Hi Michael, this is reliable with a variety of ammo. One test reports - "There were no anomalies or malfunctions with any of the cartridge types used in the test. Case ejection was always powerful and the angle was almost always the same. Despite the low weight of the gun, recoil was absolutely acceptable even with HV ammunition."
There is no 'Best' ammo to use. Try a variety and see what works best for you.
I've had good luck with Thunderbolt ammo at about half the price of CCI's budsgunshop.com/product_info.php/products_id/159920/remington+22+thunderbolt+rimfire+ammunition+.22+lr+40gr+1255+fps+525+ct ,
Stay safe & have a great day!

Hi Michael and welcome. This should be reliable after a 50rd or so break in period. I would recommend the tried and true CCI loads: budsgunshop.com/product_info.php/products_id/63200/cci+.22+lr+40+gr+mini+mag+round+nose+0030+100+round+box -------------------------------------------- budsgunshop.com/product_info.php/products_id/63201/cci+mini+mag+.22lr+36gr+copper+plated+hollow+point+100ct+0031 ---------- Cheers and stay safe!