By no means am I minimizing the logistical difficulties involved in making a change., or for that matter, the "overall" excellent service the series/system has given.
However, I have personally received information that the direct-impingement system has caused, and is now causing, some serious problems when a weapon is most needed, and in enough cases that it warrants serious attention.
In those cases where people are choosing their own unit weapons, they are rather uniformly choosing weapons with piston-driven systems.
PS, I know nothing about operations in arctic conditions, but thanks to you, I'll try and get up to speed in that area as it relates to this. Thanks for the heads-up and