Ysterhout Dot Net
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... or seven steps to happiness from far.
I started out wanting to shoot long range, but I had no-one to mentor me. Watching the content posted by many people, it seemed straightforward - get an accurate rifle with a good scope, find a good load, and use a ballistic calculator. I quickly realised that there is critical information missing, that is not readily available. The various information sources each provide one piece of the puzzle, and some pieces are missing altogether.
This write-up is based on the path I had to follow, and perhaps you can identify with some of the issues, and take something useful from here to apply to your firing solution.
Because there are multiple elements comprising the firing solution, each element will be covered individually. Any problem encountered on the range with the firing solution can always be traced back to one of more of these individual elements.
Paying attention to the following seven points will give you a good basis for achieving repeatable accuracy at long range.
The first element of the firing solution is the rifle itself, or the platform. Important parameters that you have control over are
Specific off the shelf rifle solutions will have those three parameters pre-set, with no additional work required. When a general hunting rifle, or custom barrelled action is used as basis for Long Range, these elements require careful attention.
It is assumed that the rifle parts are assembled correctly, that the chamber is properly cut, and all the parts are free from defect.
I mention this, because I have personally seen a high end, factory competition ready rifle with a chamber 20 thousands out of round. Don't assume your rifle is perfect because it's new, or because it was expensive. Check everything, or have it checked for you. It's a small price to pay for what could be months of shooting with a problem you can't identify.
I once asked a gunsmith to fit a 20 MOA to my Remington Long Action. Every 20 or so rounds, I had to tighten the rail screws. I tried bedding the rail, it didn't help. Finally I removed the rail and inspected it more carefully. It was in fact a straight rail, with the front cut down to simulate a 20 MOA rail. Fortunately when I explained that what was on the rifle is not what I ordered, I was given the correct rail. For some reason, a mistake was made, and thankfully, graciously corrected.
The point is that you do not accept that the hardware is good without physically checking.
Problems in the platform hardware can easily negate a perfect load, perfect scope tracking and perfect trajectory predictions.
You want the lowest shot to shot velocity variation. A good load will hold to single digit shot to shot velocity variation.
Also known as the box test, do this first before the tall target test.
This shows that the scope will not change windage when adjusted for elevation, and will not change elevation when adjusted for windage. There is a video on Youtube by Ryan Cleckner demonstrating a scope tracking drill. Ryan has inadvertantly proven that although his scope is tracking repeatably, it is not tracking true. The scope introduces an elevation change when changing windage. There is either a problem with the scope itself, or the scope is angled in the rings. If the scope is just angled in the rings, aligning the crosshair to the bore will fix it.
When you do that test, and the holes describe a parallelogram, not a square, it indicates a problem. In one of my tracking tests, the scope introduced a windage change with a change in elevation. It was faulty, could not be repaired, and replaced by the manufacturer.
Verify your scope tracking correction factor. Very few scopes track true. If you find yourself adjusting the BC on your calculator to match observed drop, you probably omitted this test.
Everyone knows how to zero a scope, but what you are not told is that the exact distance of the zero target to the muzzle is very important for the ballistic calculator. As is the actual scope height.
Verify that the drop chart is true on at least two widely seperate distances on the trajectory curve.
This will show you if the BC number on the box is the BC you are getting from your rifle, under your conditions. With the test described on the Debugging page, I verified that 300 grain .375 Peregrine Glidemaster monolithics BC is as advertised in my rifle, and the 123 grain Lapua Scenar measured 22% less than advertised.
You should do this test if you find that you need to change your bullet BC in your calculator to true the data.
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