RE: Hunting with a "milspec" shotgun.
propmahn said it right... don't go hunting with ANY gun without knowing where it hits... you might as well close your eyes and pull the trigger and hope you hit something.....shooting slugs from a smoothbore shotgun with minimal sights is iffy... you might get lucky and have it hit pretty much point of aim at 50-70yds... but you might just as well be 6" low and 8" to the left at 50yds.... use the ammo you intend to hunt with, and go put at least 20 rounds through it, to make sure the first 4 or 5 weren't just a fluke.
now... back to the gun itself... sounds like a good one. If it has some sort of ghost-ring sight, or rifle sights, you are miles ahead. Just because it isn't a "hunting" shotgun, doesn't mean it won't do the job, and do it well. I used my Mossberg 8-shot defense shotgun to hunt pheasant with... raised a few eyebrows... and I'm sure I got a few sympathetic glances... until I started knocking down pheasants with it. I ended up with as many as anybody else on the trip. The only thing I gave up was the longer shots... no choke. But it did the job... and did it very well. Run what you brung!!
"Progress, far from consisting in change, depends on retentiveness..those who cannot remember the past are condemned to repeat it." Santayana