The Firing Line Forums - View Single Post - Proper Lubrication for M-4

Bart Noir · June 12, 2013, 07:09 PM

Those old machine guns needed the oiled cartridges because they had more violent (swift and strong) extraction due to the type of lockwork. Some were only retarded blowback

With other machine guns, such as Maxim, Browning gas (Colt - Marlin), Browning recoil (M1917) and many more, the extraction was slower and the brass case had time to contract. So no oiling needed.

And that is why some did it. H&K solved the problem by using the fluted chamber concept but I think they were not first. I just can't remember who was first to use that.

Steel just doesn't contract back as much after firing so with some ARs, which might be on the smaller side of allowed chamber variations, the steel can possibly stick. Or, as mentioned, some chambers may be finished a little rougher.

OBTW, not a good idea to fire US steel cased .45 ACP (from WW2 - they made billions of those) in revolvers such as the S&W or Colt M1917 models. Extraction often goes at the speed of three hands using dowel rods and a small mallet. Learning occurred that day.

Bart Noir

June 12, 2013, 07:09 PM	#29
Bart Noir Senior Member Join Date: August 5, 2000 Location: Puget Sound, USA Posts: 2,215	Those old machine guns needed the oiled cartridges because they had more violent (swift and strong) extraction due to the type of lockwork. Some were only retarded blowback With other machine guns, such as Maxim, Browning gas (Colt - Marlin), Browning recoil (M1917) and many more, the extraction was slower and the brass case had time to contract. So no oiling needed. And that is why some did it. H&K solved the problem by using the fluted chamber concept but I think they were not first. I just can't remember who was first to use that. Steel just doesn't contract back as much after firing so with some ARs, which might be on the smaller side of allowed chamber variations, the steel can possibly stick. Or, as mentioned, some chambers may be finished a little rougher. OBTW, not a good idea to fire US steel cased .45 ACP (from WW2 - they made billions of those) in revolvers such as the S&W or Colt M1917 models. Extraction often goes at the speed of three hands using dowel rods and a small mallet. Learning occurred that day. Bart Noir __________________ Be of good cheer and mindful of your gun muzzle!