After firing factory, I was wondering the same about tight chamber. My 700 eats everything no issues. Shot the same ammo no heavy bolt lift in the 700. My velocity through the chrono is pretty consistent, didn't see any spikes or drops. Thanks.
I have been getting average velocity of 2724 with 150 grain Nosler bt's and average 2450 with 165 btsp. Only issue I have had is hard bolt lift with almost all ammo. Not every round but a consent. Contacted Sig, haven't heard back yet.