First, Thank you Gentlemen. I had no idea that this volume of quality info could be had on any public board in just a single day. I quit them about 10 years ago being just turned off by how people always just degenerated into conversations similar to what's developing here. Hey- we are what we are though.
I'll accept that I'm thinking too much. I'm not at the technical point in my prowess to be worried about those effects translating onto the "target". I have yet to get any trigger work done.
Myself I understand Fred's sentiment. I shoot for fun. I learn for fun(and brain exercise). Let me extend Fred's point a bit with an analogy using my favorite group of backward enthusiasts- bicyclists. They will pay a few thousand dollars so that their exercise can be easier... carbon fibre bike, shave all the hair, teflon stretchypants.. etc. Me I would strap on a huffy and a large windbreaker and get 3x the amount of exercise per mile than them... because it's HARDER.
So I buy a $5000 marksman rifle and I can hit a target at 800 yards under MOA... but my BUDDY, he can get under MOA at 600 yards with his NAGANT! One of us is truly doing something special.
Funny really, I don't disagree with the counter opinions regarding war weapons.. but one of my 54R's is tight to 308, a late 70's 27" finnish army marksman/sniper trainer, based on the Nagant. fully ALL of my long range target shootin' is strictly with war weapons including Lee ENfield (can't beat that report), 1903A3, M14. Can't beat the prices either. I still get to "tune" them with diminishing returns but improvement is success and it feels just as good.
The M28/76 is floated by the army already.. and that trigger- wow. How cool is the peepsight?? original euro tracks for sling and bipod! There may have been one of 2 of these aimed at terrorists durign the olympic games fiasco back in the day. (See Mr Willard, I CAN combine firearms and history.. you were wrong, and you're still a high school history teacher.)
Some take-aways then...
1. "in-flight" Sectional Density is technically better when a given bullet is fired through a statistically tight bore verses a loose one of the same base caliber... but "not by enough that it matters".
2. a .308 diam bullet fired through a tight-bore .311 rifle does *not* have "better ballistics" than a .311 diam bullet fired through same. They are equal even though they started out at different diameters..
3. SD is calculated using unfired diameter and weight... and I say that method is just a bit flawed technically.
Ok Guys.. thank you sincerely for the input. I plan on learning more about the concepts you have presented by revisiting the text a dozen times as I progress.