I've been playing with a Ruger Model 77, an old tang-safety rifle, built in 1971. The rifle is in .25-06 and I've been piddling with loads. Several years ago I put together a load using Reloder 22 and the Sierra Gameking bullet. I've shot it in my son's rifle and it shows good accuracy, under an inch, so I loaded some of those for my rifle and took it to the range.
That Gameking load is a proven load in two rifles, it's always shot under an inch in either of the two. However, that bug-hole group with the Hornady bullets has my eyes open. It might be worth it to load another dozen or so and see if that group is an anomaly, or if it will continue to be a good load.