A couple more possibilities,just to kick off some creative thinking.There are a LOT of approaches that are fine.
You could drill a small pilot hole through,and make a shallow countersink or counterbore,not much,on each side.Cut your all thread,or whatever you use,slightly short..Mix your epoxy with the black dye they supply in Accra-glas.
Fill above flush and dress it off.You will have a black dot on each side.
A slightly more "rustic" but acceptable(to me) approach,use something with a head,similar in geometry to a nail.Make or find a small washer that will just slip over the pin.Drill,and once again make shallow counterbores.
Install with epoxy,set the washer over the pin,and peen the end of the pin.
IMO,done well,and cold blued,it could look fine. And its the IMO that counts.
I'm not ruled by my critics.
I have heard of taking a very sharp chisel,and curling up a shaving,leaving it attached,at the site of the pin.After the pin is installed,the shaving is glued back down as a veneer.I lack confidence in pulling it off,myself.
Tangolima
lease do it your way!!With my respect.We are entitled tour preferences.
FWIW,(not an argument) Some would say if the rifle is Walnut and blue steel,the ends of such a pin might look better following suite as blue steel.
But that is pure preference/opinion.Your way is fine.
In my experience,drill rod is usually sold in both hardened and unhardened conditions.It may be W-1 or O-1 tool steel,and sometimes is available in other alloys.
The advantage to drill rod is it comes OD ground to size.
As it comes,I have not used the W-1 much..I have used the O-1 extensively.Frankly,its not my favorite steel.My attempts to eyeball torch harden and draw parts HAS disappointed me with brittleness on more than one occasion..
With pro heat treating,its a lot better,which says my heat treating is poor.
And,like any oil hardening,it warps in quench
But,as purchased,soft or hard,I think it would hold up to the task of being a pin.
Now,if you need to make a gun part out of something "good"look up "Mold Core Pin" DME might be a supplier.
They are heat treated,od ground,and made of H-13.They come in two hardnesses.CS,and CX.I forget the Rockwells,but the CS will cut with high speed,and the CX willcut with carbide.
For really hard/tough,mold ejector pins are not only ground and polished,they are nitrided toover Rockwell 50C,maybe near 60.
Core pins and ejector pins come with heads,that are usually annealed.
A couple decades of moldmaking ....