I was refering only to lead balls, not the undersize steel BB's. The Beeman perfect rounds that I have mic around .176 on average, and I think that the perfect round moniker is not deserved. Perfect and round they are not, and you are right, being undersize they do not seal the bore. As stated , I have only found one of my .177 springers and pumpers that will take them, all the others will let them fall through the barrel. I've only shot them in the QB-57 at 10 meters. I tried them in that gun, but I would be afraid of damage from such a loose fit in one of my good springers . What got me thinking was the review in Shotgun News of the Shark pump gun and the Lobo .22 round balls it used. The groups reported were impressive for the gun. I was wondering if anyone had some of the .22 Lobo's, and if they had used any in other guns? Particularily the pneumatics or the CO2 guns? I wonder what size they really are? They are the only.22 can rounds available that I know of. The H&N 's aren't available in .22 now, to my knowledge . As to the effective ness of the round projectiles. I have shot small game using .310 dia round ball in reduced loads in various 30 cal rifles . It has been my experience that they do quite well on game, and are quite accurate within 50 yards. I also notice that there were a few posts on some of the other forums where other's have used the .25 cal Beeman perfect rounds in the Webley Patriot for squirrels with very good results. Also had an uncle who would take the lead BB's and wrap two in a small piece of tissue and load them in his old .177 pumper and shoot pidegons with them. Worked good.