I don't claim to be an expert, but since no one has given a response, I'll offer you my thoughts.
I never measure or load to a COL. As long as they fit in the magazine, they are good. The relationship I worry about the between the ogive and the lands. My Model 16 7mm-08 seems to group best .015 off the lands. Sierra 140 gr Game Kings at .015 off the lands in my rifle have a COL of 2.740. I also have some Hornady Interlock 139gr. BTSPs loaded at .015 off the lands that measure 2.815. These bullets are a little slimmer in profile putting the ogive a bit further back on the bullet making the overall length a little longer.
Two easy things to check regarding the tight clambering. First if you are hitting the lands, your bullet will show the rifling marks. So that's easy to check. Secondly, chamber an empty, resized piece of brass to check if it chambers easily. When I first set up my press to load 7mm-08, I had some rounds that were tight in the chamber. I found the problem was the brass not the COL. Re adjusting my resizing die solved the problem. This of course assumes that the brass was properly trimmed as long brass can also cause clambering problems.
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