I would expect a difference if you had two different throat lengths, and used the same COL for both.
I do recall Ruger 7x57s according to owners, showing a preference towards certain bullet weights, depending on throating that IIRC was changed in production from the older vs. newer mfg. rifles. It's possible they were using factory ammo, not sure.
I have had 'BUGHOLE' accuracy i.e. in two 6mm BRs, both 8" ROT, but one had a very short throat, vs. another with a longer throat made for 105-108s. BOTH shot bughole groups when either light or heavy spectrum bullets were seated into lands.
Yet, most every rifle I had loaded for, showed a distinct preference for being at or into the lands. Often the difference was significant, but always noticeable vs. being short of lands.
