Since daisy.... was just trying different ammo on a rush basis and using his new 455 for squirrel and NOT for target, he may not have thought about running 10-15 rounds through of each type and then getting a reading at 50 yds. Also, whether he was using a bench rest or sandbags for example and if a windy or a cold day...etc. Set-up, breathing, and trigger pull all have to do with accuracy for each individual. My 4 year old Marlin 39a, w 2lb 8oz trigger, does better at 60 and 70 meters off sandbags with HV ammo as my original first rifle used for target shooting.
My new LH .22LR, 452 American with factory 2lb 7oz trigger, designed for subsonic target, should surely do better when we get outdoors for real target shooting with the right condtions. I would take daisy's results under scrutiny at this time. Some other forums might have complete results from actual target shooters on their 455's?
It is always nice to have people post what their results, but need to have specifics of how they tested....etc. The ocassional shooter will not do as well as the weekly competitor shooter using mechanical benchrest holders or off SB, which we have to keep in mind.