doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com Question about steel used for rear sights

I'm thinking of making a rear leaf sight for my Marlin 30AS, and I would design it something like what's pictured here -- a Marbles flat top or a Winchester 22g. Are sights like this made from plain steel or spring steel? I realize the main part of the sight has to flex in order to accommodate the elevation adjustment. It seems like the spring tension, imparted by that flexing, helps hold the elevator down and in place. But the amount of flex and tension seems moderate. I welcome input on what type of steel would be best. Thanks!

A stepped ramp rear sight needs some downward spring pressure to keep the ramp in place. So I'd pick a medium carbon steel that can be easily heat treated. Something like a piece of annealed steel in the 1050 range would machine easily, and take bluing well.

I would make the sight body from spring steel, I have 1075 so that’s what I would use for the type of steel. That gives you the option to either heat treat or not, without having to make a second one if you use mild steel first. Although, I would make a spring out of it so I could be sure it has a enough down pressure.

The elevator could be made from mild steel or something like 4140 that could be hardened if you want.
Bob

I am not a machinist. Not even on the internet. But if it was me, I would consider making a version of that sight that folds down which may greatly improve carrying characteristics when in the field hunting, and more importantly adds some flexibility when also using the proper tang sight.

Bob, Brent: your input is much appreciated!

Thanks Keith, much appreciated!

Most common off the shelf commercial sights like this not so much a spring, but they flex enough in the soft state that the steel itself does what is needed. That being hold the elevator down against the bbl.
If you pull up on a lot of these, you can bend them easily enough and leave the tang section pointing upwards.
Bending them back is just like bending a soft piece of thin steel and leaves a crinkle in the thin tang where it bent.

Some seem to be made as a spring. Some of the MArbles mfg are very tough and spring like.
But most any steel will have some flex range to it. Wether it's enough to meet the needs of this application is the question.

If I were going about making one from scratch, I would want the thing to be a real spring.
1075 annealed steel works rather easily. The entire sight could be made as a flat piece probably out of 3/16thick stock.

The blade end could then be bent upwards when finished with the above work by heating red.
Then finish any shaping.
Re-polish, harden, then draw the temper to make it a spring.
I use a lead bath at 735F for tempering. Never failed yet.
Imparts a nice temper blue color if you want to leave it as-is.
Smoke the part with soot before the lead bath to avoid the lead sticking to the part. OA torch acetylene gas flame works quick.

You can still cut,file, etc the finished spring if you really need to. Sharp files will do that for you. Polish carefully afterwards.
A thin tapered tang section as a spring will make lifting the sight for elevator adj easy. But still always give secure downward pressure against the bbl.

Thank you, Kutter!

Making one from scratch is a bold undertaking. Having made a few gun parts I can appreciate the amount of effort and time it will require. Is there any particular reason you want to make one as opposed to buying one? While not in current production that sight shouldn't be too hard to find.

Stan,the factory sight on a Marlin 30AS looks like bent sheet metal. It's definitely functional, but it looks cheap. The rest of the gun looks well-built. I tried a Marbles folding rear sight, but I could not get the rear sight low enough to work with the front sight. There are a few rear sights I like the shape of: such as the original Winchester 1894 ladder sights and the Marbles Folding Express sights. I thought I might borrow some features from the ones I like and build my own. Of course, I enjoy the learning process too. With the help of others on this forum I made the blade for the front sight on my Ruger M77 MkII. A talented gunsmith, Matthew Roberts, machined a custom banded ramp, and shaped the blade and placed a brazed brass sighting plane onto it. Kind of a sourdough style blade with a brass sighting plane. I agree building a rear sight from scratch would be a big under taking for me, but I might do it. It's also the kind of project where I can try it, and if it doesn't work no harm done, just reinstall the factory rear sight.

Larry