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Old 07-13-2010, 07:24 AM
AJinNZ AJinNZ is offline
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Default Gun metal composition

I have been wondering on this for a while. I know that older guns designed for black powder cant handle the higher pressures of nitro loads.

I assume they were basically made from mild steel. What is the composition of modern guns/rifles?

Does it change for different uses/calibres?......a .357 pistol with hot loads vs a 458 win mag rifle vs .22 rimfire?
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Old 07-15-2010, 04:25 AM
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4130/40 is a pretty common alloy for modern firearm receivers and barrels. Every receiver I have made is from those alloys.
Some manufacturers are selling barrels of 41V50 claiming its "mil-spec"

No I dont think you will see much variation due to caliber. I have 4140 5.56 and .50BMG barrels

The receiver itself can be made of anything. Typically only the chamber and the barrel matter. There are guys out there making AR15 lowers out of plastic cutting boards and Sten's from cardboard tubes. Its very common on rewelded receivers to repair cuts through the chamber. Some of the repairs I have seen are pretty scary, No welding experience and a 110v HF fluxcore welder, and they hold together.
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Last edited by Cavalry; 07-15-2010 at 04:34 AM.
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Old 07-15-2010, 07:38 AM
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Thanks Cavalry, very informative. Just what I wanted to know.
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Old 07-15-2010, 07:52 AM
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WW II M-1 Garand receivers were made from 3115, 3120 or a modified 8620 at various times. Case-hardened 8620 is still commonly used in rifles.
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Old 07-15-2010, 11:24 AM
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A little reading on Garand steel
http://www.eotacforum.com/viewtopic.php?f=109&t=51729

On my 1937 Garand Print the material bill is Fed-Spec QQ-S-624, FS8620.

I have a modern Garand "casting"..material is 4140
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Last edited by Cavalry; 07-15-2010 at 11:34 AM.
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Old 07-15-2010, 04:07 PM
AJinNZ AJinNZ is offline
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I assume that the bolt head and lugs would need to be the same composition as the chamber and barrel in order to resist the pressure back?

Last edited by Shade Tree Welder; 07-15-2010 at 05:44 PM.
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Old 07-15-2010, 05:44 PM
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Quote:
Originally Posted by AJinNZ View Post
I assume that the bolt head and lugs would need to be the same composition as the chamber and barrel in order to resist the pressure back?
Yes..
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Old 07-16-2010, 04:10 PM
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Gotit

So are revolvers any different?

The thread on the blown up revolver cylinder was what got me started on this. They seem inherently weaker in design than a rifle chamber.....
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