A gentle suggestion for all .22lr rifle owner. Especially for rifles made by Brno/CZ. Avoid using metal cleaning rods to brush the bores. The metal rod tends to hit against the ejector stud situated at the bottom of bolt channel in the receiver tube when cleaning from breech end and eventually wears it off causing ejection problems on the longer run. Remedy? Remove the ejector plate, weld, reshape or replace it with a new one if it can be brought or imported. Easier way to avoid all these problems is to use PULL THROUGH stuff like BORE SNAKE etc.
Happy shooting
Marksman