Basically all guns run a risk of breaking in the winter time when temps drop below zero.
Running stock just helps minimize your chances of cracking a mechbox from the piston impact everytime you shoot. Try not to run full auto on your shots and typically your okay to -10 or -15, if your running mini batteries get a few spares as they will drain considerably faster in the cold, and keep your spares under your gear close to your body for warmth.
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