In-Validada: Who's Zoomin' Whom?

[AZRickD]

I just got back from my 300 yard rifle clinic which is designed to trouble-shoot and get the bugs out of the rifles, etc.

I had enough time to shoot at 100 (zero), 150, 200, 250 and 300 yards to begin my data book with my 168g Nosler J4s moving at 2,750fps.

I found that my rifle was spot on, with my bullet drops approximately matching what I had expected via ballistic tables. With that done, I decided to work the dials on my IOR-Valdada 2.5-10x42 scope to test the clicks on the turrets and the magnification.

I spun it up in one-moa (two-click) increments at 100 yards and took a shot from 0-moa to 5 moa. Then to 10 moa, 15 and 20 moa (until I ran out of paper) and then returned to zero.

The rifle returned to zero perfectly (same hole). The moa clicks were pretty good, within accuracy error, from 1 to 5 moa and getting just short of expected at 15 and 20 moa worth of clicks.

I didn't have time to do both left and right clicks so I only did right. Five moa worth of clicks only brought the point of impact 3.8 inches to the right (one shot, no groups). 10 moa brought the impact over just 8.3 inches. I'd have to do more shooting to see what was up with that but I didn't have time today.

Next I did the zoom test. Again, at 100 yards, I shot a three-shot group at 10x, then shot a three-shot group at 2.5x. The 10x was centered, yet the 2.5x group impacted two-inches left and a half-inch high. I reset and did it again. Same results.

This is a deal-breaker. I'll have to return the scope to IOR for replacement.

Bummer, since I had put a lot of time into it. Dang good thing I didn't paint the scope.

Rick

 

[AZRickD]

I called the guy at IOR today to tell him that my scope was on the way. I told him what was the deal and he said that for a zoom that goes from 2.5-10x (a 4x increase, vs a 3-9x -- 3x increase), this is considered par. He said that the POI should be consistant from 10x down to 4x, where it start to deviate due to paralax. His point was that since the 2.5x would be used to shoot at very close range, say, under 50 yards, it would mean a shot that would be in the "kill zone" regardless.

He said he would take a look at the scope. He offered to give me the latest upgrade but found that my scope (dated 12/2003) was the latest version.

Rick

 

[Beetle Bailey]

Thanks for the post. I was thinking of getting one of the fixed power scopes but am still interested in how this turns out. Keep us updated.

 

[Grump]

That's a lot of parallax for 100-yard testing. If it truly is, I believe you should be able to replicate it and manipulate it by shooting 3 shots with your eye way left, and another 3 shots with your eye way right, from the centerline of your ocular lens.

If it truly is parallax, you can just choose what range will have the error. Others more familiar with the topic can advise you of your options.

I strongly suspect, however, that there is a more fundamental error in the optics. Testing a different unit *may* reveal whether it is a design defect or a specimen defect.

 

[AZRickD]

IOR in Littleton, CO should have the scope by tomorrow. My hope is that I get sent another scope.

Rick