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Posted: 4/12/2007 8:32:32 PM EDT
| Would someone please explain the difference, and attributes. |
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I'm sure someone can give you a much more complete description of what the difference is and the effects of each, but since I've been considering a build I'll tell you what I have read, not what I have experience. From what I can gather Chrome lined are the longest lasting then Chrome Molly followed by stainless steel. As far as accuracy goes its the opposite, stainless is the best followed by chrome molly then chrome. There are some people who say that 95% if people will never shoot good enough for the difference in accuracy between the barrels to be noticeable and there are people who will say they will all last about the same. Lasting is of course a relative term decided by how accurate you need to be, the more accurate the less it takes to wear the barrel out. As for the difference, chrome is chrome lined, basically the barrel is made out of steel and then the interior is plated with chrome, while chrome molly has the chrome alloyed into the steel. If I have my stuff wrong someone feel free to correct me. |
That question has been asked on this forum dozens, if not hundreds of times since I started coming here. It has never been answered, and it likely won't be. The reason is simple. There are many variables in barrel life, and to get a meaningful answer would require shooting to destruction of barrels under many different conditions, using multiple barrels each time to ensure statiscally sound results. It would take dozens of barrels, hundreds of hours and hundreds of thousands of rounds to generate the data. The only people with the resources to do that aren't interested in semi-auto shooting. You might get a few anecdotes from the tiny handful of people who have actually worn out a barrel or two. Their usages will be too varied and their sample size too small to mean much. They will give you answers between 3000 and 40000 rounds. |
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To answer your question directly, the difference is in the steel vs in the coating. Chrome-moly steel is a type of steel e.g. mild vs chrome-moly vs armor plated. It refers to the chemical and structural properties of the steel. These are influenced by adding chrome to the steel mixture to make is harder. Barrel steel is generally a chrome-moly type of steel. Chrome-plate is the coating applied to steel. Like what you have on your bumper (for you young guys, they use to be chromed metal rather than colored plastic). Chrome plating can be applied to virtually any ferrous metal. You can chrome-plate mild steel as well as armor plated steel. Now that you know what the difference is, you'll likely ask why. Chrome-moly steel is a popular steel to use in barrel making as is stainless steel and others. It has a good combination of hardness (to remain straight and resist wear) while still being soft enough to reliably and effectively machine to add the rifling to the inside of the barrel. Chrome-plating is a popular coating applied to barrels after they have been machined it (including adding the rifling to the barrel) to give them a much harder surface to resist both bullet wear and ablating from the burning powder and resist rusting and pitting from oxidation. Bottom line the metal ‘chromium’ is used in both processes. In one it becomes part of the steel and adds to the physical properties of the steel itself and in the other it is a coating on the steel and adds physical properties to the surface of the steel. |
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To add to the above post, the Bushmaster catalog clearly states that they "chrome plate" the bores for wear resistance, of their "chrome moly barrels". Somewhere in this site is documentation of a test where someone was paid to run a durability test on a non-chromed (plated) Colt HBAR. My recollection is that it ran about 10,000 rds before it was declared "shot out" meaning the bullets were key-holing. The author also admitted they had run the thing pretty hard, shooting continuously until the barrel was smoking. Whether that made any difference...??? |
That article was in an edition of Shooting Times magazine about a decade ago. The gun was key-holing with the ammo they had in large quantity somewhere after 9000 rounds, but it still shot okay with another brand. I think they shot all 10,000 rounds over one weekend. The gun had no parts failures of any kind. |
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