ORIGINAL: Hard Luck
My favorite all time semi for deer is a Winchester 100 .308But it takes some tinkering to get it to work right. The very best deer rifle I own is a Browing bar carbine with wood stock in 06 shoots better than any gun has a right too ! But, it is a little bulky and heavy. I've never cleaned it in 20 yrs and it just keeps on working with 3 shot groups running 3/8 inch at 100 with about anything you put in it. I've killed about a 150 deer with it.
The Win. Mod 100 needs to be taken apart and cleaned reg. I had one, and it is a little tricky to take apart, if you don't it will jam up. Myself I don't care for semi-autos for Deer hunting, Most seem to just start pulling the trigger, knowing you have a second and third shot at the next pull. A bolt or single shot will make you a better shot. JMO