Has anyone put a red dot on one of these single shots? Where did you decide was safe to drill / tap? Or did you affix a rail by some other means?

Thanks!

I bought an EGW rail for my .45-70 H&R truck gun. Using the iron sights for now. Will that work on your shotgun? The channel in the middle allows for use of irons without having to remove the rail.  Looking for a red dot to put on it.

There's no rail on these shotguns, it's a smooth pipe until the front sight bead.

The late model ones were just drilled and tapped over the chamber right? I’d ask a couple Smiths if they could tell you if it’s possible. I’d send a pm to Guncat and ask him. If anyone knows It’s him.

There should be four tiny screws over the chamber in two groups of two about 3-4" apart.

If not I can measure any number of SB2s I have for the pattern.

Honestly though I don't expect the sight to survive. The 10ga kicks enough without removing barrel length.

Pretty sure the older guns weren't drilled and tapped

This particular one was manufactured in 87 according to my SN google fu. Wall thickness is 0.200" at breach and muzzle.

What about machining a dovetail (like for pistol sights) somewhere down the bore and making a dovetail - rail adaptor with some rubber under the ends to help with vibration damping?

If you do a dovetail there are already plenty of red dot adapters that mount directly in them no need for a rail

There's absolutely no reason to go with the most recent spec for mounting holes unless you're dead-set on using an NEF/H&R specific mount. I suggest using whatever you prefer - there's plenty of meat over the chamber to have nearly anything there.

As far as the mount with rubber? You'd end up having a shifting zero. I suggest going with a sight that is specifically rated for high recoil. The first I'd probably try on the less spendy side of things is a Vortex Venom RDS. On the higher end is the Leupold DeltaPoint Pro for about twice the cost.

Anything less rugged than those sorts of sights and you're asking for it to break very quickly.