I have been meaning to write up a post about how I have been testing all of my scopes before I ever mount them on a rifle. Last summer I shot a box test that showed the scope to have quite a bit of error. Although it was highly repeatable, it did not track to an moa scale.
I got to thinking and was going to shoot another test with this rifle as well as all my rifles, and realized at about $1 a shot, I'm going to be spending a lot of money testing out all my scopes, not to mention quite a bit of time driving to the range and time reloading and shooting. And then I still have the fact that there is shooter error, wind and rifle error to add uncertainty to the results.
So I decided to make an affordable test setup to characterize all of my scopes while reducing the source of error.
I did some searching on Amazon and found a picatinny scope base blank for $10 and a rectangular steel tube for $12. I bolted the pic rail to the steel tube with fasteners I bought for $2. Then screwed that to a scrap piece of 2x4. So for about $25 I had everything I needed.
Tools that I already had that are also key to the setup are a yard stick, a 300' carpenters reel tape, a 6ft level, two quick adjust bar clamps, wooden stake and some duct tape. Lots of ways to get this done, my goal was accuracy but also cheap and simple.
putting it all together, I use the two clamps to secure the picatinny rail setup down to a sturdy table. I have used a coffee table, a concrete shooting bench and a large tool chest with good success. The concrete bench is obviously the most secure, but I found is not absolutely necessary.
Then I measure off exactly 47.75 yards (143 feet 3 inches) with the reel tape from the front of the scope and drive a wooden stake into the ground. Then set up the yard stick with the 6' level straight up and down (vertical) secured with duct tape to the wood stake. 143ft 3in is the exact distance where 1 inch on the yard stick is exactly 2 moa. It is also a close enough distance where you can see each 1/4" line on the yard stick, which is why I chose the closer distance. There is also less error in dragging a reel tape to this closer distance than to a full 100 yards.
With the scope mounted onto the picatinny rail, I adjust the elevation turret to the bottom of its travel and then adjust the setup so that the reticle is right on the top edge of the yard stick. Now I simply run the scope through its full range of travel and characterize the performance. If the scope shows error, which most of them do, I will make sure to test the scope over my actual usable range of travel. One of my scopes proved to have more error over the useable range than the entire range.
I also use this opportunity to mount my bubble level to my scope. You can repeat the test for the windage turret by rotating the yard stick to be horizontal. I also fully characterize the reticles as they have proven to have error as well.
One thing this setup does not test is how durable the scope mechanism is under recoil (obviously). But it does provide a very accurate and affordable way to characterize your scope and come up with your scopes elevation and windage correction factors to input into your ballistics solver.
There's different ways to set this up, and you could do it differently than I did if you have different tools in your garage. But I highly encourage anybody to test out your scopes if you plan on dialing to make long range shots or even if you are exclusively using your reticle. Eliminate as much error as possible up front so you can focus on rifle performance once you starts shooting, and have confidence in the repeatability and tracking of your scope.
Here's a couple pics of the setup.
I got to thinking and was going to shoot another test with this rifle as well as all my rifles, and realized at about $1 a shot, I'm going to be spending a lot of money testing out all my scopes, not to mention quite a bit of time driving to the range and time reloading and shooting. And then I still have the fact that there is shooter error, wind and rifle error to add uncertainty to the results.
So I decided to make an affordable test setup to characterize all of my scopes while reducing the source of error.
I did some searching on Amazon and found a picatinny scope base blank for $10 and a rectangular steel tube for $12. I bolted the pic rail to the steel tube with fasteners I bought for $2. Then screwed that to a scrap piece of 2x4. So for about $25 I had everything I needed.
Tools that I already had that are also key to the setup are a yard stick, a 300' carpenters reel tape, a 6ft level, two quick adjust bar clamps, wooden stake and some duct tape. Lots of ways to get this done, my goal was accuracy but also cheap and simple.
putting it all together, I use the two clamps to secure the picatinny rail setup down to a sturdy table. I have used a coffee table, a concrete shooting bench and a large tool chest with good success. The concrete bench is obviously the most secure, but I found is not absolutely necessary.
Then I measure off exactly 47.75 yards (143 feet 3 inches) with the reel tape from the front of the scope and drive a wooden stake into the ground. Then set up the yard stick with the 6' level straight up and down (vertical) secured with duct tape to the wood stake. 143ft 3in is the exact distance where 1 inch on the yard stick is exactly 2 moa. It is also a close enough distance where you can see each 1/4" line on the yard stick, which is why I chose the closer distance. There is also less error in dragging a reel tape to this closer distance than to a full 100 yards.
With the scope mounted onto the picatinny rail, I adjust the elevation turret to the bottom of its travel and then adjust the setup so that the reticle is right on the top edge of the yard stick. Now I simply run the scope through its full range of travel and characterize the performance. If the scope shows error, which most of them do, I will make sure to test the scope over my actual usable range of travel. One of my scopes proved to have more error over the useable range than the entire range.
I also use this opportunity to mount my bubble level to my scope. You can repeat the test for the windage turret by rotating the yard stick to be horizontal. I also fully characterize the reticles as they have proven to have error as well.
One thing this setup does not test is how durable the scope mechanism is under recoil (obviously). But it does provide a very accurate and affordable way to characterize your scope and come up with your scopes elevation and windage correction factors to input into your ballistics solver.
There's different ways to set this up, and you could do it differently than I did if you have different tools in your garage. But I highly encourage anybody to test out your scopes if you plan on dialing to make long range shots or even if you are exclusively using your reticle. Eliminate as much error as possible up front so you can focus on rifle performance once you starts shooting, and have confidence in the repeatability and tracking of your scope.
Here's a couple pics of the setup.
