My question is this: should I suspect my bedding job is the culprit,
Without reading all the other replies, I would say possibly.
I would start out with the simple and cheap. Dismount your scope, pull the bases off of the action, and clean everything really thoroughly, then reinstall the scope.
Change ammo. Monolithic bullets like Barnes can be fussy. I've owned over 200 rifles in my life and worked with them extensively. I have owned ONE so far that did best accuracy work with Barnes bullets. It is not a good track record. I would try something with a flat base like plain ol' Remington 180 grain CoreLokt and Federal's 168 grain match load .. not that you will hunt with them in the end, but to validate the gun's potential.
You describe yourself as a lifelong shooter so I assume you have other scopes. My next suggestion, if the first doesn't fix it, is to install a different scope on that rifle. Even new scopes can be "bad". A scope with something loose inside can shift between two "fixed" points creating double-grouping. (I have a "spare" scope which is well proven to install on rifles as a sanity check when things are behaving in inexplicable ways.)
Then look at the stock. I save that for last-ish because it's more complicated and potentially more expensive. Having a barrel almost free floated enough will produce the groups your pictures show. When free floating a barrel, I want it FREE FLOATED, not almost, but by a solid margin. Take a stack of 10 $1 bills and see if the stack will slide between barrel and stock ... and how far, and whether it is balanced on both sides or indicates the gap is closer on one side than on the other. Stocks flex more than we realize during recoil. It is ok to have contact under thick section of the barrel at the chamber, but unless I have full-length bedded a barrel, I don't want any contact from the slope ahead of the chamber clear to the front of the stock. If you have contact, or even a questionable tight spot, take a dowel and sandpaper and remove material. When I get done, my stocks look like s-h-i-t but the guns shoot ... or else I sell them and let someone else fight them. Life is short. The other alternative is to buy an aftermarket stock to hunt / shoot with and keep the original in case you ever sell the gun. I'd suggest McMillan. You get what you pay for.
Good luck...
Tom
