Powder choice and barrel life

[rollmyown]

What are your thoughts on powder choice and barrel life? Does burn rate and burn temperature have much impact on barrel life/throat erosion. I know that cordite burns very hot and caused major problems with metford rifling when the 303 British transitioned from blackpowder.

So the question is what burns hot and what burns cooler. Are single base powders better than ball powders etc.

Does smokeless powder use in a blackpowder designed rifle have a protective efect? (A Trapdoor springfield comes to mind).

mmm interesting...

[Crusty Deary Ol'Coot]

Well, just an Ol'Coots opinion, but ---------------------------------------

Unless you set out to "shoot out" a barrel, such as sustained high rate of firing with high intensity rounds, say for example a 257Weatherby or??, shoot at a reasonable rate of fire and just don't worry about it.

Barrel gets hot, let cool off.

I used to worry about that, but have come over the years, and having never shot out a barrel, to the place where I figure if I am lucky enough to shoot out a barrel I will have done a great lot of shoot'in and should consider myself very lucky indeed!!!!

I have a RUGER M77, "flat bolt" in 243win. A friend bought the rifle, "used" back in the late 60s or early 70s and it has always been a great shooter.

My wife bought me the rifle when it came up for sale in probably the late 70s, and because of that fact it would probably get rebarreled, if and when it ever gets to the place where it will no longer shoot MOA.

Being as how I lately have been testing 55gr Nosler Balistic tips in the 3700 - 4000fps range, I suppose it is a possiblity I will shoot out the barrel.

However, that rifle has given a lot of pleasure to at least 3 owners and done so over a lot of years, so it doesn't seem like a new barrel would be any big thing.

Keep em coming!

Crusty Deary Ol'Coot

[wiljen]

1.) The more overbore the cartridge is, the less time your barrel is going to last regardless of powder choice as throat erosion is going to take its toll. So buy the least cartridge that suits your purposes. If you need a 300 Savage, don't buy a 300 Ultra Mag simple economics.

2.) With mid sized rounds (30/30, 308 etc) if you don't intentionally light up a barrel with rapid fire shooting, and you give the barrel time to cool, you probably wont ever have to worry about which powder you use as it will make little difference over the life of a barrel.

[madsenshooter]

I've been using Blue Dot in my Krag rifle. When I first started, the bullet I was using would just touch the lands when I was at maximum magazine length. Now it has to be seated out .030" beyond max mag length to touch. That's in about 300 rounds. We've got two factors working here though. One, Blue Dot is a high nitroglycerin (20%) double based powder that burns hot. You can see the heat on some of the case mouths, they start to take on a color similar to being annealed. The second factor is Krag barrel steel. I don't think the formulation will take the temperature. There's no nickle in it. I'm going to shoot it as long it shoots good though, comforted by the fact that the CMP is selling new chrome-moly barrels. For longer barrel life, rollmyown, stick with the single based powders, they do burn cooler.

[rollmyown]

Thanks for the input. I thought this question was going throught to the keeper for a while. The question was mainly about preserving the barrels in our older cherished rifles, - I'm not too worried about rebarreling a modern CZ or Ruger etc.

Much appreciated.

[c3d4b2]

Here are three articles on erosion studies.

http://www.riflebarrels.com/articles/barrel_life1.pdf

http://www.riflebarrels.com/articles/barrel_life2.pdf

http://www.riflebarrels.com/articles/barrel_life3.pdf

[chasw]

Some reloaders believe that throat erosion is more pronounced with slower burning powders. The idea is, fast powders like Bluedot are largely burnt up before the bullet leaves the case, while slower numbers like H4831 continue burning progressively while the bullet is traveling down the bore, thereby exposing the throat and first few inches of the bore to more heat than the faster powders so. Makes sense to me, however, no one knows for sure what happens in those first few milliseconds of interior ballistics. - CW

[mroliver77]

I have come to the conclusion that ALL shooting and ALL boolit and powder types are bad for your gun. I cringe when I read of guys that shove a cleaning rod down their barrel EVERY time they shoot it! That just cannot be good for it!
Jay

[Crusty Deary Ol'Coot]

In fact, the rapid passage of boolit and powder down the barrel is sooooo damaging to the quality/life of a barrel, that it would be wise if'n we'd all hang em up and never shoot em again.!

Plus the fact that all that lead fly'in around and the smoke and powder residue induced into the air is a real health hazard, gag gag cough gasp gasp weeeeeeeze.

If'n I can make it home again go'in ta need to get a new hobby!

Sob sob gasp weeeeeze the damage I've caused to the greenie's enviroment drives me to the ground with shame!

Ol' Al Gord probably has a contract out on me, preferably, "dead".

Keep em coming!

Crusty Deary Ol'Coot

[EOD3]

In a previous life, we found that nitroglycerin propellants caused greater erosion than non-nitroglycerin propellants.

[Jack Stanley]

When I was using the model twenty-nine in compitition I used moslty wadcutters and a mild charge of Bullseye . Currently the frame is holding it's third barrel and cylinder I don't have a total round count the gun has seen but I was using more than a case of primers a year for over ten years . I read somewhere that Bullseye and Unique had somewhere around twenty-seven percent Nitroglicerin but I don't know .

I use a lot of Unique and Universal Clays in rifles but I haven't worn a barrel as bad as the old wheelgun was . Now that I'm shooting the rifles more , I will find out soon enough if all these high-nitro powders are gonna eat the barrel or not . Truthfully ........ I can't say as I really care what Algourd thinks about it , he didn't show much thought about it every time air force two went up in the air .

I don't generally heat the barrel hotter that what you'd want to touch . I think that all the greasy , waxy lubes we use tends to negate the eroision some but I can't prove it and I ain't gonna try .

Jack