Half the fun of building a gun is putting your own mark on it. I have been experimenting with different methods, and short of buying a CNC rig electro etching is the best method I have found.
I am etching with a jewelry plating power source but a battery charger will work (not an automatic one).
First we make a stencil, by hand or with a vinyl cutter. I use one from U.S. Cutter;http://www.uscutter.com/GreenStar-Intermediate-Calendered-Vinyl-24quot-x-10-Yard-Roll_p_1020.html
Tape is used to pull the stencil from it’s backing in one piece.
The stencil is placed on the receiver with the letters in place.
This makes the stencil easier to place, and gives a solid surface to work against.
The letters or graphics are then “weeded out”. You will need a magnifying glass (I double up reading glasses) a long needle, and tweezers to pull the bits you want removed. Carefully remove (weed) the parts you want etched.
Carefully lift the edge of the bit you want to remove.
Pull the bits away with tweezers.
My charger is set to the full 12 volts @ 10 amps. The amps that trickle through are determined by how much surface area is contacted by the Q-tip. Place the clip about halfway up on the swab. I place a little solution in a shallow container and dip the Q-Tip, make sure it gets wet up to the clip. There will be bubbling, when this slows and the Q-Tip turns black repeat the process. It can be hard to see how deep your going, when the little islands within the a’s & e’s won’t stay in place you’ve gone about as deep as possible.
I should say large open areas do not work as well as smaller outlines.
I use about ½ cup of vinegar and a teaspoon of salt.
Tape the surrounding area to avoid sparks and etching areas you don’t want etched.
I mixed white vinegar with a little salt, dipped a Q-tip into this solution and attached it to the negative side of the charger, then clamped the positive side to the lower.
It takes awhile, and starts slowly, but after you break through the surface the pace picks up.
A few tips in response to some questions I've received.
A cheap NON-automatic automobile battery charger 12 volt, 10 amps should work fine.
An automatic automobile battery charger would read a dead short and turn itself off.
One thing I learned the hard way is that the positive side needs to be connected to the lower and the negative side to the Q-Tip. I got it backward once and it ate away the clip holding the Q-Tip, and barely marked the work piece (in this case just a piece of scrap).
If the bare clip touches bare metal there will be sparks, tape off the surrounding area.
I recommend testing any setup on a piece of scrap before trying it on a lower.
Example of text;
Max is 10 maybe 12 letters/numbers per line.
If you want room for artwork the Manufacture and city should be moved to above the hammer pin/selector area.