my old 521 T bolt with lyman peep sights love the federal champion 525. my ruger 22-45 mark3 as well,while i get nothing but troubles with winchester 333 or 555...something related to this specific hollow point profile and COAL. my 521T goes sub moa with eley standard and federal match at 50 all day long.....i must admit that i'm quite sold to the federal champion because it prooved accurate in most 22 i've shot to this day. M-22's are the only winchester accurate enough for me.when i can't get federal ,i content myself with M-22's. yes i'm cheap when it comes to 22 ammo.