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2021-08-30 Science & Technology

Brass vs. Steel Cased Ammo – An Epic Torture Test

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Posted by Besoeker 2021-08-30 00:00|| || Front Page|| [6 views ] Top

#1 To me the important question about M-16 is "Why the F&CK the manufactures couldn't invest additional 10$ per and make it from stainless steel?!?".

Posted by g(r)omgoru 2021-08-30 00:51|| 2021-08-30 00:51|| Front Page Top

#2 I have seen chrome plated automatic weapons glistening in the sunlight in the hands of Brazilian military sentries along the walls of a fort on the Amazon.

Posted by Ebbomoger Speaking for Boskone4589 2021-08-30 01:22|| 2021-08-30 01:22|| Front Page Top

#3 ^There is, a little, difference between chrome plated and stainless - ask any soldier.

Posted by g(r)omgoru 2021-08-30 01:32|| 2021-08-30 01:32|| Front Page Top

#4 210830 @ 00:30

It is the internal ballistics and the metallurgical properties of the two metals of the barrel and of the bullet.
Two metals sliding against each other produces heat.
Enough heat and the two metal surfaces can begin to melt and fuse, which is called galling.
This is common with stainless steel bolts, in engines and bearings that get hot.
Many high performance gun barrels and chamber parts are either made of stainless steel (approx 10% chromium) for high temperature performance or are chrome [chromium] plated to prevent rust and wear.
My father chrome plated his Cessna Continental engine cylinders.
A few months later he found chrome flakes in the motor oil.
When he removed the cylinder he found the rings had destroyed the chrome plating on the cylinders.
I think my father used chrome plated rings in a chrome plated cylinder which is contraindicated.
I think stainless steel on stainless steel has poor friction qualities especially under high temperature performance.
Of course steel can also gall so steel ammo has to be coated.
Chromium is very expensive, more than copper or brass, and then it would have to be coated to reduce friction which obviates the extra cost over just plain steel.
Brass has much better frictional properties than stainless steel and can easily be impregnated with high temperature lubricants like molybdenum disulfide.
An interesting article on gun barrel material:
best gun barrel material

Posted by boomerc 2021-08-30 04:29|| 2021-08-30 04:29|| Front Page Top

#5

As a long time reloader.
I go with a balance of cost, PSI delivered at x Ft. and accuracy at 100 yds.

Regarding Steel Bullet heads vs. Brass/lead heads
I'll pick Brass/lead. They mushroom better and don't quickly wear down the barrel rifling as steel would.

BTW: While I have owned a small collection of firearms in various calibers since I was 12 (50+ years ago). For the life of me, I cannot say I have ever wasted 10,000 rds pinking using any particular firearm I have owned. Including a 10/22 Ruger squirrel/rabbit gun, I purchased @ Jim's Pawn Ft. Bragg 1990 to train my kids.

Posted by NN2N1 2021-08-30 06:56|| 2021-08-30 06:56|| Front Page Top

#6 I have seen chrome plated automatic weapons

I'm not doubting it for a second. I think the mention of chrome was referring to chrome lined chambers in the rifles, not the external finish. You can still order chrome lining on barrel chambers from several barrel and upper makers, but melonite is much more common now. If the chamber is hard enough, it's the cartridge case that will lose in the frictive struggle. All the same, put enough rounds through it, it will wear out. Entropy is the big picture term for it.

Posted by M. Murcek 2021-08-30 09:11|| 2021-08-30 09:11|| Front Page Top

#7 Excellent discussion and points made.

Posted by Besoeker 2021-08-30 09:14|| 2021-08-30 09:14|| Front Page Top

#8 Once I adjusted the angle of feed on the AK-74, the bolt over stoppages stopped.

I have stuck casing issues from time to time, owing to how the head space was set. Mine was set barely in one end of the tolerance. I get stuck casing stoppages every 700 rounds or so. Can't be helped. My guess is that the Russians ship their commercial rounds with the tolerance a bit looser than their army issued cartridges.

I use Silver Bear 60 grain cartridges. I've shot close to 4k rounds through the AK using only those cartridges. The rifling still is pristine. The barrel is made in the USA, as required by federal law.

My guess is that the actual armory issued Russian made AK-74s with the original 7N6 (5.45x39mm 53 grain) cartridges prolly function flawlessly from round 1 to 10k.

Just my two kopeks.

Posted by badanov 2021-08-30 09:36|| 2021-08-30 09:36|| Front Page Top

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