IME, clearance is clearance when it comes to bolt lift issues. They are more commonly due to the case being too fat rather than too long. Just look at a couple of examples that intentionally are designed to have snug bolt closure on unfired brass, like any Ackley Improved or even a PPC. They go in snug but the bolt opens easily if everything else is right. Bump the shoulders back on old brass from another barrel and hard bolt lift is common, even if it was bumped back a few thou. If it's tight in the web, you'll get hard bolt lift, or click.
If bolt lift is hard from the start, it's either too long or way too hot. If the bolt rotates pretty freely until near the top of the stroke, then kinda snaps open and it clicks at the top of the stroke..that's not length, ime, but case diameter. That one is harder to fix long term but it too can be managed, to a degree.
That said, I bump more than a lot of BR shooters. I like at least .002", where some try for like a half thou. That can work but as the brass ages it becomes harder to maintain such consistency between pieces of brass, even from the same lot. The way I see it is, I'd rather have it all a tad loose opposed to having some tight and some loose. We might still be talking the same half thou difference but with all having some clearance rather than some that the stripped bolt drops on and some a bit snug. I think we sometimes outsmart ourselves, looking for an edge where it matters little, if at all. We must keep things in perspective here. If we move the shoulder .002", that's about half of what a human hair measures. I think that there are more important areas to spend our efforts improving upon, is all. Kinda like tight threads...Too tight can only cause problems and it gains ya nothing.
Just my 2 cents worth.
