Great for short-range use, or as an aperture-sight alternative. - Vortex Crossfire II 1x24mm Muzzleloader Riflescope w/ V-Plex Reticle, Black CF2-31047

There are some oddities with my vision that make it difficult to use iron sights on long guns, and red dots don't work either. As a result, I have used these on a couple shorter-range long guns. May not be as quick as a good aperture, but I can actually see the reticle clearly, and having the target in the same focal plane as the aiming device helps a lot on longer shots. Can still easily track the whole scene with both eyes open. The scope is light and compact, so it doesn't look completely ridiculous on traditional long guns. For the price these have been on sale lately, you can't really beat it.