Aluminum Guns

[BlueTrain]

Skeeter Skelton did a test of both a Colt Gold Cup and a Commander, now called a Lightweight Commander, many years ago. The reason for testing the Gold Cup was because of the widely held belief that they weren't as durable as a regular Government Model but they were. At least that one was. The Commander was tested I guess just because they were doing the other.

They did manage to crack the frame but it took a lot of rounds and even so, it was only a hairline crack. This test was probably 30 years ago.

Some aluminum framed guns did have a deserved reputation of being a little fragile, notably the Stars. They never became unsafe but would start to loosen up. But the same thing can happen to a revolver.

 

[Chris_B]

My SiG Sauer P226 is AL framed, made in '88. Looks and operates as new

Isn't the 92fs also AL frame?

I admit, I like all steel but the AL doesn't bug me

 

[orionengnr]

But with the anodized finish, you can't just polish out the marks and shine it up like you can with a steel frame.

True Dat. I bought a Kimber that "someone" had polished the aluminum feed ramp. It got chewed up in no time flat by just the leading edge of the nickel cases. JHP ammo was a no-go. The fix:
http://forums.1911forum.com/showthread.php?t=146569&highlight=ramp+insert

Tapping holes in aluminum is trouble waiting to happen unless you put threaded inserts in.

While I have seen exactly one picture of a 1911 with a crack from the slide pin stop to the frame rail (directly above) I would not agree that it is "trouble waiting to happen". I can list numerous motorcycle/automotive applications using tapped holes in aluminum.

Then you have the problem of electrolysis between steel and aluminum.

As far as this goes, dissimilar metal (galvanic) corrosion is only a factor when the two metals are in direct contact (no lubrication) in the presence of moisture for a period of time. If your gun is cleaned/lubed at least occasionally, galvanic corrosion will not be a factor. Can anyone show us an example to the contrary?

Lubrication of surface to surface contact is also a problem.

How is lubrication of surface to surface contact "a problem"? Any reasonable lube will provide all the protection necessary.

Most of my 1911s are alloy framed. Aside from the aforementioned "hand-sanded" feed ramp, I have had none of the "issues" quoted above.

 

[44 AMP]

Back in the 1970s Shooting Times (IIRC) did a "11,000 rnd torture test" on two aluminium frame guns. One was a P-38 and the other a S&W, a model 59, I think, but it could have been a model 39, I don't recall exactly any more.

5,500 rnds per gun, shot in about two days or so, with no serious cleaning and occassional shots of lube to keep them running. Both guns had been carefully inspected before beginning, and after.

Basically, the only thing worn was the finish on the fames where the slides rubbed.

The big advantage of Al over steel is lighter weight while keeping enough strength to do the job. Auto pistol frames are not the most highly stressed part of the pistol. The drawback is that Al work hardens faster than steel, especially under torsion (flex) stress. Both metals can be equally "hard" on the surface, but handle stresses differently.

How many rounds should a gun last? Not how many years, but how many firing cycles are expected before something breaks down? Millions of guns from yesteryear are still around in good shape, but how many of them got shot 10,000+ times?

I'm not a cop, nor a serious competitor. I have many guns that I have owned for 30yrs that don't have more than a couple thousand rounds put throough them. Some others I have are in the 3-5k range. Maybe a couple over 10k, and those are .22s!

You can wear out anything through normal use. I don't know how long (rnd count) a pistol should last, all I know is I have not worn one out yet.

If a frame, of any metal, cracks before you have replaced a barrel due to wear, then I think that frame has failed early. Thinking of how often we hear about those failures, vs the number of guns running, it seems pretty rare.

 

[Skans]

If a frame, of any metal, cracks before you have replaced a barrel due to wear,

Hers's the problem - it's not just about aluminum frames cracking. Other problems with Aluminum:

1. worn out feed ramps
2. worn frame rails
3. easy to scratch
4. surface is much more prone to holster wear, scratching, dings, etc, and you can't just buff or polish it out.
5. if an internal steel part breaks it very likely will chew up part of your aluminum frame - this happened in a PT-99 of mine.
6. corrosion - aluminum is not as corrosion resistant as SS. Where you really see this is in older aluminum guns where the surface treatement/paint etc. has deteriorated.

I do not understand why gun makers are still using aluminum in anything but dirt-cheap guns. I also don't understand why consumers let gun makers get away with using aluminum in guns. If it was Zamac (has aluminum as a componant of this alloy) instead of aluminum everyone would be poo-pooing on it as being cheap pot metal. But, because manufactures call it "aircraft" aluminum - well, it's got to be some goooooood stuff, right? That's why the FAA has strict regulations for checking airplanes for cracks and corrosion....because aircraft aluminum is such "good stuff".

If weight is a huge concern, which it shouldn't be in small handguns, then use polymer or maybe titanium. It doesn't have the look and feel of metal, but good polymer guns are far more durable than aluminum. Otherwise stick with stainless steel or carbon steel with surface treatment.

The real reason why gun makers use aluminum is because it is cheap. It's cheap to mill a billet of aluminum ... why???? Because it's soft.

 

[BlueTrain]

No, they use it because it makes a lighter gun and people like me buy it for that very reason. It also won't rust. It doesn't seem to be cheap at all. And you can't make everything from plastic because, well, just read a few of the threads here. Besides, you wouldn't buy a plastic Colt anyway. And weight is still a consideration sometimes. Otherwise we'd all be using pistols that weight more than 50 ounces.

I've never had any gun with a broken internal part; I've never seen a handgun with an aluminum frame that was in the least corroded; and I've never seen an aluminum framed gun that was any more worn than a steel framed gun.

Steel frames wear and crack, too, even the ones that everyone thinks are the greatest thing since the BAR.

 

[MrAcheson]

I do not understand why gun makers are still using aluminum in anything but dirt-cheap guns. I also don't understand why consumers let gun makers get away with using aluminum in guns. If it was Zamac (has aluminum as a componant of this alloy) instead of aluminum everyone would be poo-pooing on it as being cheap pot metal. But, because manufactures call it "aircraft" aluminum - well, it's got to be some goooooood stuff, right? That's why the FAA has strict regulations for checking airplanes for cracks and corrosion....because aircraft aluminum is such "good stuff".

Zamak is a zinc alloy with some aluminum in it. Aircraft aluminum is the other way around, aluminum with a little zinc. Zamak 3 is more than 95% zinc with about 4% aluminum and less than 1% copper and other trace elements. 7075 aircraft aluminum is at least 90% Al with less than 6% zinc, 3% magnesium, and 2% copper. The fact that you think they are the same or even comparable means you have no understanding of metallurgy or materials.

 

[Nnobby45]

Quote:
I’ve had a couple of cops bring me their duty pistols for work and I’ve been astonished at what I’ve found. When I cocked the hammer of one of them, I found three pieces off bitten of finger nail and a corner of plastic from a plastic ketchup packet….I mean *** MAN! Clean your freaking gun.

And that's not counting the doughnut crumbs.

 

[Nnobby45]

That's why the FAA has strict regulations for checking airplanes for cracks and corrosion....because aircraft aluminum is such "good stuff".

Well, if your pistol sees as much hard use as an airplane that has it's wings fall off from stress, then your pistol ha lasted a long, long time. It'll probably last a lot longer, since pistol use doesn't flex the alulminum up and down at various joints.

Alulminulm is a technological advancement. Good grief, they're making more all the time---not less.

I had an all steel P220ST Carry. Great gun to shoot, but I'd never carry a gun that heavy.

 

[natman]

People make guns out of aluminum because it's LIGHTER than steel.

If you shoot thousands of rounds per year practicing for competition, then you might see an advantage in a steel frame. If you CARRY it the weight difference will be an advantage to aluminum.

 

[BigJimP]

The only alloy frame 1911 I have is a Kimber Tactical Pro II, 4" ...and it has at least 3,000 rds thru it with no issues.

I do find it scratches a little easier than a steel frame / but not significantly easier ....and that's more a function of the coating than the frame material in my opinion.

The only reason to buy an alloy frame 1911, in my mind, is to reduce weight. Overall I prefer an all stainless gun / but they are heavier...

 

[madmag]

The only reason to buy an alloy frame 1911, in my mind, is to reduce weight.

That's it. Sometimes we make it complicated, but it's just about the weight. I like my steel 1911, but after all day carry I tend to walk with a tilt.

 

[Chris_B]

Hers's the problem - it's not just about aluminum frames cracking. Other problems with Aluminum:

1. worn out feed ramps
2. worn frame rails
3. easy to scratch
4. surface is much more prone to holster wear, scratching, dings, etc, and you can't just buff or polish it out.
5. if an internal steel part breaks it very likely will chew up part of your aluminum frame - this happened in a PT-99 of mine.
6. corrosion - aluminum is not as corrosion resistant as SS. Where you really see this is in older aluminum guns where the surface treatement/paint etc. has deteriorated.

I do not understand why gun makers are still using aluminum in anything but dirt-cheap guns. I also don't understand why consumers let gun makers get away with using aluminum in guns. If it was Zamac (has aluminum as a componant of this alloy) instead of aluminum everyone would be poo-pooing on it as being cheap pot metal. But, because manufactures call it "aircraft" aluminum - well, it's got to be some goooooood stuff, right? That's why the FAA has strict regulations for checking airplanes for cracks and corrosion....because aircraft aluminum is such "good stuff".

If weight is a huge concern, which it shouldn't be in small handguns, then use polymer or maybe titanium. It doesn't have the look and feel of metal, but good polymer guns are far more durable than aluminum. Otherwise stick with stainless steel or carbon steel with surface treatment.

The real reason why gun makers use aluminum is because it is cheap. It's cheap to mill a billet of aluminum ... why???? Because it's soft.

As I said before, I prefer steel.

I only have experience with one AL framed pistol- my 1988 P226, in 9mm

The aluminum is not just raw aluminum. It is hard coat anodized. Mine had a weird circular rub mark in the hardcoat, at the takedown lever. A previous owner tried to...I don't know what they tried to do. Looks like they didn't know how to take the lever out but tried anyway

I made a slurry of kitchen softscrub and gunoil. 1:4 ratio. I rubbed the wear mark gently with a cloth and some of the slurry. The wear mark is all but gone

I agree that even hard coat AL is more prone to wear and scuffing, and obviously if steel gets a scratch it's not had it's 'armor' pierced

My 22 year old P226 has had lots of rounds through it, judging by the wear on the outside of the barrel. No 'dip' in the barrel though. The slide has minor wear at the front, looks like it saw a little holster duty. Inside of the (steel) slide has wear, you can see the matching wear on the side of the barrel at the '9mm para' rollmark. There are a few- very few- small chips out of the ano on the frame rails. And that's it. The milky spots in the photo below are from the lube I use, it's not wear. The chips are so small you can't see them in a photo taken that far away.

The barrel s/n matches the frame, and the barrel tells the story on rounds fired. This was no safe queen

While again, I prefer steel firearms, I have to say that my Sig is a fantastic pistol and has very little wear for any 22 year old pistol that has seen the level of use it has- steel or AL frame. can't say enough great things about that P226. I see no problems with that pistol having an AL frame. I'd prefer steel; I like the look of blue better, it's a nice feel-good knowing the frame is steel and the mass would soak up more recoil, not that the P226 in 9mm has a ton of it. I would not hesitate to buy an AL framed pistol if it was made as well as my P226- but if the identical pistol sold for the same price with a steel frame, I'd buy the steel pistol. That's just my preference

 

[Sulaco2]

Alum frame guns and throating

You guys are making me nervous here. I have a 1950's Colt LW Commander in .45 and recently noticed that someone in the past has "polished" the feed ramp A LOT, well past the hardning done at the factory. It still feeds ok but I notice some brands of ammo will scuff up the ramp or what’s left of it, mouth of the casing going by on the ramp into the unramped barrel I think.
I think this (throat job) was done to allow feeding of HP's as they will not feed very well in pistols of that era. Anything I should do with this gun? Outside of replacing the standard safety grip with an extended one to stop it bruising my hands its stock. I have read about installing a steel feed ramp, pin or "bump" smiths working to revive older throated alum guns....

 

[Skans]

People make guns out of aluminum because it's LIGHTER than steel.

I understand that this makes a difference in full-size pistols. But, with a gun like the Rohrbaugh R9, the frame size is so small, that the difference in weight between drop-forged steel and aluminum is minimal. And, in a 9mm gun that is that small and is apparently having problems based on CS statements like "expect it to break if you use it for a range gun" - maybe drop-forged steel is a better choice than aluminum.

My concern rests more with the smaller "pocket-sized", full-power autos. I think manufacturers are cutting corners by using aluminum.

Also, when I go into a gunstore and look at used autos, why is it that I can tell that a particular gun has an aluminum frame from 5 feet away???? It's because the Aluminum frame guns that have been carried are all missing finish, dinged and scratched up. They tend to look like something that got stuck in a garbage disposal. A small S&W DAO aluminum frame auto sticks out in my mind as a recent encounter.

But, hey, I know that some guys just love their beer, and I completely understand this.........I just never understood how that spills over to their beer cans.

 

[jmr40]

The very 1st 1911 I ever owned developed a cracked frame shortly after I bought it. In all fairness it was a used gun, put together from a mix of GI parts and after market parts. I was young and dumb and was taken advantage of by someone. But I had to have a 1911.

I have read, but cannot verify, that a gun with an aluminum frame is good for around 30,000-35,000 rounds before wearing out. I know that there are steel framed pistols with over 100,000 rounds through them and going strong. There are plastic framed Glocks with well over 250,000 rounds through them and still functioning.

I believe the aluminum framed guns are the least likely to hold up to severe long term use, but it would not stop me from buying one if I wanted it. I have guns with all 3 types and doubt I will ever wear out any of them.

 

[yrralguthrie]

recurring themes

Since this is my thread, I will comment on some recurring themes.

First "They use aluminum because it is soft and easy to machine. " That's just not true. I can say first hand that machining aluminum mostly 6061 that it is no easier than machining mild steel. Aluminum tends to gum up the bits and I call it stringy. Mild steel cuts easily and cleanly and the mess is easier to clean up. Stainless steel is far harder to mill than mild steel. Even in a CNC machine more special precautions will have to be taken for stainless and aluminum than mild steel.

This theme is repeated just through lack of knowledge, just because it's soft. Some plastics take more care to machine than steel. That's one reason they are usually molded.

Second using the old timers opinions of aluminum. While they had a lot of experience in the traditional area of guns, all of them I've read had a built in prejudice against anything new. Even if they did a comparison it was skewed.

I asked for first hand experiences. One good reason is the picture of the cracked aluminum that was mentioned. Who knows what was actually done to that gun before it cracked? Could have been dropped on a concrete floor and then fired. The picture poster's not going to own up to being at fault, naturally it's the aluminum.

I do think that the finish on aluminum frame guns is not as durable as most of the steel finishes. But that wasn't the question. But a valid point in another thread.

Some have stated that there isn't enough difference in weight between a steel gun and an aluminum gun. I believe a 3in aluminum carry pistol weights about 20 oz vs. a steel 3in carry about 30oz. That is significant. 50 percent more, or 33 percent less depending on how it's compared.

Stainless steel is durable and doesn't show scratches, blued steel is very good looking, aluminum is light. And all will last long enough for me to list them in my will.

Thanks for the input

 

[yrralguthrie]

Say What???

I do not understand why gun makers are still using aluminum in anything but dirt-cheap guns. I also don't understand why consumers let gun makers get away with using aluminum in guns. If it was Zamac (has aluminum as a componant of this alloy) instead of aluminum everyone would be poo-pooing on it as being cheap pot metal. But, because manufactures call it "aircraft" aluminum - well, it's got to be some goooooood stuff, right? That's why the FAA has strict regulations for checking airplanes for cracks and corrosion....because aircraft aluminum is such "good stuff".

MrAtcheson:

Zamac is not used why are you comparing it?? It's not aluminum. Bullets have zinc in them, but bullets are lead.

Manufacturers don't call anything aircraft aluminum. There is no such thing as aircraft aluminum. The uninformed use that term.

FAA has strict regulations for checking airplanes. The only airplanes that use steel anymore are homebuilt and then use chrome moly steel, which has to be checked much more often than aluminum, because it rusts. Airplanes were originally built of aluminum because it was lighter. Today chrome moly steel is lighter and stronger per pound than aluminum. Airplanes still don't use steel, even chrome moly, because it doesn't last as long. It rusts and will fatigue and break quicker than aluminum. Don't believe me? Check out an aluminum frame bicycle and a chrome moly framed bicycle that have been hard used and left in the weather. Only one will be rusted.

In a gun, I'm not sure the fatigue issue is an issue. The fatigue is generally caused by repeated bending moments. I don't believe there is much bending in a gun.

 

[madmag]

Aluminum tends to gum up the bits and I call it stringy. Mild steel cuts easily and cleanly and the mess is easier to clean up.

I can tell you from first hand machining experience, that's only true for low grade aluminum like they use for toys. 6061 or better machines very smooth and easier than mild steel, and will not gum up the cutting bit. In fact, you can even tap 7075 without a steel insert with good results. Try that with low grade aluminum and you do indeed have a gummy mess.

Stainless steel is far harder to mill than mild steel.

Also incorrect. 416 stainless machines about as easy as mild steel and a lot easier than tool steel grade. Now 440 stainless or 300 series stainless is a bear to machine.

Even in a CNC machine more special precautions will have to be taken for stainless and aluminum than mild steel.

Again not correct. I spent years programming and running CNC milling machines. Aluminum is not special to cut. You use higher tool speeds and feeds, so it goes faster. Other than that, no big deal. Except for the fact most machinist like machining aluminum over any type of steel, it's just easier.

BTW, one exception is that on a surface grinder aluminum will clog the grinding wheel, so you have to add lubrication like wax or other to kept the wheel clean.

 

[pythagorean]

The Colt LW Commander is a fine Aluminum framed .45 ACP that I have never had any trouble with. The Beretta M-9 9mm is another. I have a Colt Cobra that numbers with these in strength but mine is a .32 New Police which is a relatively mild cartridge in the first place.

Remember that the AR 15 is aluminum framed and works quite well!

The argument against aluminum is durability but if the aluminum receiver is not under stress in the first place to do what has to be done then the question is why use steel.

In the 1911 the rumor or accepted notion is half the life of a steel frame. But how this is tested and which brand or make is used is the question. The Beretta M9 works fine for the Army and that should say something.