Plated vs Jacketed
- Thread starter akinswi
- Start date
True, pushing wad cutters hard usually does not end well. We have not settles on a bullet style guess i presumed round nose.
2nd response from Faxon. really goof stuff. Based on the cost of ammo, even hand loads, my handgun barrels will probably have plenty of life left in them when i pass them on to my kids. It still makes me wonder though how far lead bullets could extend that barrel life.
one other though I had, is with plated bullets most makers list 1250fps as a max velocity, but I have never seen a jacketed bullet with a velocity listed, other than hollow points for proper expansion ranges. I wonder if it is due to the thickness, or the softness of the plating itself.
"No worries! I'm glad I could at least give some input.
I can certainly see a solid steel core causing that kind of wear, especially on older military barrels and with a cartridge as hot as .30-06. I would be interested to see the test repeated with more modern treatments such as Nitride or Chrome lining. For what it's worth, I have yet to see a barrel get shot out in all of the testing we do. A few of our FX-19 handguns are closing in on 40,000 rounds with no discernable wear on the bore and that is with almost exclusively jacketed ammunition (though all of it was lead core). We have a couple of demo machine guns (5.56) that are closing on 60,000 rounds with normal wear to the throat and gas port. While not as precise as when they started, they are still combat accurate (3-4 MOA) even with the wear patterns. They had a mix of standard copper jacket, M855 spec (mild steel core), and bi-metal jacket ammo through them so we weren't exactly going easy on them.
Based on the bits of info I do know about pistol bullets, the lower pressure and velocity generally mean wear is minimal and the gases behind the bullet tend to be the largest factor to bore erosion. I would hypothesize that a modern pistol barrel with some form of treatment (nitride, nDLC, etc.) should have a lifespan in excess of 100,000 rounds when using jacketed ammunition with a relatively soft core.
I can see the point that there may be some work-hardening happening when the jacket is rolled over the core, but I don't know what hardness exactly the plating or jacket is at. I believe you can usually "choose" what hardness you want a given plating material to be so it could very well be that plated bullets are spec'd to have the same final hardness as jacketed bullets. If the plating and jacket are of equal hardness, then it will come down to the density/hardness of the core material since that will be what the bore is actually working against. This is all fairly far outside my normal bailiwick and not something I consider myself an expert in so please take this all cum grano salis.
Regards,
"
one other though I had, is with plated bullets most makers list 1250fps as a max velocity, but I have never seen a jacketed bullet with a velocity listed, other than hollow points for proper expansion ranges. I wonder if it is due to the thickness, or the softness of the plating itself.
"No worries! I'm glad I could at least give some input.
I can certainly see a solid steel core causing that kind of wear, especially on older military barrels and with a cartridge as hot as .30-06. I would be interested to see the test repeated with more modern treatments such as Nitride or Chrome lining. For what it's worth, I have yet to see a barrel get shot out in all of the testing we do. A few of our FX-19 handguns are closing in on 40,000 rounds with no discernable wear on the bore and that is with almost exclusively jacketed ammunition (though all of it was lead core). We have a couple of demo machine guns (5.56) that are closing on 60,000 rounds with normal wear to the throat and gas port. While not as precise as when they started, they are still combat accurate (3-4 MOA) even with the wear patterns. They had a mix of standard copper jacket, M855 spec (mild steel core), and bi-metal jacket ammo through them so we weren't exactly going easy on them.
Based on the bits of info I do know about pistol bullets, the lower pressure and velocity generally mean wear is minimal and the gases behind the bullet tend to be the largest factor to bore erosion. I would hypothesize that a modern pistol barrel with some form of treatment (nitride, nDLC, etc.) should have a lifespan in excess of 100,000 rounds when using jacketed ammunition with a relatively soft core.
I can see the point that there may be some work-hardening happening when the jacket is rolled over the core, but I don't know what hardness exactly the plating or jacket is at. I believe you can usually "choose" what hardness you want a given plating material to be so it could very well be that plated bullets are spec'd to have the same final hardness as jacketed bullets. If the plating and jacket are of equal hardness, then it will come down to the density/hardness of the core material since that will be what the bore is actually working against. This is all fairly far outside my normal bailiwick and not something I consider myself an expert in so please take this all cum grano salis.
Regards,
"
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I should have expected someone to go read an internet article about Aluminum.
Bending Aluminum past the elastic range (which is small) is not classical work hardening. Aluminum, unlike most metals, has a strain curve that is based on the number of cycles, at any level. Work hardening increases the surface hardness leaving the base subsurface material ductile...and Aluminum does not do that. Classical work hardening occurs when the material has not been pushed into the plastic range.
Bending Aluminum past the elastic range (which is small) is not classical work hardening. Aluminum, unlike most metals, has a strain curve that is based on the number of cycles, at any level. Work hardening increases the surface hardness leaving the base subsurface material ductile...and Aluminum does not do that. Classical work hardening occurs when the material has not been pushed into the plastic range.I think the point of just shoot what works best and buy a new barrel if need be is the way to go . Point being if you shoot 50k rounds instead of 70k rounds does it really matter that you need to spend $100 on a new barrel . Keeping in mind how much it cost commercial ammo or in components to reload those 50k rounds . Every $5k you need to spend an extra $100 , not really a big deal .
Then there’s the whole idea will you even shoot that many in any given gun . I used to think so but collections get bigger and pretty soon your lucky if any one firearm sees 1k a year . If you were talking rifle maybe I’d have a little more concern but handguns I wouldn’t sweat it .
Then there’s the whole idea will you even shoot that many in any given gun . I used to think so but collections get bigger and pretty soon your lucky if any one firearm sees 1k a year . If you were talking rifle maybe I’d have a little more concern but handguns I wouldn’t sweat it .
reynolds357
New member
Heat is the major factor, but metal on metal friction is a factor. Lead can wear steel just like water can wear a rock.
akinswi,
As mentioned above by folks who shoot more than I do, your probably good picking out a particular load, or brand of factory ammo and going on about your business enjoying your shooting.
I myself picked up my first 9mm about 6yrs back. In the 8 months following that I picked up a second and had gone through roughly 9k rounds between the two, based on primer usage, and probably half again that many since. Of those, most were plated, followed by cast, and then jacketed. Both barrels show more wear from the slide, than from the bullets, and that is only a slight wearing of the bluing. I used powders from fast to slow, target type and +P loads, and also ran a bunch of factory in amongst them.
It's not scientific, but they hang in there for quite a while if not overly abused and taken care of.
As mentioned above by folks who shoot more than I do, your probably good picking out a particular load, or brand of factory ammo and going on about your business enjoying your shooting.
I myself picked up my first 9mm about 6yrs back. In the 8 months following that I picked up a second and had gone through roughly 9k rounds between the two, based on primer usage, and probably half again that many since. Of those, most were plated, followed by cast, and then jacketed. Both barrels show more wear from the slide, than from the bullets, and that is only a slight wearing of the bluing. I used powders from fast to slow, target type and +P loads, and also ran a bunch of factory in amongst them.
It's not scientific, but they hang in there for quite a while if not overly abused and taken care of.
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reynolds357
New member
Not doubting them. I will just make the side note that in my years in the court room, I encountered quite a few court recognized legal experts who were dumb as a brick and flat wrong. Arson investigators being the worst. In DNA early days, expert testimony in it was 100% wrong based on what we now know today, especially in areas of how it can and supposedly could not be transferred.When you have a barrel maker that is a member, posting, and is also a court sanctioned ballistics expert.I'm so hurt.
(sarcasm)
reynolds357
New member
All I can tell you about Aluminum is I hate welding it. Its ability to "sink" heat is unbelievable.I should have expected someone to go read an internet article about Aluminum.
Thermal effusivity (a property that describes how fast heat will transfer into a material) of aluminum is about half-again higher than for iron (steel is usually a little lower than iron, especially stainless, which is half that of some conventional steels). But for copper, it is about half-again higher than aluminium. Silver is higher still. So if you want some frustration, try welding to a block of copper (or silver, if you can afford it and your money is just burning a hole in your pocket).
Lead actually won't wear down steel in the same way water wears rock. A lot of rock wear by water happens because water actually dissolves rock minerals from its surface over time, and lead can't dissolve steel in the solid state. One wear factor the two do have in common, though, is the ability of both water and lead to move grit against a harder material. Lead is able to hold grit against steel, while water bangs grit against a harder surface more randomly, so lead is the better lap, normally. Firelapping is just doing this on purpose. But if you shoot lead bullets for non-lapping purposes, you will get best barrel life by keeping them clean.
Lead actually won't wear down steel in the same way water wears rock. A lot of rock wear by water happens because water actually dissolves rock minerals from its surface over time, and lead can't dissolve steel in the solid state. One wear factor the two do have in common, though, is the ability of both water and lead to move grit against a harder material. Lead is able to hold grit against steel, while water bangs grit against a harder surface more randomly, so lead is the better lap, normally. Firelapping is just doing this on purpose. But if you shoot lead bullets for non-lapping purposes, you will get best barrel life by keeping them clean.
4Amp says a rifle barrel used entirely in slow fire will last X,000 rounds before wear begins to affect its performance.
I'm not aware of any 26 or 28 caliber magnum lasting more than 900 rounds in long-range matches, My 264 Win Mag lasted 640, two 30 caliber magnums went 900. All slow fire.
I'm not aware of any 26 or 28 caliber magnum lasting more than 900 rounds in long-range matches, My 264 Win Mag lasted 640, two 30 caliber magnums went 900. All slow fire.
I said that, and used "X" as the number because there is no way to predict the actual number accurately due to the many, many variables involved.
And here's where those variables really show up. Sometimes, the "X thousand" round number can be less than 1.
First question I would ask is what was your criteria for "used up" that was met at less than 1,000 rounds by those big overbore magnums???
There's a significant difference between what a serious match shooter considers "no longer good enough" and what the annual deer hunter does. I've got a .308 Win that has about 4,000 rnds (pretty much all slow fire) through it give or take a few, and its still delivers minute of deer accuracy.
I'm sure a match shooter would consider that barrel worn out and not good enough to win matches, and they'd be entirely correct about that, from their specialized point of view, but that barrel isn't worn out to the point where it no longer does the job it was made to do. Not even close, actually.
308 Win tests done by Kevin Thomas at Sierra in the late '90s wore out chrome-moly barrels at 3000 rounds and SS at about 3500 rounds. These were barrels in Remington actions mounted to a test bench and fired in Sierra's indoor test range. The criterion was watching for a flier to appear and afterward confirming that fliers were now starting to occur regularly to confirm that the first flier wasn't just an outlier.
That's what happened when my M1A's first barrel went out, too. I was cleaning a slow-fire target in a match when I got an uncalled nine at about 10:30. At first, one in 20 did that, then it became 1-in-10, then 1-in-5. Basically, it took a 0.75 moa rifle and made it a 1.75 moa rifle if I took the halfway point between its original group center and the fliers as the new POI. Fine for deer and combat shooting, but just not a target rifle anymore. That did happen somewhere just past 3000 rounds.
That's what happened when my M1A's first barrel went out, too. I was cleaning a slow-fire target in a match when I got an uncalled nine at about 10:30. At first, one in 20 did that, then it became 1-in-10, then 1-in-5. Basically, it took a 0.75 moa rifle and made it a 1.75 moa rifle if I took the halfway point between its original group center and the fliers as the new POI. Fine for deer and combat shooting, but just not a target rifle anymore. That did happen somewhere just past 3000 rounds.
Big bottleneck cases holding lots of slow burning powder jetting out through relatively small bore size driving heavy for caliber long skinny bullets through tight twist barrels .... Yup. Heat and gas and powder particulants do cut steel.
Using identical bullets,a 308 barrel will outlast a 300 Win Mag barrel. I'd bet the US military has data on that concerning sniper rifles.
At some point,the "fire" is the predominant wear factor. It might be "How many pounds of powder can the throat handle vs how many bullets."
Is there abrasive grit in a primer?
But with 22 Rimfire, or 38 spl or other lead bullet,powder stingy target loads..
"Cleaning" might be the biggest wear factor,
I have machined a lot of graphite EDM electrodes. Graphite will dull high speed and carbide cutters .
Graphite is present in both burn deterrent and some bullet lubes. OK,graphite comes in various forms.
But I have seen some gritty,nasty powder fouling from ball powders.
And yes,its true! We think the softer metal would not wear the harder metal.
But a softer metal WILL embed grit. Each speck of grit is a cutter tooth. That is the principal of the "Lap". I have polished a lot of mold steel using cast iron or brass or copper ,even wood to embed and drive abrasive grit.
Your brass or aluminum or even plastic coated cleaning rod,or dirty bronze brush can cut your barrel steel.
Using identical bullets,a 308 barrel will outlast a 300 Win Mag barrel. I'd bet the US military has data on that concerning sniper rifles.
At some point,the "fire" is the predominant wear factor. It might be "How many pounds of powder can the throat handle vs how many bullets."
Is there abrasive grit in a primer?
But with 22 Rimfire, or 38 spl or other lead bullet,powder stingy target loads..
"Cleaning" might be the biggest wear factor,
I have machined a lot of graphite EDM electrodes. Graphite will dull high speed and carbide cutters .
Graphite is present in both burn deterrent and some bullet lubes. OK,graphite comes in various forms.
But I have seen some gritty,nasty powder fouling from ball powders.
And yes,its true! We think the softer metal would not wear the harder metal.
But a softer metal WILL embed grit. Each speck of grit is a cutter tooth. That is the principal of the "Lap". I have polished a lot of mold steel using cast iron or brass or copper ,even wood to embed and drive abrasive grit.
Your brass or aluminum or even plastic coated cleaning rod,or dirty bronze brush can cut your barrel steel.
For hitting human torso size target, that's quite adequate. I thought snipers in combat hardly have chance to do follow-up shots, as the target would run or hide. It turns out they mostly freeze in confusion.
Time has passed. With today's advanced technologies, this sort of accuracy has become almost a walk in the park. I wouldn't be surprised computer will soon take up the task of aiming according to the firing solution based on the real-time environmental conditions. Human just greenlights the shot. Even guided bullets are not too far fetched.
-TL
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