How does an M1903A3 rear sight mount?

[s2brutus]

I don't have an '03A3 at hand to look at, but here was my idea:

I've got a Guardia Civil 1916 Mauser in .308 that had the standard sight mounted just ahead of the receiver. A friend of mine wrecked it taking it off, and I prefer a receiver-mounted peep anyway, so I wanted to put one on this rifle. I've seen where you can get a decent quality reproduction 03A3 sight for about $25-30, so I was thinking that might be a good candidate - Just mill a flat spot on the rear receiver ring and drill and tap a couple of holes to mount it.

The question: Does the 03A3 sight have two screws side by side, or front and back, or one screw and a keyed/dovetailed slot for alignment or what?

I figure if it's just a flat base with two screws this ought to be a real simple fix.

 

[cracked butt]

I haven't looked at mine in awhile, but I'm pretty sure that is sort of a reverse dovetail arrangement with the male end of the dovetail being on the receiver bridge and the female dovetail on the sight.

Just mill a flat spot on the rear receiver ring and drill and tap a couple of holes to mount it.

If you make a dovetail piece to fit the sight, you could probably screw that to the receiver bridge and then mount the sight.

 

[nbkky71]

The rear sight base on the 1903A3 was held in place on the dovetail by either a set screw or peening the base.

To install a new 1903A3 rear sight, you first need to disassemble the rear sight by removing the yoke, windage screw and windage knob until you are left with the stripped rear sight base. Drive the base into the dovetail & align the mark on the rear sight base with the witness mark on the receiver bridge. Either peen or screw the base into place & the reassemble the rear sight.

I've heard of some shooters that will set the rear sight to mechanical zero and then attach the entire rear sight. They'll then drift the entire rear sight in its dovetail until their rifle is zero'd. Once zero'd, they'll then disassemble the rear sight components (leaving the base on the rifle), stake the base into place and then reassemble.