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Discussion Starter #1
So is this xm80cs ball on the market going to harm a chrome lined barrel? I would think no? Correct?
 

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Your going to get two answers, 1) yes, 2) no

Just like the many threads asking the same question before you.


You'll need to decide the answer that fits you.

I agree with you as my engineering exprrience tells me the same. Lets look at it this way. SAAMI specifications for a .308 barrel is a bore diameter of .300 and a groove diameter of .308 meaning the rifling is .004 in height (.300 plus .004 X 2 equals .308cal). Now projectiles for this cal are usually around .3090 minus up to .0030 and they do vary quite a bit based on the thousands of rounds that I have loaded over the years.

Now take into condideration that all projectiles are going to deform to the barrel unless the projectile is made of harder steel than the barrel. This deformation is what causes the projectile to engage the rifling making the projectile spin or rotate if you prefer. If the projectile is harder than the barrel, the gun will explode because the .308 projectile will not deform to the .300 cal barrel. You also have to remember that the barrel DOES NOT remain static during the firing process. Heat and pressure will allow the bore to grow in diameter. This is why a cold barrel will be more accurate than a hot barrel.

So the issue is the deformation of the projectile. I submit that whether the projectile is copper washed, copper clad bimetal or copper jacketed, due to the deformation there will always be copper engaging the rifling as the projectile initially starts its travel down the barrel. Here is the potential issue. Will the copper clad, copper washed, or copper jacketed projectile survive the entire travel down the barrel with sufficient copper intact gliding along the grooves and bore (rifling) before the friction obliterates the copper around the projectile.

What I can say is that so far, every copper jacketed and copper clad bimetal projectile that I have recovered intact, the copper jacket has survived intact. Allbeit, I do not make a habbit of recovering many fired projectiles though.

There are a multitude of variables that have to be examined and emperical evidence indicates that there is minimal additional wear caused to the barrel when a bimetal projectile is sent down the barrel ONLY if the jacket does not remain intact.

I think an argument can be made on both sides but unless a thourough examination is made we will have to decide for ourselves whether it is bad to shoot a specific ammo or not.

As I indicated, I do not do FA fire nor do I do rapid fire so the bimetal rounds that I choose to use do not affect the barrel in any significant way to cause me any concern as the barrels of my firearms will outlast me in the longevity arena.

Your firearm, your choice. JMHO.
 

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I was told if its non magnetic your good to go.
 

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You've opened a can of worms with this question. Every round that you fire through the barrel "harms" it on a microscopic level, all barrels will eventually wear out no matter what kind of bullet is fired through them. Will shooting bi-metal bullets destroy a chrome lined barrel in a few hundred rounds? Nope! Will your barrel last a little longer if you use only copper jacketed rather than bi-metal bullets? Most likely, but many factors such as rate of fire, powder type, etc. also affect the longevity of a barrel.
 

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Discussion Starter #6
Thx, not trying to cause issues. I have a bunch of Port that has a metallic jacket. I don't rapid fire so I am going to use it.
 

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The true questions are: will the use of the ammunition affect the useful life of the barrel; will the cost of the ammunition justify the accelerated wear of the barrel; will the cost savings justify the replacement cost of the barrel; what is more important accuracy over useful life or cost savings; what is the intended use of the barrel self defense, competition, plinking, military/police/security and/or multi usage; how do you define useful life (what criteria will be used per the intended use); what ammunition will be used (manufacturer, ammo type, ammo specification, ammo class, etc); what ammunition was the barrel designed for (intended use/application); what type of barrel was the ammunition designed for (intended use/application)?


The bottom line is the answer is both easy and difficult.

The quality of the bi-metal ammunition can be influenced by manufacturing method, bullet design, quality of components used by the manufacturer, state of the production machinery, quality control of final product, etc. There is copper washing, plating and clad bi-metal bullets and each can affect barrel wear differently.


If your weapon is a SCAR then using bi-metal ammunition may not be the best choice due to the high cost of the barrel but a run of the mill AR10/LR308 barrel would be a better choice but this is dependent on what the user values most, accuracy, ammunition cost, not replacing the barrel, firearm usage (how many rounds to be fired), etc.

Bi-metal ammunition has been shown to accelerate wear and the mild steel can contact the rifling in a barrel; there is also nickel plated bullets (rare) that will also accelerate wear. Many indoor ranges will not allow the use of bi-metal ammunition due to damage to the range and outdoor ranges will not allow them due to fire risk. At my gun club this type of ammunition is banned and they will check all foreign ammunition for steel and will not allow the use of ammunition that attracts a magnet (exceptions ammo shortage and Hornady).

The ammunition I purchase is designed (not caliber) for the firearm I am using for the purpose (bullet design/weight) I am shooting taking into account maintenance and useful life of the firearm with the ammunition cost as secondary. The short answer I pick quality ammunition from quality companies.

The ammunition industry is very complicated (proprietary technology and government contracts) as the product is dangerous and this is one of the reasons people have so many questions. It is possible to purchase ammunition from a quality company that was rejected due to not meeting the specifications of a client and the ammunition can be repackaged and sold to consumers.
 

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All U.S. M80 ball is magnetic. all US and Greek M2 (.30-06 ball) is magnetic. At least all I've ever tried.

My opinion? Shoot it (if your club allows it).
By magnetic you mean, if you hold a powerful magnet near a bullet you'll get a reaction, cause my lake city M80 didn't move at all, and it was a serious magnet
 
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No firearm is impervious to wear, and sure different materials will wear at different rates. But we are still talking about the SCAR, right? This is a combat rifle we are talking about, a machine gun without the fun switch, essentially. Anyone who gets so wrapped around the axle about barrel wear as some do in threads like this should have bought an Accuracy International, not a fighting rifle. I recall doing all manner of horrific things to my M16A4, and it still shot well enough to hit man sized targets at 500m, with irons. God only knows how many rounds were through it before i got my hands on it. As long as we are talking about the SCAR and not some 1000m match rifle, my advice, based on my experience, is don't worry about it.
 

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By magnetic you mean, if you hold a powerful magnet near a bullet you'll get a reaction, cause my lake city M80 didn't move at all, and it was a serious magnet
Interesting. Try touching the bullet to the magnet and see if it sticks. My Lake City M80 definitely does stick to a magnet. One of those telescoping pen-type magnets.

Prvi .308 doesn't, Lithuanian GGG doesn't. But all of my U.S. M80 does.


FWIW:

http://www.luckygunner.com/7-62x51mm-149-gr-fmj-xm80cs-federal-500-rounds-loose

Note: This product contains steel in the projectile (this bullet is magnetic) as it is made to military XM80C specifications.
 
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