shoplert - Hello.
The AR-15 is a model number originally from the Armalite corporation.
The M-4 is a military designation for a specific, military purchased version of the AR pattern rifle, largely purchased from either Colt or later.
In my opinion AR-15 will be the best for hunting, very good customization.

lisser - I agree with shoplert. You can find more detailed information in google. When it comes to hunting, the choice of rifle depends on what kind of animals you are hunting. Personally I prefer to use Remington Model 700 with digital scope from https://www.agmglobalvision.com/night-vision site. These devices provide a lot of new possibilities for hunters!