I had a chrony to hand yesterday and checked a few rifles.
My sons 223 Remmy with quite new 20" sporter barrel produced the following. Only two shots of each. (ammo is scarce here)
American Eagle 50gr HP 3111 3172fps
Hornady Spire 55gr (SP) 3047-3050
Fiocchi 50gr V-Max 2939-2956
Astonishing how much they differ.
Would any one know whereabouts the speed should be for a 22cal BSA Meteor springer ? I measured 491 - 506 fps with mine.