After shooting corrosive ammunition some special considerations are necessary. All surplus 7.62x54r ammunition is “corrosive” which simply means that the chemical compound of the primer contains salts which are left behind in the bore and will attract moisture eventually causing rust. The ammunition is not corrosive in the sense that it is acidic and will cause immediate damage to the firearm and with proper cleaning corrosive ammunition will do no more harm than non-corrosive ammunition. Corrosive primers have a much longer shelf life than non-corrosive primers and this is the reason they were used in the Eastern Bloc long after Western militaries switched to non-corrosive primers. The benefit to shooters is cheap surplus ammunition that is still reliable after fifty years or more, with more meticulous cleaning being the trade off. When corrosive ammunition is used the firearm should be cleaned as soon as practical with higher humidity necessitating faster action than lower humidity. It is best to take basic cleaning supplies to the range and clean immediately after the end of the shooting session with a more thorough follow up later. Many shooters have strong opinions on the cleaning solutions and steps to take after using corrosive ammunition. A mixture of water and ammonia or glass cleaner (Windex) with ammonia is popular, but requires a thorough drying and cleaning with solvents followed by application of oil to prevent rust from the water based solutions themselves. Ammonia can discolor stock finishes and should be used with care, preferably removing the stock completely. Boiling water poured down the bore is a method dating back to the days of blackpowder muzzle loaders. While it is effective and the heat transferred to the metal will usually be enough to evaporate any remaining water it requires preparation time and equipment. An accidental spill of boiling water can also be dangerous and there is a chance that water will find its way into the barrel/receiver threads where it can’t be removed. The stock should also be removed to keep it dry and a thorough application of oil is required. At this point many have probably sworn off corrosive ammunition for life, but cleaning after its use doesn’t have to be as complicated as some shooters make it. The old stand by of Hoppe’s #9 was created when corrosive primers were the norm and is formulated to remove the salts which can cause damage. All that is necessary is standard cleaning using Hoppe’s #9, or any other solvent formulated specifically for corrosive ammunition, but paying particular attention to any areas possibly contacted by gases from powder ignition. Other than the bore this would include the bayonet if fixed, the end of the barrel, and even the front sight due to the large fireball produced by some surplus ammunition, especially in carbines. The bolt head and firing pin should also receive particular attention as there is a chance of gas leakage between the primer and its pocket. If surplus ammunition is used regularly the shooter will eventually experience a pierced primer, evident by a puff of gas in the face, which can be due to a soft primer cup or a firing pin with too much protrusion. In this case the bolt should be fully disassembled, except for the extractor, and thoroughly cleaned and lubricated and extra attention should be given to the inside of the receiver and magazine. This applies even if the ammunition is non-corrosive as the hot gases will evaporate any oil leaving no protection or lubrication. Occasionally the idea is proposed that shooting non-corrosive primed ammunition after shooting corrosive primed ammunition will physically remove the salts in the bore. This seems like a waste of expensive ammunition and it is questionable whether it would do any good for areas like the bolt face, firing pin, exterior muzzle, and bayonet. Regardless the firearm should still be cleaned and if a solvent formulated for corrosive primers is used there is no extra work or expense involved.
Before shooting a firearm the bore should be wiped clean with a dry patch or two to remove any excess oil which can lead to higher than normal pressures. It also insures that the bore is not obstructed which can cause catastrophic failure and injury to the shooter. An inspection and function test with dummy cartridges is also not a bad idea, especially if the firearm has been shot and cleaned by someone else or it is a firearm that is not shot and handled on a regular basis.
