This contribution was originally added to another thread, but i thought it could be of some interest here as we are looking at grouping at 10 metres when shooting with spring powered air rifles (kickers - not recoilless rifles) that are more at home as sporting air rifles and shooting with dome head pellets.
I have spent quite some time testing different types of wadcutter paper punching pellets to see what works best in various springers at 10 meters, and there is no combination of .177 rifle barrel and pellet (that I have found) that can give repeated one hole groups (that is a single hole the same size as the first shot) with any 10 consecutive shots from a spring powered (non recoilless) air rifle at 10 metres.
Some pretty good groupings have been attained (one hole - but greater in size than a single shot) but with the size of the centre 10 spot being so small on the 6 yard Air 7 targets that we shoot this particular 10 metres competition on, it is not possible to guarantee a 10 every time - even if every shot is executed with great repeated precision.
A typical 5 shot target (if shot perfectly in every way) could score 50 ex 50, but this demands some luck.
Another equally well executed 5 shot target could only score 45 ex 50 as the typical best grouping size could easily make every shot a 9 and not a 10.
Any score between 45 and 50 could be scored if the shooter was able to execute five consecutive perfect shots on each target.
Add to this the fact that we are shooting spring powered air rifles (!) and I think it is fair to say that some luck is needed to score a 50 ex 50, and it is highly unlikely that any of us could score 6 "possibles" in a row to give the perfect 300 ex 300.
The fact that some of us have come close to this utopia on occasion I think confirms that we obviously shot very well - but that we also enjoyed some good fortune too!