FourBee,
Sometime ago I bought two boxes of Black Hills .223 remanufactured ammo. One box of 55gr SP bullets, and one box of 52gr BTHP match bullets. In my rifle (a Savage model 12) the ammo with 52gr BTHP bullets grouped slightly under 1" at 100 yards. The ammo with 55gr SP bullets produced most groups measuring about 1.5" at 100 yards, some were better slightly over 1".
Note: Some rounds of the 55gr ammo box did not chamber (bolt hard to close). The cases looked too long, so I pulled the bullets from a few cases and measured the length of the cases. They were in fact longer than the 1.760" max for .223. I measured the length of some other cases as best as I could without pulling the bullets for I thought maybe I was stretching the cases when pulling the bullets. Still the cases measured longer than 1.760" as well.
Marc