Yeah, MOST are missing that the OP specified 55gr __FMJ___!
I've had one lot# of Federal/Lake City 55gr FMJ's (component bullets) that will consistently shoot under 1.25". These will typically shoot 3-4 at around .5", with 1-2 shots opening up the group. Excellent "plinkers" which is what I bought them for. I've got a quantity of Remington 55gr flat base FMJ, but they are more typical at 1.5-1.7" 5-shot groups.
Sierra makes a 55gr FMJ that will shoot under 1-MOA, but they are the same price as a 55gr GameKing BTSPT that will outshoot your rifle, so what's the point?
For what it's worth, for under 300yd shooting, a flat base bullet will be more accurate than a boat-tail, everything else, the same.
It's when wind drift starts to factor in that the boat-tail bullets gain the advantage with the higher b.c. reducing time of flight, and therefore wind drift.
If you want an accurate inexpensive 55gr bullet, get some Nosler Varmageddon 55gr JHP, or MidSouth 55gr JHP Varmint Nightmare, or MidwayUSA 55 JHP Dogtown bullets. 1/2" or better accuracy at $0.13 or less.
Hint, buy in bulk, and save 3-5cents each...