Aluminum Oxide a Problem?

[fishhawk]

what may be possible for the 2 gun test may be a handi-rifle with 2 of the same barrels (308?) but either way it would be a long drawn out test. another thing that may be a influence could be velocity pushing a 31141 out of a .308 with 10-11 gr of reddot may do nothing but a charge of 40 gr of BLC2 may be a whole different problem if you got the velocity up to the 2000 fps range. so there's another thing to consider

[tjones]

WOW! What the chart shows is that in galvanic reactions with iron and aluminum is about ten time less than that of copper or brass.

WHAT A FIND, GREAT RESEARCH. tj

[Jeff H]

Here is a METALS GALVANIC COMPATIBILITY CHART that shows the values of dielectric reactions between various dissimilar metals.

Thanks, Jim.
As an engineer and project manager for an OEM, I have had customers claim that galvanic reaction was causing percieved problems where it might have been a problem had it not been for the conditions under which two dissimilar metals were in contact. As a carpenter, I have removed mix-n-match aluminim gutters with steel fittings and fasteners where the crust tha formed looked as if it could grow legs and crawl away. Depending on the conditions and evironments, I have seen either no affect or extreme affects but have never been smart enough to figure out which conditions contributed positively or negatively either way.

what may be possible for the 2 gun test may be a handi-rifle with 2 of the same barrels (308?) but either way it would be a long drawn out test. another thing that may be a influence could be velocity pushing a 31141 out of a .308 with 10-11 gr of reddot may do nothing but a charge of 40 gr of BLC2 may be a whole different problem if you got the velocity up to the 2000 fps range. so there's another thing to consider

Exactly! And exactly what I had hoped to not have to do. Someone out there must already know what the results will be - whether that someone is among us is still in question. We percieve as we make our own observations and it seems none of us has actually percieved any startling evidence. We hypothesize based on our prior knowledge and act according to good judgement. Neither is anything approaching superstition but neither is as definitive as the test you suggest - which would be the only way to nail it down for sure, unless someone else has done it - within the context of firearms or another set of similar conditions.

I am not up for the test myself. I don't see yet anything that scares me enough to make me feel it is necessary for the level of curiosity or concern among us collectively. I am certain I have not used enough of them to date to notice anything significant and may never, but I am sure there are many here who shoot much more than I. My shooting/reloading/casting habits have evolved from being measured in thousands of rounds to tens of rounds and when I see something new, I enjoy the collective wisdom of those here who are contributing more to the cause by expending more of their time and ammunition. Certainly, the varying perspectives and experiences are a wonderful resource.

In the meantime, it seems many experienced people see no issue but some have expressed seemingly valid reservations. I'll watch the two I am using and see how things go. Not the most perfect test, but if it affects what I am actually using then it concerns me most, so that's probably the "best" test for what I am seeking to achieve even if it's not the "best" test all-'round. Not to seem selfish, but there are those who would benefit from knowing what higher pressures or velocities would yield and I am not running terribly high pressures on anything so my experience may not be very useful to others in the long run. Actually, the whole point in having the .357 Max. is not to run it "at max.," but to better .357 Mag. ballistics somewhat (the barrel length does a lot of that work for me) and extend my range somewhat. The point behind the .223 is to not startle my rural neighbors (and I dislike noise myself) when I have a pest to deal with which is just out of reach of the effective range of my .22 LR.

[Jeff H]

WOW! What the chart shows is that in galvanic reactions with iron and aluminum is about ten time less than that of copper or brass.

WHAT A FIND, GREAT RESEARCH. tj

Hmmm, so, if there are aluminum deposits left in our bores after firing, maybe it's not as bad as aluminum gutter/trim with steel nails?

Oh, man, this is infectious.

Aluminum GCs sitting in brass cases for a long time,.....

Blazer ammo with aluminum cases/copper jackets,.....

The two seem to contradict, but the ammo-makers may know things we don't.



OK, I may be making a mountain out of a mole hill on the aluminum oxide thing, so I will leave this one alone. I will defer to post #2 before I drag everyone into another adventure. It's intriguing but I have burdened everyone enough with my original inquiry. Everyone's contributions are greatly appreciated. Hopefully, the ultimate result will be WHY it's OK to do what we're doing.


tjones, easy there, buddy. Remember what you said......


The only thing that would make such discussion better would be the setting; at the tailgates of a couple trucks at the back edge of a long lane while comparing targets and deciding which load to try next.

[Mooseman]

There ARE aluminum jacketed bullets. I dug quite a few of them out of a berm last year when I was cleaning a pistol range.

http://www.ncbi.nlm.nih.gov/pubmed/7114018

If you look at Winchester silvertip bullets you will notice the silvertip cover on the lead is at the front of the ogive and does not ride the bore when fired. Some bullets that resemble aluminum such as Aguila ICQ are actually a zinc alloy , which is neutral as far as abrasive oxidation or Galvanic action.

Another thing to consider.. ask any longtime gunsmith about 22 rifles that were cleaned with the cheap aluminum rods and how the end of the barrel and crowns are badly worn because nobody used a bore guide. It was combined Al-Oxide , and powder residue that caused the wear using those rods.

Like I said previously...test it yourself by sharpening your toughest steel knife on an aluminum rod used like a crockstick and then get back to me.

[Jeff H]

If you look at Winchester silvertip bullets you will notice the silvertip cover on the lead is at the front of the ogive and does not ride the bore when fired. Some bullets that resemble aluminum such as Aguila ICQ are actually a zinc alloy , which is neutral as far as abrasive oxidation or Galvanic action.

Yes, the rifle Silvertips are as you describe but the pistol bullets don't look like they adhere to that model.

I have a box of .257 Roberts Silvertips I have been holding onto for some time and the TIP is aluminum-colored but the rest of the jacket is like a "normal" jacket. Been meaning to chronograph those for something like 20, maybe 25 years now.

The Silvertipped pistol bullets do not look like that and I always assumed they were aluminum all the way to the base. I have never shot, let alone recovered one, so I don't know for sure.

You also mentioned something about a 2kfps threshold too. I have seen references to keeping things under that velocity with aluminum checks. I have no idea what the difference would be personally because I haven't run mine that fast. I suppose that Winchester might have been onto that if they really made the pistol bullets with a completely aluminum jacket and the rifle rounds only partially so.

Speculation on my part which neither supports or denies any other ideas stated so far.

[Mooseman]

The Silvertip® uses unique jacket materials custom tailored for specific calibers in the line to assure maximum performance. There are actually two different jacket materials used, one for the high velocity calibers, like 357 Magnum and one for the low velocity calibers like 38 Special. This enables Winchester to custom tailor performance for each caliber and ensure rapid energy deposit.
I believe they are Nickel / nickel alloy...Not Aluminum.
Rich

[Jeff H]

..........I believe they are Nickel / nickel alloy...Not Aluminum.
Rich

Hmmmm, no acquital through that avenue then.


I should have thought to look that up.

[fishhawk]

Well like I said before this will not be settled until some one some how can do a definitive test with measurements that can be duplicated that's the way I see it.

[Jeff H]

Well like I said before this will not be settled until some one some how can do a definitive test with measurements that can be duplicated that's the way I see it.

No argument there.

I was hoping someone knew of something that had already been done or that there was some other scientific evidence (either way)someone knew of.

In the meantime, I see nothing to disuade me from their use - just curious.


Thanks for entertaining my query, all.

[fcvan]

The plain based checks I make from soda can are made with the inside of the can facing out. There is a coating on the can to keep soda and beer from reacting with the fluid. Also, I have purposely made some checks and left them out to see if they oxidize. Under magnification I cannot discern any such oxidization. I also have seated and lubed some checks and let them sit for over 6 months. Under magnification, I still cannot detect any oxidization.

The checks I make from aluminum flashing also have not shown any oxidization. True, aluminum oxide makes great sandpaper abrasive. Untreated/coated aluminum will oxidize. The material I use is treated, is not oxidized, gets covered with boolit lube when seating, and has not shown any oxidization. Untreated aluminum will oxidize. Flashing material and soda can material is treated to prevent oxidization. Slapping some lube on them also treats the aluminum. I'm going to keep using aluminum checks because I make them and are pleased with their performance.

[Mooseman]

It takes a scanning Electron Microscope to see the Oxide...http://iris.lib.neu.edu/cgi/viewcont...ysics_fac_pubs

Your aluminum can material is coated with a micro layer of plastic/epoxy resin , but the oxide is still under that on the surface of the raw aluminum, and pressing out checks with a punch scrapes that surface coating...
http://digitalcommons.calpoly.edu/cg...&context=grcsp

[fcvan]

Mooseman, thanks for the links. I found them to be interesting reading. I'm not seeing the coating coming off of the soda can material, nor am I seeing appreciable wear in the check forming dies or in my sizing dies. I will certainly keep a look out for increased wear on these and on my barrels. Time will tell and I will keep the micrometer handy.

[Jeff H]

..........I still cannot detect any oxidization............have not shown any oxidization......., is not oxidized,...........and has not shown any oxidization. Untreated aluminum will oxidize...........treated to prevent oxidization............I'm going to keep using aluminum checks because I make them and are pleased with their performance.

Not the crusty stuff we can see and feel but the microscopic oxidation that forms almost immediately on freshly exposed (machined) aluminum and prevents or slows down the kind of oxidation/corrosion we can see and feel (the crusty stuff). Unless the material you are referencing is processed in a special atmosphere (possible), it would have the oxidation I am talking about even under the coatings you are talking about (also possible). This oxidation is not considered a nuisance typically, rather a benefit in most cases.

This is on our pots and pans utensils, etc. and forms a protective barrier - what Mooseman is referencing using a microscope to see. It's not terribly apparent that it is hard (or even there) because the substrate that supports it (the aluminum) is soft and gives way under the thin, thin layer in the form of dents.

I don't plan on not using mine either and do not intend to deter anyone else. My original curiosity was whether anyone knew of proof that it does no harm much more than it was about whether or not we should be using them.

I'm using them. I'm on board with others' opinions that it seems to be ok, but I also can appreciate Mooseman's points and will definitely keep them in the back of my mind.

[tjones]

The green growing crusty "brass oxide" is better ?

[Jeff H]

The green growing crusty "brass oxide" is better ?

No, of course not. I'm differentiating between the oxide we can't see and which is on most things aluminum as opposed to oxidation/corrosion that is very obvious to our senses - like "green growing crusty" stuff on brass, which we can see and feel. In other words, the oxidation I am talking about versus the "crusty stuff" would be like the bluing on a steel rifle versus plain ol' rust. Not a perfect example but similar in terms of one looking "ok" and the other very obviously not.

[Mooseman]

Oxides have different properties...and Brass / copper oxide is not considered to be an abrasive like aluminum oxide is.

[tjones]

But zinc oxide, and tin oxide is and iron oxide is. Sage (sagebrush7) claims he has run millions of aluminum checks through his tools. Maybe someone should ask him if he's worn them out dimensionally. tj

[Ajax]

Does any one have proof that using aluminum gas checks are damaging barrels?
I see a lot of speculation on both sides but nothing that proves they are causing damage or that they are not. I agree with fishawk, until a test is done we will not know.

Andy

[Sasquatch-1]

Here is an alternate way of checking this. If anyone here shoots a steady diet of Blazer aluminum case ammo through a semi auto it should cause the same effect shouldn't it? Measure the chamber and after about 6 months of a steady diet of these if there is an effect there should be some chamber wear.

As stated before this is from a very unscientific and unknowledgeable person.