Home Forums Hunting & Shooting Rimfires New Rimfire From Winchester

I'm going to guess that it's a 5mm again.
They've got the bullets designed for the .204 Ruger to work with now, as opposed to when the 5mm RM came out. It will probably have a 32gr Nosler BT or a Hornady Vmax, as the first load.
The reason: lots of places here in the east ban centerfires, but allow rimfires, and people want better performance at distance with what they can legally use
.
In short, the same reason the .17HMR sold so well: cheap compared to .22 centerfires for non-reloaders, usable almost everywhere, superior to the .22lr, flat trajectory.