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An Idea
Guys:
Pole vaulting over mouse turds a bit.
One of my guys took my neat little target I shot showing trajectory given a 300yard zero so he could show his Joes but when the weather breaks some, I will shoot another one and photograph it. I will say this much with any modern certerfire cartridge today -- your ordinate will be between five and eight inches for a 300 zero.
I honestly don't get real hung up over this type of thing. If anyone is so interested in finding out a precise close range zero my advice is to zero your rifle up at the range you want to shoot -- 100, 200, 300 -- could even be 500yards or meters. When you have a good zero at what ever range you want your battlesight zero, draw a round black dot about two inches in diameter on a piece of paper and put that target at what ever you desire for a short range. Then shoot a group and measure the distance between the group and the middle of the dot. The closer the target, the more anal you absolutely must be in your measurements. Remember that ther are four minutes to an inch at 25 meters so you must be anal in your measurement. Also, I do not trust any ballistic program to give me a close, close range zero. They are not refined enough to give you a good close range zero.
I once had some Hooaas make their own 'Thermometer' targets for their individual M-24 and SR-25 rifles. After a number of days on a KD range I decided they were consistent enough in their zeros to have them make their own Thermometer targets and that is what we did using 25 yards as a short range. I had them shoot a 100, 300, 500, 600, and 800 elevation to mark the thermometer targets for the short range zeros. I took the targets home and measured the heights of each group using a micrometer to be as perfect as possible. Then I used my computer to make each of the Hooaa snipers a thermometer target representing his individual M-24 and SR-25. There were differences between rifles and shooters. I have the averages somewhere
If you go through this process to make your own thermometer target, and want to use the same target for a close range zero, ensure you use a plum of some sort when you staple it to a target frame. The vertical line must be verticle as you are not only adjusting for elevation but windage as well. The target must be straight up and down. And, you can not compromise over your zero. It must be absolutely perfect in terms of hitting its respective range index. The biggest problem with these reduced targets is that most shooters have not trained their eyes to see what is and what isn't perfect. So they accept groups that are slightly off and that equates to big time errors at longer ranges.
Enough targetology for one day I think.
Gene
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