A Win 95 in 405 Win wouldn’t be a bad rifle to use for brown bear but two issues come to mind. Open sights and bullet selection. So range would be limiting and finding a really good tough bullet may be challenging. The climbin-Lyman peep might help some but still, for certain bullet placement, the range will be limited. Those big bears can be tenacious. I can’t remember the bore-groove diameter on the original I had but it wasn’t “standard”. I didn’t pursue “dedicated” DG bullets for mine. Hawk bullets with thick jacket may be option.
One spring out on the AK Peninsula I was in back seat of a super cub with JS Swiss flying. We had been watching, through a scope from camp, a large boar hanging around a freshly opened den. I was trying to get some pics so JS made a couple of passes over the bear tipping over at a steep bank each time. On the second low pass (statute of limitations expiration low
that boar lunged up and took a swipe at the plane! Ornery boar! Later JS said that bear was hanging around that den probably trying to dig out a sow with cubs that were still inside.