Do you think this would make a good black bear rifle
Personally, I think the handiness of that rifle would be a plus for a stand hunter and it definitely has more than enough power. That Ruger Compact in 300 WSM isn't my cup of tea but it would get the job done.
So before I offer my opinion of a stand blackie rifle, lets just say that the rifle in question would get the job done.
I take a group of 12 to Alberta for Black Bears every year. We have several guys that go every year but, every year, we have a couple of new guys in the group.
For the most part, shots are between 10-30 yards with an extreme of 125 yards.
The gun I recommend the most is a Marlin Guide Gun in 45-70 w/ a middle of the road load. With kids, they will usually shoot the Remington "safe for all guns" load.
Normally, I just tell them to shoot it as it is out of the box or put a nicer set of sights on the rifle.
So guys have to scope, I recommend a scope with a low power setting of 1x or 1.5x.
How much will the 16 1/2 inch barrel hurt the performance
I have to figure that you are stand hunting, how long of a shot do you plan on taking?
Honestly, the bullet is probably in a better performance impact speed, due to velocity loss because of the extremely short barrell, for the close range shots.
I have never seen a Black Bear drop at the shot and stay put unless it was hit in the head or neck.
In less than 7 days, I had 3 canadian black bears (300-500lbs) in a row each drop to a single shot , out to ~75 yards, to a Marlin Guide Gun in 45-70 shooting 400gr Speer using full house loads. All shots were roughly broadside or slightly quartering away and into the chest cavity. None of the bullets exited. All of the bullets fragmented completely. Truama to the vitals of every bear was massive.
Despite the killing performance, each bullet "failed" as far as I am concerned and I have never loaded them again.