Any detrimental effects on bore from using aluminum for GC's

[Patrick L]

I'm not trying to stir anything up here, but I was wondering if anything really scientific has been done to investigate this?

Also, if you're anything like me, you do things (cast boolits, reload ammo, etc.) WAY ahead, and in some cases these things sit on a shelf for years before you actually get around to using them. I was wondering, lets say you made a few thousand aluminum checks and didn't use them for a year or two. Then lets say they got all oxidized like aluminum can get. Would it be advisable to still use them?

Just wondering if anyone has any real experience with this stuff?

[felix]

Aluminium is naturally black. Any other color means it has oxidized (or been modified), and it does so very, very rapidly in any natural circumstance. So, you never see black aluminium. ... felix

[edsmith]

I have some alu. flashing that I have had for at least 8 years, it looks like it did when I bought it. if some alu. checks oxdizes in a few years, you have a envirment problem. if you think alu. is going to give you problems, spend the bucks and go with copper.only thing is, copper will corrode a lot faster than alu. I think gold would be the best check material, but if you are like me, you don't have any gold sheeting laying around. wonder what a 30 cal. check would cost.

[Blammer]

gold GC's huh? give a real reason to 'mine the berm'

[mold maker]

Heck,,,Pure gold is just a little harder than soft lead alloy. Why gas check when ya can just cast gold Boolits.
As much as my wife says I spend on guns and support stuff, I might as well go all the way.
Boolits at $800. / $1000. each would require lots less reloading and gun cleaning.
I might actually be PC and stop shooting all together, but I'd be glad to clean your bore for free.

[Dannix]

Aluminium is naturally black. Any other color means it has oxidized (or been modified), and it does so very, very rapidly in any natural circumstance. So, you never see black aluminium. ... felix
Huh? Al is metal. Like silvery. Like, you know, metal. Not sure where you're getting 'naturally black' from...you thinking of bauxite or something?

[30CAL-TEXAN]

Huh? Al is metal. Like silvery. Like, you know, metal. Not sure where you're getting 'naturally black' from...you thinking of bauxite or something?

I think bauxite is red. I'm no expert but I visited an Alcoa plant once that processed bauxite and everything there was covered in red dust.

[Dannix]

I was trying to give him an out.

Way to ruin it.
:kidding:

[30CAL-TEXAN]

I was trying to give him an out.

Way to ruin it.
:kidding:

Sorry! My bad. Please disregard the previous comment.

Let's try this again.

"Yea, must be bauxite or something!"[smilie=s:

[legi0n]

Here's a thread about aluminum jackets. Draw your own conclusions
Aluminum jackets (http://www.thehighroad.org/printthread.php?t=463774)

[edsmith]

I thought we were talking about gas checks. differant critter.

[RP]

I know this may be off track but anyone know anything about the use of alum GCs and if they oxide would it cause a problem.

[30CAL-TEXAN]

I know this may be off track but anyone know anything about the use of alum GCs and if they oxide would it cause a problem.

That's not really off topic at all. It is the point of this thread....I guess we just found our way off target for a bit.

[longbow]

I'm curious too.

Aluminum does oxidize extremely rapidly but natural oxidation is not quite like anodizing as some compare it to. Anodizing forms a thick, hard evenly coated surface where natural oxidation is more powdery ~ in my experience anyway.

- Aluminum oxide is very hard indeed but is there enough and coarse enough to damage a barrel when formed naturally?
- Has anyone shot enough rounds checked with aluminum checks to even comment with some authority? This would have to be thousands of rounds through one barrel.
- My feeling was that the oxide is scraped of during forming and sizing then again during seating in the cartridge but as Patrick L points out, some cast, check and size long before loading so does enough oxide form in storage to harm a barrel?
- Does a coating of lube prevent re-oxidation?

I ask out of curiosity as I am using and plan to continue using aluminum gas checks. If I wear out a barrel I guess I will have the answer if someone doesn't come up with one sooner.

Longbow

[RU shooter]

I see alot of empty soda and beer cans laying for years along the road side that still look like new inside and out? Same with the aluminum painted flashing on my house. Those are what my chex's are made from.


Tim

[Tom W.]

Lignite is black/ brown. Bauxite is a light tan color to almost white, and when it's dried it's what men would call white. It comes from kaolin clay. Ever taken some Kaopectate?

[RP]

well I think that just about settles it alum is just as good as brass or copper now any ideal on whats the natural color of alum most i see has labels on it ? I sure hope that has helped you out Patrick.

[edsmith]

Ricky P ,that is one cool avatar :)

[Uncle R.]

Bare aluminum forms an oxide skin almost immediately. The skin seals it from the air and prevents further oxidation. That's why your aluminum boat or storm door or lawn furniture will last for years showing little or no corrosion. Aluminum flashing is probably anodized or finish coated when you buy it.

[Colt .45]

As a bump to this. To those who believe that alum is bad for your barrel, do you think painted aluminum is any better?

[legi0n]

I doubt it. Painted aluminum GCs will still leave thin layers of fouling on the bore and these thin layers will oxidize instantly.
Now the million dollars question is how harmful such a fine abrasive is?
Guess we'll never know.

[Jim Sheldon]

I doubt it. Painted aluminum GCs will still leave thin layers of fouling on the bore and these thin layers will oxidize instantly.
Now the million dollars question is how harmful such a fine abrasive is?
Guess we'll never know.

I suspect that they won't be any more detrimental than shooting copper washed, steel jacketed bullets through the bore. The Russians and Germans did it through much of WW2 and considering the number of rounds fired, and bore condition of the large crop of imported Mosin's and Mausers, I ain't gonna even worry about it.

I've got a gas check making die on order for my 8mm mauser and I already have a 50' roll of Amerimax aluminum flashing on hand to start making aluminum checks with as soon as the die gets here. At my age, (68) I don't think using AL checks on my cast boolits has a chance of wearing out the barrel on my 98K before I wear out and have to stop shooting it.

Jim

[JIMinPHX]

I've used aluminum gas checks in a 30-30 with good results. I tried them in a rifle that had a chrome bore & they made a horrible mess that took a long time to clean out.

[JIMinPHX]

I just skimmed that High Road post. I see that some people there don't think that aluminum is ductile enough. The picture in post #134 of this thread shows my results.

http://castboolits.gunloads.com/showthread.php?t=45542&page=7

They looked to have been plenty ductile if you ask me.

[35 Whelen]

So aluminum will oxidize and wear steel.... I personally have never seen aluminum oxidize...I know it does, but I've yet to see it. But let's think about this rationally.

Exhibit #1- Soft drink/beer cans. Has anyone actually seen one of these that has oxidized? I know I haven't.
Exhibit #2- Those aluminum Garage Sale/No Trespassing signs (my preferred gas check material). I've seen age-old ones hanging on fences and they look normal to me.
Exhibit #3- Aluminum BULLET MOULDS. I have several Lee's, some going on 20 years old, as well as an NEI, an LBT, and an NOE. None show any signs of oxidation. But for the sake of argument, let's assume they have oxidized. This would mean they'd wear out the STEEL (same material that barrels are made of) sprue plates. My experience has been the exact opposite; the steel sprue plates wear out the tops of the mould blocks. Also, wouldn't the aluminum wear out the alignment pins?

I personally have fired well in excess of 1000 aluminum checks in about three .30 caliber rifles. My K-31 with which I compete, a Savage No.4 Mk.1 and an 03A3 that's been turned into a competition rifle. In fact I fired 15 rounds through the 03A3 last night and another 15 just tonight. This particular rifle routinely groups 5 shots under 1.5" @ 100 using the aluminum checks.

All the rifles shoot just as well as they did the day I acquired them.

35W

[cast367]

in the very past I have seen aluminum jackets in 9mm luger.
It was a German war production from 1944.
The berdan primers where aluminium . Cases Steel, like the entire ammo production in Germany.

[felix]

I doubt if anyone on this board has seen raw aluminum. ... felix

[BruceB]

Felix, ol'man....never say never!

A sister local of a union I belonged to in the NWT was the bargaining unit at a huge aluminum smelter on the northern coast of British Columbia. There was a fair bit of visiting back and forth, despite about 2000 miles of separation between the locals.

I dare say that I've seen some thousands of tons of "raw aluminum", including its initial molten state. Just HAD to put a little tug on yer chain, pard...

[felix]

Bruce, did you see the aluminum being made in a vacuum chamber? Any hint of oxygen makes the aluminum silvery white. In other words, you see a coating when you see aluminum. The underlying aluminum can be almost absolutely pure (lab grade). Think of the raw sodium you have seen. It was covered with an oily substance, right? Otherwise it would have caught fire with the moisture in the air. ... felix

[legi0n]

I personally have fired well in excess of 1000 aluminum checks in about three .30 caliber rifles. My K-31 with which I compete, a Savage No.4 Mk.1 and an 03A3 that's been turned into a competition rifle. In fact I fired 15 rounds through the 03A3 last night and another 15 just tonight. This particular rifle routinely groups 5 shots under 1.5" @ 100 using the aluminum checks.

All the rifles shoot just as well as they did the day I acquired them.

35W

Now that's one piece of proof that aluminum GC abrasion is insignificant.

[Dannix]

I've seen raw Na just to see it in undergrad lab. Guess what, it looks metallic. :mrgreen:

One question it ask, if there was trace aluminum oxide being left in your barrel, and each shot there after contributing to some level of firelapping, is what 'grit' equivalent is the aluminum oxide. I'd have a hard time getting excited about, say, 3k+ grit, while on other hand 100 grit would get me quite excited. Thoughts?

[Tom W.]

Bauxite is about as raw as aluminum gets.... I used to mine it.

[longbow]

To my knowledge, unprotected aluminum oxidizes very rapidly forming a protective skin that inhibits further oxidation. There is no question that aluminum oxide is hard and abrasive.

The question as I see it is kind of three part:

- as Dannix says, if the abrasive is fine enough, does it matter? Let's face it we get barrel erosion from burning powder. Are we going to stop shooting because burning powder wears out our barrels?
- when the check is formed, and sized, and lubricated the surface is scraped "clean" so is there enough abrasive left and coarse enough to worry about? And the lubricant coats the aluminum so is more oxide even formed?
- after you pull the trigger, the boolit is pushed out of the cartridge which produces a wiping of the check so is there enough abrasive left on the check to matter?

Okay then I guess there it is more than a three part question.

This is much like the argument that paper patching is abrasive to the bore.

I guess my standpoint is that I plan to shoot both aluminum gas checks and PP boolits and see if I wear out a barrel.

If I do then I will have learned a lesson and the cost will be a barrel.

Longbow

[JIMinPHX]

I doubt if anyone on this board has seen raw aluminum. ... felix

Does the black aluminum powder from Germany, that is used as a precursor to thermite, count?

[geargnasher]

Now I'm confused. I've TiG welded aluminum for years and it looks silvery even in a molten state inside an argon bubble. At least that's the way it appears to me. It does oxidize the INSTANT the shielding gas is removed though, making that familiar dull surface. In extreme cases aluminum, or at least aluminum alloys, will form white powdery crud on the surface and that's the stuff to watch out for. They make sandpaper out of it.

As far as the soda cans and aluminum flashing, aluminum signs,all that stuff is either painted, anodized, or coated with a clear oxygen barrier to keep it shiny.

As for shooting it, unless the checks are severely oxidized, I can't say it would really be worth worrying about. If it was, somebody would know by now.

Gear

[pistolman44]

I'll start using aluminun gas checks when the major manufactures start to make gas checks out of aluminum. I did buy one of those Freechex II tools for a 44 but after thinking about it I sold it the 1st month. I'll only use them if I pick up a cheap gun and don't care about the barrel life. They may be ok but it would have to be proven beyond a doubt for me.

[Wally]

I researched this some---after aluminum is exposed to air it oxidizes in micro seconds with an aluminum oxide coating that is 4 nanometers thick. 4 nanometers is quite miniscule--- 0.0001574804 inches thick.

If aluminum gas checks were abrasive I should think that before too long the tool used to make them would wear out.

[Dannix]

http://www3.wolframalpha.com/Calculate/MSP/MSP7319bec6aaeh5ad80f00005i23dc69h5945a0f?MSPStore Type=image/gif&s=2&w=332&h=106

http://www3.wolframalpha.com/Calculate/MSP/MSP3319bec6aaeh28bf7c000053a6h76ig6ach75g?MSPStore Type=image/gif&s=2&w=147&h=38
I'm really rusty on my chemistry, but only london/van der vals/dispersion forces is the only intermolecular force for these guys, yeah? I think geargnasher may be on to something concerning Al alloy being the source of sandpaper. Al2O3 (I never did learn inorganic nomenclature) would be mighty fine stuff.

Oh, here we go -- put a little cooking oil on paper towel and wipe cookie sheet. The gray on the paper towel is Al2O3. This is why I don't use Al cookware, incidentally, but it should also underscore how fine this stuff is.


I can't find any material on how different grit sizes are made. I did discover though I I'm probably using silicon carbide for wet/dry stuff. Always something else out there to geek out about...

[mold maker]

I think this is relative to this discussion. Found it in an Email about the wart hog aircraft that has made such a difference in Iraq, Afghanistan, and Pakistan. Turns out that the gun was developed first and the plane built around it.

(Quote)
The bullet for the 30x173 Avenger has an aluminum jacket around a spent uranium core and weighs 6560 grains (yes, over 100 times as heavy as the M16 bullet, and flies through the air at 3500 fps (which is faster than the M16 as well).

The gun shoots at a rate of 4200 rounds per minute. Yes, four thousand. Pilots typically shoot either one- or two-second burst which set loose 70 to 150 rounds. The system is optimized for shooting at 4,000 feet.
(Quote)

Now if the above is true, what do we have to fear about a tiny gas check skirt, fired one at a time, at the velocities we shoot cast at? I think this pretty well covers the subject.

[Phil A]

Found this article. http://www.exteriorballistics.com/reference/rifleinout.cfm Interesting to consider that the cast bullet alloy could be a bigger issue than the aluminum gas checks. However throat erosion from high pressure loads when shooting "full length" copper gas checks is what really kills barrels. - Phil


Bullet friction, as it pertains to barrel wear, is frequently a topic of discussion among shooters. While this friction causes some wear, it is the least measurable factor in barrel life. In Small Arms Design Vol. II, Col. Townsend Whelen mentions a Springfield 22 rimfire barrel that had been gauged when it was installed, and again after having fired in excess of 80,000 rounds. A uniform wear of .0004” was observed throughout the length of the bore, undoubtedly caused by bullet friction. Granted, this was referring to lead bullets, not jacketed. However, when we consider that most centerfire barrels are completely shot out due to throat erosion in less than 10,000 rounds, bullet friction becomes utterly meaningless as a factor in barrel wear.

There is perhaps one situation where bullet wear may pose a problem —poorly made lead bullets, cast from dirty material. If the dirt and grit commonly found on used wheel weights and other sources of scrap lead is not removed by frequent and thorough fluxing, it will be cast into the bullets. Any grit exposed on the bullet’s bearing surface will act as an abrasive lap. This situation is easily preventable, simply by using some common sense and good casting techniques.

[PatMarlin]

And- throat errosion is no big deal for a cast shooter. We simply adjust our cartridge to fit.

Shazzam... problem solved Monica... :mrgreen: