Nice shooting. You are almost there.
Try seating the bullets deeper to tighten up the group. Go .005" and .010". I'd bet one of those would do it for you.
JD338
A new build is fun and very rewarding. I think the first step is to clearly be fine the purpose of the rifle. From there caliber, action, barrel contour and length, and then the stock. Keeping in mind the total weight.
JD338