Barrel wear?

[leadbutt]

The last time I asked no one could really answer or did any studies on if pc adds more wear to the barrel then just lubed cast boolits. Has any new info come to light? Thanks.

L. Bottoms

[M-Tecs]

In high velocity cartridges barrel wear is from erosion from hot gases and barrel life can be relatively short. On low pressure rounds like the 45 ACP with standard cast 100,000 rounds don't show appreciable wear. Never shot a PC bullet but head to head testing will take awhile.

[odfairfaxsub]

Lol, by the time you shoot 20 k from your pistol your going to be obligated to buy a new barrel anyway prob bc your lugs are rounded or bc you broke its engagement to interface the frame...rifle? Prob never going to be able to wear one out w reduced loads or loads requiring the cooler powders that we use w cast. point being here is no matter if it's steel coated bullets, copper coated, copper jacketed, or powder coated your prob going to either sell the gun or never be able to shoot that many rounds through the gun.

[M-Tecs]

Good read here http://castboolits.gunloads.com/showthread.php?156622-75-000-Wadcutters-in-a-Model-27

I was the armorer for a State National Guard rifle and pistol team. The round count on some of the 22's was very high. Even higher were some of the 1911's. The 1911 were mostly shot with jacketed. Even with jacketed 45 ACP barrels have a very long life span.

[BNE]

Good read here http://castboolits.gunloads.com/showthread.php?156622-75-000-Wadcutters-in-a-Model-27

I was the armorer for a State National Guard rifle and pistol team. The round count on some of the 22's was very high. Even higher were some of the 1911's. The 1911 were mostly shot with jacketed. Even with jacketed 45 ACP barrels have a very long life span.

Thanks Mtecs, that was a good read...

[Ballistics in Scotland]

Yes, even with jacketed bullets wear by jacket metal is far less of a factor than gas erosion. If it were otherwise it would be greatest near the muzzle, where metal-to-metal movement is fastest. But we invariably see exactly the opposite.

[garym1a2]

good point, I never thought of this, its probaly why rounds like the 243 have a short barrel life.

Yes, even with jacketed bullets wear by jacket metal is far less of a factor than gas erosion. If it were otherwise it would be greatest near the muzzle, where metal-to-metal movement is fastest. But we invariably see exactly the opposite.

[Ballistics in Scotland]

It is, and it is at its worst with high-pressure loads with light bullets and fast powder. Rifles are contrary beasts, and you will get one that breaks just about any rule, but you are likely to get better life with the .244 Remington, which is close to identical but with a fast twist to permit heavier bullets, and therefore is best with slower powder.

[M-Tecs]

It is, and it is at its worst with high-pressure loads with light bullets and fast powder. Rifles are contrary beasts, and you will get one that breaks just about any rule, but you are likely to get better life with the .244 Remington, which is close to identical but with a fast twist to permit heavier bullets, and therefore is best with slower powder.

I disagree. I build NRA match rifles on the side. A .223 shooting 75 to 90 grain bullets has a useable competitive accuracy life around 3,500 rounds in a Krieger SS 7 or 8 twist. Change the bullet to 40 grain in a 9 twist at significantly faster velocity barrel life will at least double.

When first introduced the .244 Rem. was 12 twist and .243 twist was 10. That is the primary reason the .244 failed. http://www.ballisticstudies.com/Knowledgebase/.2446mm+Remington.html

Today 9 and 10 twist are used in both calibers http://www.exteriorballistics.com/reference/pdf/Twist%20Tables_Rifle.pdf

Barrel life is also dependent neck length and vortex angle of the shoulder.

[tiger762]

Lead is an abrasive metal. Feel a powder-coated bullet. Slick as glass. The reduction in friction is like night and day. Someone else mentioned the wear from high velocity exhaust gas. That part will be the same but overall the situation is improved by keeping the lead away from the barrel surface


The last time I asked no one could really answer or did any studies on if pc adds more wear to the barrel then just lubed cast boolits. Has any new info come to light? Thanks.

L. Bottoms

[Ausglock]

My mate works at an indoor range that gets lots of Japanese tourists.
They shoot more rounds than anyone.
The range has a Glock 17 that has over 1 million rounds through it.
The barrel has peened the hood at the back of the barrel and there is no rifling left for the first inch in front of the chamber. The rest of the bore is fine.
This has fired mostly Federal American eagle factory ammo.

[M-Tecs]

Lead is an abrasive metal. Feel a powder-coated bullet. Slick as glass. The reduction in friction is like night and day. Someone else mentioned the wear from high velocity exhaust gas. That part will be the same but overall the situation is improved by keeping the lead away from the barrel surface


Before roller bearings lead Babbitt bearings were state of the art. Babbitt bearings are still commonly used today in a variety of applications. The one I find most interesting is Babbitt bearings are used to on some of the ultra accurate grinding machines since they are more accurate than the best roller bearing we cam make. Lead is used in extreme pressure lubs. Lead is one of the least abrasives metals.

This show some of the alloys and applications http://www.nuclead.com/leadbabbitt.html

[Ballistics in Scotland]

Lead is an abrasive metal. Feel a powder-coated bullet. Slick as glass. The reduction in friction is like night and day. Someone else mentioned the wear from high velocity exhaust gas. That part will be the same but overall the situation is improved by keeping the lead away from the barrel surface

I think M-tecs is right in saying lead isn't an abrasive substance. It is higher friction than some, and such a bad conductor of heat that frictional heat isn't conducted into its internal regions. But that governs what it does to itself, not to the bullet.
.
Apparent smoothness isn't the whole story on resistance to movement of one body against another. Plate glass sliding on plate glass can produce considerable resistance, but ground glass on ground glass slides much more easily.

I got the twist of the .244 Remington wrong, and a fairer comparison might be the 6.5mm. Mannlichers. But speed of powder was among the factors I mentioned. I have a friend who built numerous .25-06 rifles, and reported just what I described by the unwise use of fast powders to produce maximum performance with a light bullet.

[Dragonheart]

To answer your PC question I asked a retired PhD Chemistry Professor from a well known engineering university the question. The professor's specialty was polymer physics. The question was: "Will the Polymer Jacket on a bullet enhance the wear on a gun barrel"? His answer: "Absolutely Not!"

What really wears out a barrel? How many barrels have you ever seen worn out by lead bullets?

It takes a lot of rounds to wear down rifling and long before that the throat of the chamber is long gone due to gas erosion. I personally have fired match 1911's that have had in excess of 40K rounds fired and the guns will still hold a group worthy of competition. Now something like a 220 Swift capable of extreme velocity is different. I have seen barrels in this caliber worn out before the best load was ever found.

[odfairfaxsub]

Deff pistols have a super long life. My thinking is just bc of pistol powders. I compare it to the btu's burning a tissue compared to a rolled up newspaper. The lighter or the bullet is a constant. If bullets wore barrels out then I'd think we would have a 1911 or mp shot out 10k later. Just repeating what everyone said its all about powder. 23 grains of a slow burning/long barrel is going to erode before 4 inch fast powder. Look at 300 blackouts I bet those barrels last long.

least of our worries are bullets. Shoot I've nearly gotten alox lubed cast bullets stuck in my sizer....not a powder coat bullet though. If I put a powder coated bullet on my press and just drop the weight of the handle (if the bullet was previously sized) I believe it would pop through the die on its own accord. There's more resistance in cast bullets lubed. I believe powder coat prob does more to save our barrels than harm. Esp no leading or bullets passing through leading, no powder fouling jamming up our internals, clean baffles, less air borne dust, less lead to hand contact when touching bullets, super slick jackets that swage easy in our presses and barrels.

[Freightman]

Heck wish I could have the time and money to wear a barrel out.

[odfairfaxsub]

Me too. You'll prob have to replace a barrel from lug distortion/shearing/insert other wear wear and tear before shooting the rifling out of most pistol barrels or you'll be in a shoulder surgery prior to shooting a 30-06 out of powder coated

[BossMaverick]

I could see more wear if the powder coat isn't fully cured or if it has abrasive additives for whatever reason. Sticking with gloss PC and cooking the bullets good should eliminate those concerns.

I have more concerns about wear from sand and other impurities in uncoated cast bullets from recycled wheel weight lead.

[fredj338]

Lol, by the time you shoot 20 k from your pistol your going to be obligated to buy a new barrel anyway prob bc your lugs are rounded or bc you broke its engagement to interface the frame...rifle? Prob never going to be able to wear one out w reduced loads or loads requiring the cooler powders that we use w cast. point being here is no matter if it's steel coated bullets, copper coated, copper jacketed, or powder coated your prob going to either sell the gun or never be able to shoot that many rounds through the gun.
Well 20k rds isn't a whole lot for guys shooting in competition. I have a 1911 with almost 40K rds thru it. The match grade bbl is a bit less tight at the bushing but the gun will still shoot well under 2" @ 25yds. I
doubt the poly coating offer much in the way of bbl wear. Certainly less than copper, maybe more than lubed lead.

[leeggen]

BossMaverick if you have fluxed and cleaned the melt you should not have any sand or such in it. All that stuff should be on top of the melt, lead is the heavier and everthing else will float. A barrels actual wear from one end to the other has to be exstemly small. Look how many rounds most of the WW!! rifles and pistols fired. Now those probably did have alot of sand and such in the barrels relative to where the front was fought. That was alot of copper and nickel left behind in the bores.
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