Originally Posted by Brian.Samson
The rule of 15's is ballistically correct, but.... you might find your pellet doesn't hit where ballistics says it should - and that'll be down to your screw up, not gravity.
I read it all Bri and enjoyed it thanks. Call that a long post ... Pah!
The bold bit is what I've being trying to explain to Verminator.
I'm not trying to insult him and suggest he can't shoot.
Try and forget Rifleman's, Gravity and all that stuff for a second. Even forget cant and PA error because he says that he focuses the PA at each range.
Even using a dead pcp top shooters spend an eternity trying to master trigger control. They are trying to get the trigger to pull straight back. They are trying to complete the trigger release with no movement applied to the rifle. That's not easy to do. To move that trigger finger you have to move tendons and muscles in your forearm. I've looked through a scope and tried to hold the cross perfectly still on a point and pull the trigger back, without the rifle cocked, and it's not easy to do. There's also the issue of predicting the shot and snatching. I know I've done this because at a comp, under the excitement, I've many times forgotten to take the safety off. So when I pull the trigger back, expecting the boom boom stick to go bang ( I've done this with pcps and springers ) the cross hairs fly off the aim point but the rifle doesn't fire. So I did a lot of work on that.
I was , surprisingly, getting decent scores whilst still doing that.
I reckon that if you took one accurate pcp/pellet and asked one good shooter to zero that at a target at a certain distance, and then asked another good shooter to also shoot groups at that range, the groups should both be pretty good but the poi's may be different. That's because each shooter will release the shot differently. That's with a dead pcp and the scope focussed at that distance.
I also reckon that if you then keep that target at that same distance, but make it elevated, the chances are that each shooters poi's will change ... and probably not change by the same amount or in the same direction. That may not be because of Rifleman's, Airgunner's, Gravity or rubber barrels. It may be because the change in body position means that the slight movements in each shooter's forearms whilst releasing the trigger and any other differences in body tension etc are different now at this new angle.
Verminator seems to be believing that because it's a pcp and because the PA is set at each distance then that rifle will keep putting pellets in the same place, everytime, so any change in poi must be because of something like a bendy barrel. I'm saying it's more than likely that there may be slight changes in poi due to elevation/gravity at certain longer distances and more acute angles ... but there is likely to be just as much, or even more, change in poi because of the person pulling the trigger ( even if they can shoot ).
Verminator could maybe try this. If two people that can shoot are using the same pcp and setting the PA then, by his theory, that rifle should just keep putting the pellets in the same place no matter who shoots it. So try it with a couple of mates that can shoot. You zero the rifle at a set distance. Shoot a couple of groups. Then elevate the target and shoot some more groups. Then get another decent shooter to shoot at level and elevated targets ( paper ). See if the poi's are all exactly the same for all shooters. See if any change in poi on the elvated targets has changed consistently from shooter to shooter.
The rifle, PA, gravity, Rifleman's, Airgunner's, Bendy Barrelitis have all remained constant. The only change is the shooter. So if the shooters can all 'shoot' then the poi's should all be exactly the same. If they aren't, or the changes in the elevation shots aren't consistent, then it proves that even using a pcp and setting the PA that shooting in an elevated position can cause a shooter to get a change in poi.