Never hunted the area but have hiked it a bunch. Certainly in September, but even in October and November, I would expect this to be a high traffic area with recreational dayhikers and backcountry enthusiasts. Quandry is one of the easiest 14er's and thus attracts bunches of crowds. Most of the hikers will remain close to the trail along the Eastern ridgeline that leads to the summit, but there are still plenty of others who walk the road into McCullough gulch.
Could still be reasonable hunting, but don't expect to be alone.
One of the things I struggle with when afield is keeping my rifle clean and in good working order. Small amounts of dust and dirt collect moisture; moisture can freeze rendering your action immovable when you need it most. I have seen this happen on multiple occasions, and over time, I’ve learned the cause and how to prevent this from happening.
The first thing that you need to avoid before going afield is leaving excess oil on the gun. Oil will trap dirt and sand in all the wrong places....