I recently began a restoration of a 1912 Rem. model 12a 22LR. The overall condition was good, but the bore was badly rusted. After an overnight soak with traditional rust removal products and many strokes with a bronze brush, the rust remained.

So I set up an electrolysis tank using a battery charger for power and after a 5 hour soak got all the rust out. Original bluing was untouched, bare steel was bright, and inside the barrel was chrome bright when looking with my Teslong borescope camera.

Have you guys ever tried this method? What were your results and concerns?

I've read that hardened steel will tend to suffer hydrogen embrittlement using this method, and that the fizzing that occurs during the soak is hydrogen gas being released. Not sure how much of that concern is overstated theory and how much practical?

Any and all opinions and concerns appreciated.

BTW: my Krag is in fine shape so not contemplating taking it for a dip just yet. 

Yes, easy to make a mistake. But in today's world of instant information, it was easy.

Bought some Arm & Hammer Laundry Booster and Wash Soda (Sodium Carbonate) at wally world. That and a 2 amp battery charger and a length of cold rolled steel and some copper wire is all that's needed.

Don't use Bicarbonate of soda. Not the same thing.

As I wrote, no effect on factory bluing, or parent metal. Just the rust is removed.

I did not try it on any hardened steel.

My recent reading on electrolysis suggests that the bubbles given off by the anode is oxygen with hydrogen being given off by the cathode. If this is correct, hydrogen embrittlement may be less of a concern.