Nate, I had a really accurate SKS with the adjustable (ramp) rear sight that I came real close on a few 300 yd prairie dogs in the sitting postion and was able to hit a 16" disk 6 for 6 at 300 yds, offhand at the range.
As far as your comfort range for taking game with it, that is up to you and how well you know the limitations of you and your rifle.
If you zeroed a real flat shootin 300 WSM
@ 300 yds, with a fast lighter wieght bullet like a 130gr TTSX or even a 150 gr E-Tip, you would be getting minimal drop at 400 yds.
Out of a 26" tube I'm guessing you could get the 130 gr TTSX moving about 3600 or better with RL17 and a 150 E-Tip, probably 3400 give or take. With that kind of trajectory if you put the sights on the backbone you would be hitting a deer about mid body or higher.
There are already LR open sights out there...
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