338-378 wby mag?

[shortkut]

Hey guys! We sighted in our new 338-378 wby mag on sunday! We sighted in 3" high at 100yrds, and to my suprise it was still 3" high at 300yrds??? That is not what all the Data says it should be?

Any input?

Thanks

[elkhunter11]

How large were the groups at 300 yards?How many shots?

[Solothurn]

Originally Posted by shortkut

Hey guys! We sighted in our new 338-378 wby mag on sunday! We sighted in 3" high at 100yrds, and to my suprise it was still 3" high at 300yrds??? That is not what all the Data says it should be?

Any input?

Thanks

Could it be that you have a large objective lens on your scope, requiring that the scope be mounted fairly high off the rifle??
If so what you are encountering is your line of sight is transecting the trajectory at a higher point in the trajectory than what most data allows for.
Your line of sight is perfectly staright, but your rifle is pointed slightly upwards under normal circumstances. With a scope mounted higher above the bore the intersection is exagerated and this will cause exactly what you are experiencing. No big deal just resight to zero at 100 and no hold over is required until 300 yards.

[shortkut]

I have used a Leupold VX3 4.5-14x40 B+C with low rings! I tried to keep it as low to the line of site as possible.

As for the groups I would be lying if I said they were much more than 2" @ 300. With that said Dad shot the best group! Dad's group was really nice, but he pulled the last shot that opened it up. At 100 all shots were touching! I seemed to be pulling consistantly to the left, with that said I sighted in two other rifles prior to big bertha!

[Solothurn]

Well given the small objective and low mounts my suggestion from my own experience does not fit your bill.
Any chance your mounts are not flat?
Ie the rear mount being higher than the front?
Are you using the Burris rings with the inserts? Any chance the rear inset is plus 10 or 15 moa and the front inserts are zero moa?
After that ya got me. I am out of ideas.

[shortkut]

I used standard leupold bases and rings as that was what was handy. I need to load up some more ammo and I will take it back out to the range for more testing.

[joshman12]

Originally Posted by shortkut

Hey guys! We sighted in our new 338-378 wby mag on sunday! We sighted in 3" high at 100yrds, and to my suprise it was still 3" high at 300yrds??? That is not what all the Data says it should be?

Any input?

Thanks

i would rero it in at 100 yards





vegitarian: means bad hunter

[elkhunter11]

i would rero it in at 100 yards

Why?

[209x50]

Originally Posted by elkhunter11

Why?

I would sure find the apex of the arc anyway.

[PoppaW]

sounds just right for long range. But I would shoot more to figure out the 200 and 500 trajectory. Really shooting gives some bizarre results sometimes.

[panwojciech]

The B&C reticle has been design with different points of aim for different distances. If you zero on 100 yards (in your case 3 “high) and you go to 300 yards target aiming with your 300 yard bar you should hit 3 “high. Just a suggestion…

[elkhunter11]

The B&C reticle has been design with different points of aim for different distances. If you zero on 100 yards (in your case 3 “high) and you go to 300 yards target aiming with your 300 yard bar you should hit 3 “high. Just a suggestion…

I assumed that he was using the same crosshairs for all of his shooting in order to test the actual trajectory of his load.If he used different aiming points on the reticle for the various distances,he really does not know the trajectory of the load at all.Reticles such as the B&C only work properly with cartridges with a certain trajectory,so unless your loads trajectory matches the one used to calibrate the reticle,the reticle will not be accurate at longer ranges.

[shortkut]

Originally Posted by elkhunter11

I assumed that he was using the same crosshairs for all of his shooting in order to test the actual trajectory of his load.If he used different aiming points on the reticle for the various distances,he really does not know the trajectory of the load at all.Reticles such as the B&C only work properly with cartridges with a certain trajectory,so unless your loads trajectory matches the one used to calibrate the reticle,the reticle will not be accurate at longer ranges.

I did use the same cross hair! it was the center (main) I did not try the others!