Steel vs. Aluminum/alloy frame autos

I believe it is more of a "traditional than practical" issue. If you review the new offerings from gun makers (rifles especially) you will see more and more of the "plastic stock" than of the traditional wood because it is less expensive and there is a demand for it.
Personally, I believe that if John M. Browning were alive today he would use "modern" materials in his designs. If you look back at the improvements in the quality of materials that permitted the use of smokeless powder and high pressures you will see that it vastly improved not only the cartridges but more importantly the design of the firearms.
I also believe that 20 or 30 years down the road there will be the same discussion regarding the "new" wonder material (whatever it may be) versus the "traditional" plastic such as in the "old classic Glock".
Ask yourself this question, would you buy a 2007 model automobile that used 1920's technologies?

I have some of both, all steel framed auto's as well as some aluminum framed
auto's. Except for the SIG's, I like shooting the steel frame guns; but for
CCW purposes, I prefer the aluminum frame one's~!

About 20-odd years ago, a friend of mine inherited one of the earliest examples of the Para-Ordinance .45. I have no idea which variant he had (I think there was only one in those days), but I know it had an alloy frame. And judging from the condition of the thing, I also know it was a high-mileage specimen -- or a gun-abuse victim. The leading edges of the dust cover were out-of-true and the hole for the slide-stop pin was starting to look egg-shaped. Function was spotty, IIRC, and at the time I remember thinking I'd never own a aluminum-framed gun.

Well, that pistol was built probably in the early 1980s. Metalurgy and design have come a long way. Ever hear of a Taurus PT-92/99 having frame troubles? Mine hasn't, and it was built only a few years after that ill-fated Para. For that matter, has anyone heard of a Para of recent vintage going soft? I haven't.

I figure at the rate I burn rounds (especially spread across the stable,) a pistol that fails at 8000 rounds will still be in working order when they scatter my ashes. The all-steel 1911 and 4506 and Witness Elite Match will likely have more life left in them than the Taurus PT-99 or Ruger P90 or S&W 422, but its a tough call.

I guess my point is, these days, there's nothing wrong with alloy.

Steel Frame = Good

Polymer frame = Good

Aluminum Frame = Bad

Scandium Frame = ?

Steel and Polymer frames are very strong. Aluminum frames probably aren't a problem with 9mm or .45 caliber autos, as long as you don't shoot 10K+ rounds a year. There is a reason though why you won't see many aluminum framed .44 magnums. Aluminum alloys are lighter than steel, but also more brittle which tends to make them crack. Not likely a problem for the causal shooter, but a real concern to people who shoot that one gun a lot, especially in cold weather.

I'm not familiar with Scandium's material properties, but I can't imagine it being any less strong or more brittle than Aluminum.

There are too many variables here to give a set answer.Alloy aluminum...what alloy? cast or billet machined? heat treated? etc.

There are too many variables here to give a set answer.Alloy aluminum...what alloy? cast or billet machined? heat treated? etc.

Click to expand...

While I agree, an aluminum alloy frame with hardness comparable to steel will probably take a much greater loss to its toughness, making it more brittle. Assuming that it is properly designed, this may or may not matter.

Beretta uses an alloy called 7075 T6 in their frames. I'm not sure if that's one of the more common types or not, though.

Well, the US military uses aluminum alloy frame Berettas....

High-strength alloys, such as Fortel, 7075-T6, etc. have twice the strength of non-heat treated steels; however, aluminum has a lower surface hardness and lower wear resistance than steels and needs a protective coating. Protective coatings can wear off, exposing the raw aluminum, and that's where the wear begins.

As far as the Para-Ordinance frame with an egg-shaped hole, I am guessing that this was a casting, which is much softer than any heat-treated aluminum alloy. A 7075-T6 alloy frame will not experience this type of deformation.