I’m curious how MUCH of a difference the following make as far as durability.
I know hammer forging beats out button, but by how much?
I know polygonal beats out rifling, but by how much?
Got any stats on any of these to put them in perspective?
[ul]
[li]Cold Hammer Forged vs. Button[/li][li]Polygonal vs. Rifling[/li][li]Stainless vs. nitrided 4150 cmv[/li][/ul]
EDIT: I know there are a ton of old threads on this but I can’t find any quantitative data. e.g. 20,000 rounds to key-holing for rifling vs 30,000 w/ polygonal.
It makes NO difference because the chrome lining doesn’t really care what steel is underneath it.
If you’re after accuracy, it makes NO difference because you’re after accuracy.
Nobody knows and nobody can tell the difference. Manufacturers price one or the other higher and perceived value will dictate which one an individual will buy.
Cold hammer forging increases barrel density, and increased barrel density does prolong the life of the chrome lining. Think of a house built on a stronger foundation. The chrome adheres to a more dense surface and is less likely to detach. Other benefits to hammer forging is that it works out imperfections in the barrel blank which improve accuracy, overall durability, and makes the chrome surface more uniform. When the imperfections are worked out of the barrel, the chroming process is more thorough and uniform. It really is the best barrel combination of high volume shooting, durability, and accuracy. Not as accurate as a non chrome-lined match barrel.
CHF is implied to give advantages in longevity and accuracy but I believe the CHF barrel thing in AR’s is mostly hype. sure there may be theoretical differences but no one has been able to quantify those differences that I have seen. ymmv…
This makes me a believer in theory, but I would love quantitative numbers:
Hammer forged barrels have no "chatter" like button rifled ones. My noveske doesn't even hold enough copper to turn bore cleaner blue. That's what made me a believer. Beyond that? I don't know.
3rd: I’m also interested in quantitative differences between rifling types.
Because there isn’t any. There are no scientific tests to prove exactly how many rounds the barrel will last longer, how the barrel will warp less, and which ones are better.
This has been covered many times. Sure people have run many rounds through each, but there has been no crazy in depth tests on this, and using the search button will show this as it’s been disgussed many times. People are just looking for answers to questions that just are not important enough for crazy in depth research to be done.
Outside of that, the accuracy side of things have been covered, but durability/round count is still undecided. In the end who cares, barrels are disposable parts in the grand scheme of things. It will take how many thousands of dollars of ammo to shoot out a barrel… so in that regard, the barrel and even BCG are so small in cost that the question in general IMO is worthless. Shoot the hell out of it, shoot it out, replace it. Nuff said.
That doesn’t really show anything though, asides from the filthy 14 that lasted a gazillion rounds. Not a comparison, and doesn’t prove anything, other than a BCM standard barrel lasting a long arse time.
Yup. If I recall, wasn’t DD going to do a big ordeal about their HF barrels? Still would have been nice if they purchased a few competitors and did a test along side of them. (this test was mentioned on T.TV).
The problem is that throat erosion is going to be dependent upon both how many rounds are fired and how rapidly those rounds are fired. There is not a definitive number because the manner in which the rounds are fired is a critical component of barrel life. You can make a lower quality barrel last longer and tear up a higher quality barrel faster by simply firing less rounds per minute or more.
Barrels are an expendable component. You will spend many multiples the cost of the barrel by buying ammo before you’ve “shot out” a barrel from any respected manufacturer. Is there a particular reason you’re concerned, or is this simply a question for the sake of learning the science of barrels?
The question could be will you ever see the difference in how and what the barrels are made of. I would look in to the quality. Stainless is softer. A high quality of either will be better than a low quality of either. As mentioned the filthy 14 how much better do you need than that. Maybe if you get into full auto and burn through thousands and thousands of rounds you could see a difference. Quality always wins over razzel dazzel.
Yes but as was said above, the rate of fire is going to have a massive effect on barrel life. In the lucky gunner test they talk about the rifles getting so hot they couldn’t hold them, the average person is not going to burn through 10k rounds that fast.
Heating the barrel steel up to the point of elasticity and then continuing to pour bullets through it is going to tear up any barrel and I don’t think the lucky gunner test can really be used as a measure of barrel life, except under rapid fire conditions.
No doubt, my point was that I would expect the same amount of life from a button rifled Colt barrel as I would a FN CHF barrel if both were fired like Andrew and his people did.