The .257 imo is in some ways cooler and in others less cool than the .250
I sometimes consider rechambering my .250AI, to .257AI.
The long savage 10 action my gun is built on, is way oversized for the .250
The .257 would be comfortable in it tho with a 2.9ish coal.
The short .250, with it's realtively short bullets does great in sub 2.8" magazines. Same goes for the 6.5cm, wierd that......
Ive never used the 87s, but again they probably work fine 95% of the time. I've shot quite a bit of game with the 85 sgks out of a .243, and had no issue.
Kills are also noticably more emphatic with the extra velocity behind the 85s, than they are with the 100s that became my standard load. But a 100sp at 2800 will go clean thru on broadside shots, and usually lodges in the shoulder or behind the ribs on quartering.
@CraigC obviously has had issues with the softer bullets, but again as he pointed out, while the options arnt stellar, there are tougher bullets available.
They downside is again in the ooooold guns it's possible to run into twist rate issues.
Which is at it's core the downfall of the .25s.
Slow twist rate limits length, which limits long and/or heavy bullets.
Now again for most usages that's not usually a huge big deal. But the low comparitive BCs look bad on paper, and the long monometals won't stabilize in older guns.
You also won't see alot of bullet development, as there just isn't a whole lot you can do with a design limit of around 1". Maybe a low 80s monometals or bonded, don't think I've seen one of those yet...
Now if there was an industry shift of putting 1-8s on .25s, you might see some interesting additions, but they would all end up looking like the 6mms and 6.5s.
The .25s are hunters cartridges. Yes there are a pile of cartridges, that are "better", but the .25s do what they need to at the ranges most of us can comfortably apply them.
All that said....a Savage 99, or Winchester 88, in 6.5CM would be pretty slick no?