Thing about sporterized military rifles... some were thought out and executed better than others. If somebody just has to lighten a .303, IMO, the one pictured here appears to be much better than a good many I've observed... almost a jungle gun. I'd rather have it than the 6.5 I really don't know much about, but I've noticed there's a lot to learn from oddballs, too.
The Mosin-Nagants... I never saw one I'd worry too much about. Had I wanted a shorter one for a deer rifle, I'd have chosen a carbine version and kept it as original. Just no perceived reason to alter one. The concerns would've been trajectory with hunting ammo relative to the sights as it applies to where I hunt.