I used to use a saddle mount (which I think all the B-Squares are) on a Remington 870 and one needed to remove the mount to see the front bead. I have used the regular (cheap, under $50) Tascos, Simmons, Bushnells, etc. but find the internals go to hell rather quickly from the heavy recoil of slugs. I currently have a Simmons shotgun scope on a Beretta 390 which has survived about 500 slugs so far. The others seemed to let go any place from 100-300 slugs. This may not be a fair comparison as the 390 is a gas operated semi-auto to which I have added recoil reducers front and back but it does shoot nice. Expect to pay at least $100 for a scope that can withstand numerous firings of slugs, closer to $200 may be more like it. If you are diligent in searching, you may be able to pick up a good deal, my current Simmons was $30 at a closeout, normal price was $89 three years ago. I have not used a RedDot on mine but the more expensive ones used on competition handguns may survive; the cheap ones, maybe not. I think any firearm that shoots a single projectile should have an appropriate optical sight on it as one is much more accurate so equipped. The only guns I own without a scope or Reddot type sight is one of my carry pistols and my muzzleloader.