For me,

Lack of neck tension can be either too soft or too hard, BUT i've never had "not enough neck tension" from too soft of brass. I HAVE had it from too hard, but generally the necks crack when the brass gets that (hard) brittle.

"If" i could only get 5 loads out of my brass and i don't give a damn what cal. it is!!! I would blame either junk brass or loading to "too high of pressures"!!! I've NOT had any "brand name brass" that was junk to this date though!!! YES, i may loose one or two "once in a while", but NEVER more than the occasional one.

The way i've always annealed brass was to clean and deprime it, then stand it in a pan of water up to near the shoulder. I then use a propane torch around the neck untill it changed to the desired color. Once that was done, i'd knock it over into the pan of water and go to the next one. Nothing fancy about it, but it always worked!!

Maybe something "else" will work better for you?????

Drilling Man