to be correct. The bullets BC input needs to be correct. If those things are correct then it's system failure. The rifle, the load, or you the shooter.

Of course all this testing on a still day on a level range or with incline adjustment.

 

[IAHNTR]

Make sure the BC is correct. Might be slightly different than what is advertised by the factory. Also, you need the correct velocity.

I made the mistake on a smokeless muzzleloader once and used the bullet manufactures BC. Big mistake.

 

[Sika Slayer]

I have tried adjusting the B.C and the velocity so that the point of impact is correct say at 500 yards but at 300 yards the error increases and point of impact becomes even lower. I have a new VX6 3-18 on the rifle.

 

[kcebcj]

Ran your load in QuickLoad using the AMax and the same velocity and generated these come-ups with a 200 yard zero. Do these come-ups at 300 and 500 match somewhat close to what you have? Remember the zero has to be dead nut's...perfect!!!

Which scope are you using? There are a lot of things that could be haywire but the above bullet path is probably pretty close to accurate with that bullet and velocity.

 

[Rich Coyle]

I was using my G7 on the range the other day, caliber was .284 AI, speed Approx 2830 fps, projectile 162 g A Max.
0 was set at 200 yards, at 300 yards it was grouping about 2 inches low but at 500 yards it was 1.5 inches high.
If I adjust the speed so it matches at one of the ranges the other ranges error increases. I have tried G7 and G1 calculations.
Is there anything else I can do.

I discovered the height of the rings can influence apparent trajectory.

 

[sp6x6]

In JBL you can set your scope height

 

[Sika Slayer]

My scope is 1.9 inches high, I have put this into the G7 BR2.

 

[Sika Slayer]

Ran your load in QuickLoad using the AMax and the same velocity and generated these come-ups with a 200 yard zero. Do these come-ups at 300 and 500 match somewhat close to what you have? Remember the zero has to be dead nut's...perfect!!!

Which scope are you using? There are a lot of things that could be haywire but the above bullet path is probably pretty close to accurate with that bullet and velocity.

View attachment 56586

No its not the same, the point of impact was 2 inches low at 300 yards and 1 1/2 inches high at 500 yards after I adjusted the scope to what the range finder told me to adjust, 2 M.O.A up for the 300 yard range and 7.5 M.O.A up for the 500 yard range

 

[turkeyfever]

Maybe this will help
https://youtu.be/gQ4WeB9ytXw?list=UU1xRShQSnBGtHy9bHOC00Fw