Long Board Test

[el matador]

I'd say you're plenty close for now. I don't worry much about the scope correction factors. What matters to me is how many clicks it takes to get me to a certain yardage. After finding my load, chronographing it, and zeroing at 200 I put the data into my calc. I then validate my expected drops at 2 different distances (max hunting distance and somewhere a bit closer). Usually its slightly off, so I can play with BC, velocity, and scope correction a bit and usually that makes my ballistic calc line up with the real world.

Your twist rate, muzzle velocity, and altitude will all affect the BC of the bullet. Your chronograph is probably not 100% accurate, and clearly there is some error built into the scope adjustments. If you adjust your parameters in the calc so you're making good hits at your max range then these errors don't matter much. If you're shooting competition you may want to get more scientific about it but for hunting and shooting steel the above method works great for me.

 

[Bravo 4]

Again, el matador has valid points.
I'm just having a hard time considering a $2,000 scope that is showing a variance in adjustments of 4% over 3 Mils as acceptable. If they are off that much throughout (consistently) the range of adjustment then you can make it work, just fudge some numbers here and there. But if the adjustments are unpredictable at best then I say it's a no-go. You are just adding a little error that should be (and could be) corrected. These little errors add up to big errors over distance especially when several compound together, as el matador expressed in his last post.

Last post on this, I promise.

 

[THEIS]

I'm just having a hard time considering a $2,000 scope that is showing a variance in adjustments of 4% over 3 Mils as acceptable. If they are off that much throughout (consistently) the range of adjustment then you can make it work, just fudge some numbers here and there

Hello,
Whew there is no way I would accept that problem...that amount is way past a "variation" for me. It's a full blown FAILURE. I would probably hand deliver it back to someone on executive staff of mfg company. You are paying to NOT have to backwoods engineer your data/numbers.

Have your swapped out that QD mount for fixed mount and see if you have same error variations?
I have never had good luck with QD mount systems.



THEIS

 

[kobraken]

Took my rifle to a competent gunsmith who listened to my issues, what we had done and tried . He had a long board that he uses at his range with all the MILS laid out. He strapped my rifle down, confirmed what we were getting, loosened the mounts that we had torqued to 20"lbs and torqued to 22. Miracle of miracles!!! It now tracks as close to perfect as it gets. To prove his work, he took my rifle to the range and shot it at multiple dial ins and it was right on. Thanks for all the help guys.

 

[SouthTXBowhunter]

What is a "long board test," If you don't mind me asking?

 

[kobraken]

Long Board Test is the process of verifying that your scope is tracking when you dial it up. You take a poster board, a level,(longer the better)and put up your board. Draw a vertical line with the level, and a horizontal at the bottom. Verify your range from target to center of scope (100 yds) shoot the bottom where your lines cross, I do 3 rds to verify zero. Dial in what ever rise you want, I go 3,6,9 mil. Do the math on the expected rise, shoot and see how close you get. There's a calculation involved that you will need to look up for your particular scope (mil or MOA)

As you saw by my original post, I had issues. But with these guys help and some persistence I sorted it out. Hope this answer your question

 

[SouthTXBowhunter]

Long Board Test is the process of verifying that your scope is tracking when you dial it up. You take a poster board, a level,(longer the better)and put up your board. Draw a vertical line with the level, and a horizontal at the bottom. Verify your range from target to center of scope (100 yds) shoot the bottom where your lines cross, I do 3 rds to verify zero. Dial in what ever rise you want, I go 3,6,9 mil. Do the math on the expected rise, shoot and see how close you get. There's a calculation involved that you will need to look up for your particular scope (mil or MOA)

As you saw by my original post, I had issues. But with these guys help and some persistence I sorted it out. Hope this answer your question

Yessir, it explained it really well. Thanks! I use a box test to test tracking but I like the idea of this. I tried googling "long board test" and only came up with this thread, as a result. So I was pretty curious. Thanks again!

 

[kobraken]

No problem. Glad somebody asked something I knew about. There are several really good videos on YouTube that can help as well.

 

[SouthTXBowhunter]

No problem. Glad somebody asked something I knew about. There are several really good videos on YouTube that can help as well.

10-4!

Weird that I didn't get any results on Google. Lol!

 

[velvetant]

Its also called the tall target test, google that and you should find a video from Applied Ballistics by Brian Litz