Magazine length is a consideration with rifles for larger animals, but since this is posted in varmint rifles... magazine length doesn't matter to me. The rifles can be single loaded. Sometimes loaded cartridges fit the magazine, sometimes they dont. A couple of half-fast rifles have shown remarkable improvement in accuracy by seating long to touch or even into the rifling, so I've begun handloading trials with middle of the road powder charges that show promise with bullets just short of touching, juggling the powder charge for best accuracy then going shorter incrementally with OAL for fine tuning. Sometimes going longer works better, again reducing then working upward with powder charge until you find a safe load you're happy with. The 1st time is a bit of a hump, but it gets easier once methods are developed, procedures are learned, & a maybe few new tools are acquired. You will need a dark colored Sharpie to check for contact when finding the base measurement. A bullet comparator is very useful & fits on your dial caliper. The Stoney Point/Hornady OAL guage is useful but not necessary.
