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Posted: 11/21/2015 12:58:51 AM EDT
| So I have been looking at ammo and posts around the internet. Can't believe some of the stuff I read. Like this: "Bullet friction does not wear out a barrel. It is the hot combustion gasses that melt away the steel. If friction was the primary cause, the barrel at the muzzle would go first." WHAT?!?!? I found a good article here http://uspsa.org/front-sight-magazine-article.php?Should-I-Buy-BiMetal-Ammo-8 The copper 'jacket' is only microns thick...over STEEL....not the same as a true cupro nickle jacket. If I am in an "End of World" scenario, I wouldn't care about my ammo as long as I had some and it worked...everytime! As for cheap shooting, I am building a 9mm AR carbine...just for that...and to have another AR! I make ammo so I can get tons of 9mm for almost free! I can make 1000 rds of 9mm in about 40 minutes. And here is another great test about steel case versus brass case ammo. I know most steel case ammo is loaded with bi metal (steel jacketed) bullets. If I am wrong, please post a link to the steel ammo with normal copper (cupro nickel) bullets. Here is the test on Lucky Gunner. http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/#cheapest |
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The major contributors to wear and erosion of gun barrels are usually grouped under the headings: thermal factors, chemical factors and mechanical factors. The relative contributions of these factors vary from system to system. Generally, however, thermal and chemical effects are considered to be the dominant factors. But, that is not to say that mechanical factors do not exist....
The mechanism of deterioration includes the embrittlement of the surface layers of the bore by reaction with hydrogen, nitrogen, and carbon at the elevated pressure and temperature during propellant combustion. High pressures cause compression and hoop tension stresses in the gun barrel tube. High differential temperatures cause uneven thermal expansion between the thin surface layer and the depth of the metal. The ultimate result is crack formation, crack propagation, and crack intersection. After a number of rounds, friction between the bore surface and the passing projectile induces shear stresses large enough to remove small fragments of the surface enclosed by pairs of Intersecting surface cracks. The particle may redeposit at the edge of a land along the bore together with copper from the projectile end thus contribute to further erosion. Understanding and Predicting Gun Barrel Erosion |
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