Measuring max CASE length for your rifle
Recently I was given a box of nearly 100 handloaded rounds for my factory Rem 700-V .243 but upon inspection I found that the cases themselves were a few thousandths over the max length. Now, not wanting to pull all the bullets and trim them all I searched the net about case length. I came across a method where you size a case then cut the neck off about 2/3 down to the shoulder and seat a bullet in whats left of the neck, then use the cut off portion as a sliding collar so that you can test where your case neck bumps the small chamber constriction before the freebore or lands area begin (I don't know any proper terminology for this portion of the chamber). Anyway, I did this test a pile of times and made more than one of these gauges and am confident in the conclusion as it's totally repeatable: that my case necks don't contact the constriction until over 30 thousandths past the max case length! Now, some sources I've read online say this is pretty normal. How many of you guys have done this same testing and found such a big gap?? I would like to keep my cases about 10 thou from the 'constriction' to reduce errosion and get my 75 gr V-Max's out to the lands with more bullet in the neck... it seems straightforward but am I missing something here, playing with fire so to speak? Why is there so little talk about this chamber dimension but so much about the distance to the lands; is it just because it's not so much accuracy related as the lands-to-ogive distance is?
Thanks for any feedback!!