Not bad for a beginner, not bad at all. If you are shooting from a bench, make yourself a lazy L stand out of 2x6 to hold the gun and support the butt. Pad the bottom and make a V notch in the leg top, put leather inside the notch stapled to each side. This will help stabalize a handgun for shooting groups when doing load development.
If you know how to shoot Creedmore, the position is very stable with a center grip bolt-gun. Some say better than the bench.
It appears that not all of your holes are round, could be the light or the photo. If you have some round and some slightly oblong holes, you may be at the edge of the twist rate's ability to stabalize the bullet. Of course if the 154 is a BT, at 60 yards it will not be 100% stable quite yet.
Suggest you find the 130 Speer flat base and put them over 29 grains of WW-748 powder. The dime will cover the group with the 130. The load does not just shoot sometimes, every gun I have ever owned shot the load. It is one of those rare loads that you can actually feel the accuracy as you shoot, it is as if you can not miss.
Also, change your target to a solid black square 1.5x1.5 inches and use the corners to match the corners formed by the crosshairs. Allow just a hair of light between square and crosshair. This stops canting and returns the cross hairs returning to exactly the same point. Your groups will be cut by 1/4.
You might try this site to find out about a rear grip stock. No doubt you can change the trigger to a rear grip configuration (standard rifle) if the parts are still available. I suspect that you have a Sako AI or Vixen action.
Practice, practice, practice.