Honestly, too many people agonize over tiny groups or the lack thereof. Your rifle is certainly a more realistic example of what many rifles are capable of. Improvement is very likely too, but when you see so many small groups posted, I wonder what group of how many most people post to show the rifle's real accuracy.
I had a 1949 270 and it shot very well. I sighted it in and put the crosshair on the center of the group and shot lots of critters with it. I now have a pre-war carbine in 270 with a 2-4 scope on it and I don't worry about groups, but I can tell you there isn't any animal within 300 yards that won't be killed instantly with that rifle and 130 grain bullets...