Having become a fan of the 6.5x55 in the eighties, I've scoured sources of information over the years and do remember that specific weight in the 6.5x55, but paid little attention, since my "thing" is for the 160s, so I'm 1) basing this on memory which is stretching back a little and 2) regarding something I wasn't specifically interested in and probably only had an impression of, so what's in MY head regarding these is subject to question/correction.
I remember these being available from before I got interested in the cartridge (6.5x55) and think they were more popular in Europe - being intended as a way to extend the usefulness of a single cartridge chambering. I had the impression they were for common game in Northern Europe - smaller than the typical ungulate. I don't THINK they were specifically varmint bullets, as we see them in the US, but I THINK I remember that weight being available in full-patch ammo, ostensibly to reduce fur damage.
My LEE manual (the first one) shows 70, 77, 80 and 85 grain "jacketed bullets" (no constriction/nose details) for the 6.5x55, using only VV powders, but the Carcano and Arisaka start at 100 grains using other powders, which leads me back to Northern Europe as a possible source of information. Maybe a VV reloading manual has some data, background or application suitability information.
Side-note: I sold my grail rifle (Sporterized 09 Argentine in 6.5x55) to my brother because I just wiull never get to hunt with it and I hate wasting the ever rarer 160 grain Hornady and Sierra bullets on paper. He sent me a pic night before last of a nice 11-point he got with it at 189 yards. He was impressed that he'd zeroed it at 100 yards and didn't think to hold over at almost twice that for the slow, heavy projectile. Tagged it right where he held. I had intended to eventually try 85s in it because wood chucks are plentiful here, but I never got that far with it. 20-year project I never completely finished - the barrel is still "in the white," but dang if this thing won't shoot.
My take - TAKE the bullets and experiment. They're hard enough to find these days and they may turn out to be useful for something, even if it's just for fun. If you're shooting tight twists geared toward long, heavy bullets, you may have to slow them down a bit, but they could still yield a fair amount of trigger-time without using up over-priced boutique bullets of the day or hard to find, older heavies which gave the 6.5 its reputation to begin with. 250 or 500 is enough to find a decent load and have enough left to play with.