Custom BDC Knob

Target tape and sharpie, two years old and going strong, lol!

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you and Jason should market these

They do work, but only are consistent in the environmental conditions they were set up in, and from about 300-400 yards and in.

For example, I loaded some full custom ammo for a customer's 6.5x284 rifle. The rifle was also a high end rifle. So, the rifle and ammo were perfectly tuned together. He bought a high end scope and bought a "custom" BDC turret for it. The BDC turret had been "programmed" for certain environmental shooting conditions. My customer called me up and was mad as all get out, since he shot a 1.5" group at 500 yards, but it was exactly 11" low. He was mad that it was low. I said ok, let's run the trajectory numbers. He told me the conditions that the BDC turret was set up for. I then ran the trajectory data with the EXACT shooting conditions he was currently shooting in. I calculated 10.2" low for his current shooting conditions from where his BDC was set up for. He then understood why I don't recommend the BDC turrets.

My point is, you have a high end system- rifle, ammo, scope and shooter, and you induce a large error factor into the "system" with a BDC turret. The BDC turret is your weakest link in the system. If it is used within it's limits, it should work. If you learned moa or mils, it would solve the entire problem, and you would improve your "system" to other rifles also. Learning a BDC only applies to the rifle alone. LEarn mils or moa, and you can carry this knowledge over to all your other rifles and calibers. I have instructed and had customers take shooting classes, and when they learn the mils or moa system, they have what I call the "Ah Ha" moment. And EVERY single shooter tells me they don't know why they did it the other way and mils/moa is so much better.

I've got a few years of recording environmental data prior to shooting down my range. Given the span of Density Altitude of -300' to +3300', and a temperature fluxuation of 20°F to 105°F I can plot what each load is doing in its' respective rifle, and look for variations. What my conclusions are 6.5 Creedmoor, and 7mm-08, are relaible, in all weather, out to 500 yards. Beyond 500 yards .1 Mil may have to be added or taken away depending on temperature and DA. Therefore I will label turrets like this out to 500 yards.

The more the hot-rod of a cartridge and load, the farther the corrections stay put. So 7 Rem Mag tends to hold up, in all weather, at my range, to 600-700 yards. But I know that when I take that rifle west, the DA will rise, And I need to bump down my corretions, but only slightly. And of course, I'm using Mils.

While not ideal, this method works pretty good for me in the conditions I typically shoot in. I primarily use this set up for 3-gun matches inside 500 yards. Most of the targets beyond 300 are full size IPSC steel so if there is much deviation (weather, up/down hill, etc..) I simply "hold off" for correction. It isn't precise but it is precise enough for what I use it for. Hopefully one day I can get set up for long range and learn how to calculate and correct properly.

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