Cleaning Corrosive Ammunition Residue - Part II
by Kirk Lawson

In a previous article I discussed what corrosive shooting residue is, why you want to clean it, and some methods for doing so. In this article, I present a cleaning method and cleaning fluid recipe from 1921, just post World War I. Quoted below is an excerpt from an official U.S. War Department document, teaching the Doughboys how to clean the bores of their rifles:

Rifle Marksmanship
U.S. Government Printing Office, 1921
War Department
Document No. 1021
Office of the Adjunct General

54. Cleaning the bore after firing.

When the rifle has been fired the bore must be thoroughly cleaned not later than the evening of the day on which it was fired, and then must again be cleaned each day for three days thereafter. The barrack cleaning rod and cut flannel patches will be used as described in the preceding paragraph. First swab the bore thoroughly with two successive patches wet with the sal-soda swabbing solution. The preparation of this solution is explained in paragraph 162.

The bore will then immediately be swabbed with a number of clean, dry patches until a patch run through the bore five or six times comes out fairly clean. The bore will then be examined by holding the breech up to the sky and looking through the bore from the muzzle. Examine the surface of the bore, particularly near the muzzle. If small flakes of bright metal are seen adhering to the surface of the bore, usually on the lands, this is metal fouling from the cupro-nickel jackets of the bullets, and the rifle should at once be taken to the supply sergeant or mechanic to have this removed with the standard metal fouling solution. If the bore appears spotlessly clean the soldier will then swab it thoroughly with a final patch saturated with heavy grease (cosmic), and will put it away in this condition until the next day, when it will be cleaned again in the same manner, first removing the grease with patches before applying the swabbing solution.

The combined residue of powder and primer is very acid. The sal-soda swabbing solution neutralizes the acidity of all the fouling it can reach. Some of the fouling, however, is covered up by the slight metal plating that the barrel receives from the bullets, and this covered up fouling sweats out onto the surface of the bore for two or three days following the first cleaning. If it is not neutralized by again cleaning for three days after firing, it will attack the steel and cause rust.


162. Preparation of solutions.

a. Sal-soda swabbing solution.-This should be a saturated solution of sal soda (carbonate of soda*). A strength of at least 20 per cent is necessary. The spoon referred to in the following directions is the model 1910 spoon issued in the mess outfit. Sal soda, one fourth pound, or four (4) heaping spoonfuls. Water, 1 pint, or cup, model of 1910, to the upper rivets. The sal soda will dissolve more readily in hot water. The solution is also more effective if used hot.

*Editors Note: Carbonate of soda can be purchased. It can also be made in small quantities from standard bicarbonate of soda, also known as "baking soda," commonly available in the baking aisle at the store. Spread the baking soda evenly on a baking sheet and heat in the oven at 200 degrees for one hour.​