What is the dovetail size of a BSA Standard rear sight?

[45flint]

I have a BSA Light that has its rear sight removed because it interfered with the aperture sight. Would like just to put a filler wedge into the dovetail. Not sure how to measure the size to see if that size is available or if I have to make one.

[trajectory]

Not sure about the consistency of the dovetails, it would be nice to think they were all milled out the same but tool wear & what subsequent owners have got up to over the years plus the possibility of a bit of hand fitting when they were made & ?!? what they are.

I've just measured one, the depth of the slot is 0.092" the width of the narrowest part of the dovetail is 0.409" & the widest part of the dovetail is 0 .435" all are approx, but hopefully fairly close. Guess you might be looking at making one?
ATB

[trajectory]

Measuring......li probably depends on what you've got. Tricky bit is the base width because of the slope on the dovetail. One way is to file a bit of scrap al. or brass, or steel to an acute triangle so the thin pointy bit goes tight in the narrow confined corner, do the same for the other corner so both 90 degree are facing each other with a gap between the faces that are perpendicular to the flat of the dovetail. Measure the gap between the two faces with a caliper & add that dimension the length of the side of the triangle that was on the flat of the dovetail, for both bits.
Not brilliant but it's a ball park figure. Watch out for a taper on the dovetail one side is quite possibly wider than the other.

Cheers