My dad was a singleshot man, and I grew up using them. My last 13 years or so, I've used an NEF, which I"ve gradually customized over the years with a curly maple stock and steel, rather than plastic ,hardware in 45/70 loaded with either 300 gr JHP's or, lately, 400 gr speer flatnose. Mounts a Leupold 2X-7X scope. Killed a lot of deer with it hunting these thick woods where I"ve never shot over 100 yds. I'm a still hunter, so a singleshot isn't a handicap to me. Before that, I used my Ruger #1 in 6mm Remington, loaded with 100 gr Nosler Partitions, for a total of 18 deer....none over 100 yds away.
My "really lousy weather...can't see schmidt" rifle is an old Krag set up with Williams guide sights, and 180 gr roundnoses.