With very little firearm experience (limited only to the M-16, SigSauer and Beretta service models) and with a still fledgling PCP know-how, let me think out loudly. With all other variables eliminated (weather, wind, shooter error, barrel quality, proper rifling twist, proper velocity for the pellet/bullet type), I think that the accuracy/consistency between firearms and airguns at moderate distances (let's say 100 yards) comes down the consistency of the power plant that is behind the bullet/pellet and the physical consistency of the bullet/pellet itself.
I do not know how much consistency (fps variation) can be achieved with proper loading of bullet cartridges, but with airguns a maximum variation of 10 fps can be achieved from shot to shot. Using two identical JSB 18gr pellets with the same head size, weight, shape will result in about a 0.1 in POI variation at 100 yards. So almost negligible. This is in theory a single-hole shot...if all other variables are eliminated. If a firearm bullet can be launched at the same 10fps variation difference propelling it, the POI results should be the same.
But, the major difference between a pellet and a bullet is the BC that comes mainly from their different shapes. The .22LR firearm bullets seem to have a much larger BC on average (around 0.1 vs.the JSB 18gr 0.030 example), so the POI is actually much smaller at the same distance at the same velocities. Also, the firearm bullet has a more aerodynamic shape (thus the 3 times higher BC ) so the imperfections of its physical shape may not affect the stability and consistency of its flight as much the same physical inconsistencies would affect an airgun pellet. An airgun pellet thus is much much more dependent on having a more uniform shape for a consistently stable flight.
At the end, if all other variables (which by the way can be controlled in theory) are equal and eliminated, the POI difference at 100 yards for airguns is about 0.1 and almost immeasurable for bullets. It seems that one can shoot in theory single-hole at 100 yards with both airguns and firearms.... So the question is: why is it so hard to score half inch at 100 yards? Is the pellet the cause....or the combination of the rest of the stuff which adds that extra 1 to 2 inches of POI change in a theoretically single-hole equation ?
Where am I going wrong?
