Parallax error on Leupold VXI vs. VXII

[biederboat]

Before I contact Leupold on this, I'm betting that there's some Ifishers with some experience here. Weapon: 300 Win Mag shooting 180 Nos w/ Reloader 22, 75.5 gr. The ammo has stayed constant throughout this process. With a VXII 3 x 9 (not AO model), I got about 1.5" high at 100 yd, even at 200, -2" at 300. Switch to a VXI 4 x 12 and I get 1.5" at 100, -2 at 200 and about -9 at 300!! To make the question as simple as possible, could the scope change cause that much error? Again, everything else, except maybe temperature and air conditions were the same.

Thanks,
Biederboat

[the4thshake]

Were the two scopes mounted the same distance above the bore? Different heights would cause a different trajectory.

[biederboat]

Originally Posted by the4thshake

Were the two scopes mounted the same distance above the bore? Different heights would cause a different trajectory.

Same mounts, just had to remove the upper caps on the mounts.

Biederboat

[Channel rat]

It looks to me like the trajectory with the second scope looks correct. Assuming your getting 3000 fps at the muzzle you should be zeroed at 200 yards and about 6.5 inches low at 300 yards. The website-JBM small arms ballistics is very usefull for giving you an idea of how a load should perform.

[biederboat]

Originally Posted by Channel rat

It looks to me like the trajectory with the second scope looks correct. Assuming your getting 3000 fps at the muzzle you should be zeroed at 200 yards and about 6.5 inches low at 300 yards. The website-JBM small arms ballistics is very usefull for giving you an idea of how a load should perform.

I'll take your word for it, I'm sure some of this is due to my inexperience and relying on "field data" when the physics don't lie. I plan on going back to the range this week to see if I can duplicate (or correct) the results.

Thanks,
Biederboat