Thu Jan 21, 2016 6:26 pm
I find that it has a lot to do with your ability of knowing your rifle and your ability at grouping well, no matter what calibre you use. After this, its actually knowing your range to the target. This is where people can come unstuck. Different backgrounds to the target can make it easier, or harder to judge your distance to the target. If you are shooting along a farmers fence line with evenly separated fence posts to your target, then that can be a big help, but out on featureless open ground, it can be a lot harder. Its best if you have invested in a range finder to help with the process, especially as the arc of shot is more pronounced in .22 and .25, making aiming points different. I spent 12 years in the Army and the rule was that several people could guess a distance to a target, but all come up with a slightly different answer, so the average was the distance to shoot at. Also a military rifle is more forgiving with only around a 2 inch drop every hundred metres out to 600 metres. We used to aim 4 inches above our aim point at a 100 metres zero, with our sights set at 300 metres. 300 metres was the average battle range, so you knew that a shot at the body centre mass at these ranges were going to do the job, even if you were slightly out. Air rifles being a lot less powerful mean that they aren't as forgiving if you get your distances wrong.
I spent hours with my Webley LiteW8 on the range, testing my .22 calibre from 15 to 55 yards at 5 yard increments, so that I knew the aim off points with my mil dot scope. I then did this with about four or five different brands of pellet, of which all were slightly different in result, as lighter pellets travelled faster and didn't need as much aim off. Once you make up a range card, and go into the field with your range finder, its just a matter of checking the range to the target, and looking at your range card. You can also check ranges with a range finder at different points over your field of target area before you shoot, which is also helpful. If you do this, it matters not, which calibre you use, .177 .20 .22 or .25. The biggest problem after this is windage, as even a small breeze can alter the shot, especially the further out you are to the target. I came to the conclusion that in windy conditions, where you can get cross winds at various ranges to the target, that it wasn't worth the risk of shooting squirrel, rabbit, pigeon etc, as there is a much higher risk of injury, rather than a clean kill. FAC rated rifles, are probably more forgiving, as they travel at higher speeds, and can make use of the larger calibres extra energy, with the benefit of higher muzzle velocities.