I took my M6 scout to the range yesterday and really gave it a workout. It's quite the gun, however, as could be expected, it's got some limitations.

I fired from a bench rest, at 25, 50 and 100 yards, using a wide range of ammunition.

First, I'll talk about the .410 chambering.
To dispell any myths, yes, you can shoot an M6 with some level of accuracy at 100 yards with a .410 slug. That said, it's unlikely I'd be able to actually kill anything larger than a goat with a shot at 100 yards, given the realtively low muzzle velocity and limited impact power of the .410. Also, the drop of the .410 is pretty severe, I found myself with a "rainbow trajectory" to get on the paper at 100 yards.

On the other hand, at 50 yards, the .410 slug in the M6 was just great. (where I live the .410 is legal for deer hunting!) Not the best groupings, but half of that was me, as I didn't have a bench rest or anything, just a table and a firm grip. But at 50 yards, the .410 slug was consistently where it needed to be.
At 25 yards, the slug seemed a little silly, but I was able to really get a nice consistent grouping and it has quite a wallop at that distance.

For .410 shot, I used #6 shot and did some patterning. Basically, you have a gun good to 40-50 yards, at best, and I found it to have nice tight patterns, consistent and reliable. I also shot a few clays with the #6 shot, getting a sight picture was quick and easy. The amount of shot it fairly small (this is a .410 we're talking about here) so it might not be the best for anything far out or up.

Now for the .22.

Unfortunately, the .22 side of the M6 was basically useless at 100 yards. even though I know that some of the error was me, the overall grouping was not what I'd hope, on the order of 6 to 8" at best - this was with CCI stinger and Mini-Mag loads. At 50 yards, things were better. I had some particularly good results with CCI velocitors, a very fast round that is very flat. The peep sight is easy to use, and fairly accurate, however, if you were to use the M6 in a survival situation, it would be best used in the under 50 yard range, regardless of load selected.

At 50 yards, I was able to get a killing shot in on rabbit sized targets consistently, however, for squirells, it was a bit harder.

Still, the M6 is a cool little gun, and while I prefer something like my ancient lever-action winchester 94 in 30-30, or semi-auto Ruger or Marlin it's not a bad gun for the money. And the guys at the range though it was very cool.

Next test will be with the Beretta CX-4, which I hope to pick up in the next week or two. This is a 9mm Carbine, with very cool styling and some great reports.