[Daniel Watters]

It irks me when gunwriters use the word alloy as shorthand for aluminum. Most, if not all, metals used in the contruction of firearms are alloys. I can't think of any metal being used in its pure elemental form for the production of modern firearms. There certainly isn't an element in the periodic table called steel; it is an alloy of iron with other elements.

 

[Snake45]

"Alloy" doesn't bother me that much, but in the same vein, there are three that do: "tactical," "polymer," and "laminated." Whatever happened to the perfectly good words "combat," "plastic," and "plywood"?

One you don't see too much anymore (Thank The Lord!) is "combat conversion." Lessee, it was a combat handgun before you started dicking with it, and it's a combat handgun now, so what did you "convert" it into? :ehsmile:

 

[TommyGunn]

I'd like them to just state what the gun is made out of.
If it's "aluminum" say that.
If the frame is polymer, say that.
If it's silly putty ... say THAT. :shocked: Hey, I won't buy it ... but you can try.

As long as it's straight forward. "Alloy" isn't horrible but what IS the alloy composed of?
I am not a metallurgist ...and I didn't play one on TV.
I just want it simple & straight.

 

[spwenger]

How about "scandium"? Wikipeida defines scandium as:

a chemical element with symbol Sc and atomic number 21. A silvery-white metallic transition metal, it has historically been sometimes classified as a rare earth element, together with yttrium and the lanthanoids. In 1879, Lars Fredrik Nilson and his team, found a new element with spectral analysis, in the minerals euxenite and gadolinite from Scandinavia.

I'm sure that there is a heck of a lot more aluminum in the frame of a S&W "scandium" revolver than there is scandium.

 

[Charlie Petty]

would it be more agreeable to say "aluminum alloy"?

Of course you're right that pure metals are hardly ever used so if one simply said "aluminum" wouldn't that be equally wrong?

I reviewed one of the early "Sc" guns and the actual concentration of scandium is small, but the metallurgical benefit is significant.

 

[spwenger]

would it be more agreeable to say "aluminum alloy"?

That is the way I describe revolvers such as the S&W Airweights and the Colt Cobra or Agent, and bottom-feeders such as what is now called the Lightweight Commander and similarly framed pistol from S&W, SIG, etc.. I believe there was a time when those alloys were described as "aircraft aluminum."

Of course you're right that pure metals are hardly ever used so if one simply said "aluminum" wouldn't that be equally wrong?

I believe so.

I reviewed one of the early "Sc" guns and the actual concentration of scandium is small, but the metallurgical benefit is significant.

In light of the earlier use of aluminum alloys of (unknown to me) different composition, I prefer to describe the S&W "Scandium" guns as having a frame of aluminum-scandium alloy.

As to the "significance" of the scandium content, I have mentally been compiling reports of frame cracks in the flat area, below where the barrel screws into the frame, on J-frame revolvers with both versions of aluminum alloy (Airweight and Airlite). This was the latest:

Two were Scandiums (Airlites) and the other was a 642 (Airweight). They were all shooting regular .38SPL range ammo (PMC/S&B/Magtech). The shooter didn't notice any change in recoil or anything. The rest of the gun (cylinder, etc) were in good shape. The frame just fractured right between the barrel and where the crane fits into the frame, right where you said.

Source

Steel by the way, is primarily an alloy of iron with carbon, with other elements optionally added in small quantities, to confer specific properties. I would suggest that any discussion of steel alloys would best be split into a separate thread.

 

[Daniel Watters]

Aluminum alloy would be the the most descriptive. Using the word aluminum alone would be almost as descriptive, if not technically precise. My point is that use of the word alloy alone really isn't descriptive of the metal being used; nor is the term lightweight alloy. The latter could describe an aluminum alloy, a titanium alloy, or a zinc alloy.

Isn't some of the frame cracking in the Airweights and Airlites attributable to simply over-torquing the barrel during installation? For that matter, is S&W is still using the crush fit method, where the frame threads and barrel threads are close in pitch, but not the same?

 

[spwenger]

Isn't some of the frame cracking in the Airweights and Airlites attributable to simply over-torquing the barrel during installation? For that matter, is S&W is still using the crush fit method, where the frame threads and barrel threads are close in pitch, but not the same?

I don't know but it seems (a) quite plausible when it is observed with standard-pressure rounds, even with the added strength of the scandium alloy and (b) certainly a matter that would warrant the attention of Smith & Wesson.

Does crush fit involve a difference in pitch or a slight positive interference, where the male thread (on the barrel) is about 0.001" larger in diameter than the female thread (in the frame)?

 

[Charlie Petty]

The newer "J" frames such as the SC models use the two piece arrangement where a barrel section- they call it a barrelette- is covered by an alloy shroud and then torqued into the frame with a "wrench" that engages the rifling. There is a tab on the shroud that engages a slot in the frame to keep everything lined up.

It is done on a machine set to a specific torque load. I am not aware of any disparity in threads.

 

[spwenger]

The newer "J" frames such as the SC models use the two piece arrangement where a barrel section- they call it a barrelette- is covered by an alloy shroud and then torqued into the frame with a "wrench" that engages the rifling. There is a tab on the shroud that engages a slot in the frame to keep everything lined up.

It is done on a machine set to a specific torque load. I am not aware of any disparity in threads.

Does this mean that the tab on the shroud has replaced both the old pin and the "crush fit"?

I have never handled one but I once saw an episode of How It's Made that covered the X-frame S&W revolvers. As I understand it, those guns use what is basically the old Dan Wesson barrel-and-shroud system except that the customer is not furnished a spanner to remove and replace the barrel. I got the sense that the nut on the end of the barrel is torqued too tight to be removed by the user.

 

[HankB]

. . . One you don't see too much anymore (Thank The Lord!) is "combat conversion." Lessee, it was a combat handgun before you started dicking with it, and it's a combat handgun now, so what did you "convert" it into? . . .

Actually, a lot of "combat handguns" weren't actually suitable for combat, as they weren't reliable - companies like Colt's lost their way and were putting out a lot of jammamatics. Hence, the need for "reliability" packages, and with the rise of IPSC-type shooting ("combat shooting") in the '70s, the poor triggers and itty bitty sights that the military accepted (handguns were never more than a footnote to the military in the early 20th century) were found wanting in games where the pistol was primary. So better sights & triggers - along with improved reliability and accuracy - became necessary for pistol "combat" games. Hence "combat conversions."

Plenty of pistols are made today that are good to go out of the box, so the "combat conversion" of yesteryear is being done as SOP by the factory . . . it's not a "conversion" any more. So a term that once had meaning has been rendered obsolete by technology and the marketplace.

There are other instances where what was once noteworthy has become standard - for example, are any manufacturers making guns today that are advertised as "nitro proofed" or "suitable for smokeless?"

As for terms like "tactical" . . . all too often it means "overpriced and underperforming." My theory is that the more impressive the name, the less impressive the performance. So for example if I ever see ammo labeled "Tactical Fire Ninja Extreme Dragontooth Killshot" there's a fair chance it won't work at all, and may even be more of a hazard to the user than the target.

 

[Retmsgt.]

We were working on a bunch of easy to understand definitions of these terms awhile back on one of the 1911 Forums, to wit;
Kimber Mfg.Inc. Alloy-frame- Quaint marketing terminology for Anodized Aluminum which will bulge out in the ramp at 2000 rounds requiring owner to either cut a Para/Clark Ramp-barrel in or hog out frame for a EGW ramp insert.

MIM parts. Marketing phrase- As good as forged, will last a lifetime- really means will lose tension, wear out or shatter within 1000 rounds.

Match-fitted parts/slide/frame- Means 98% close, will take 500 rounds of Ball and a lot of creative language to wear in and become 98% reliable.

Tactical- Term used to lure LEOs and wannabe's into buying as in; You aren't Tactical unless you have this. Arms Marketers are wise to the average LEOs' psyche.

Law Enforcement Only; See Tactical, no better than what's offered to civilians but...

Lightweight Speed-trigger- Expect full-auto operation.

Bulletproof- Metal too hard to fit.

Drop-in fit- Hope you have files/stones/mallet.

 

[Kevin Gibson]

Doesn't bother me in the least bit. If someone wants to use incorrect terms it really doesn't bother me as long as I know what the guy is talking about. When using anything but the absolute correct terms, one has to be careful and selective. You have to make sure the incorrect term doesn't lead one astray. As long as nothing unsafe is being done, or such descriptions don't make someone think you're talking about one thing when you're talking about somehting else; I really don't care.

But I'll tell you, I really think these things keep Kokalis up at night...that guy's a bit on the Anal Retentive side and anything but 100% nomenclature correct really pisses that guy off. Sorry, I just dont take life, or myself that seriously.

 

[Skeptic49]

Some folks follow the manufacturers nomenclature, some put in definitions and some well...just go on and on.

"Don't call a spade a spade, call it a <ed> shovel and you'll have a best seller.

Geoff
Who remembers the glory days of Guns&Ammo, where they converted .38 into millimeters, instead of .357...sigh.

 

[Charlie Petty]

Does this mean that the tab on the shroud has replaced both the old pin and the "crush fit"?

not really. The pin was gone long before and the tab just serves to keep the shroud from turning.

It is similar to the Dan Wesson system in principle, but does not use a separate barrel nut

 

[spwenger]

Does this mean that the tab on the shroud has replaced both the old pin and the "crush fit"?

not really. The pin was gone long before and the tab just serves to keep the shroud from turning.

It is similar to the Dan Wesson system in principle, but does not use a separate barrel nut

So what keeps the barrel from shooting loose?

My understanding, so far, is that the barrel proper is of steel, with a shroud of a lighter metal and that the shroud has a tab to keep it from rotating. There is no nut on the muzzle end to tension the barrel as on a Dan Wesson or an X-frame S&W. This suggests that the barrel (or barrelette) still requires an interference or crush fit not to shoot loose from the frame.

I'm not arguing, I'm just not clear on the concept described yet.

 

[Daniel Watters]

The barrel insert has a flange at the muzzle so the shroud won't fall off. One could argue that if enough torque was applied when the barrel was screwed in, the barrel could be considered under tension.

 

[spwenger]

The barrel insert has a flange at the muzzle so the shroud won't fall off. One could argue that if enough torque was applied when the barrel was screwed in, the barrel could be considered under tension.

Okay, that answers part of the question but does not clarify whether there is still an interference fit of the threads.

I can see how a flange could create a specified amount of tension, along with some friction, much like that on a strain screw that is screwed firmly into the frame, but the latter is still capable of being shot loose if not LocTited in place.

 

[Charlie Petty]

capable of being shot loose if not LocTited in place.

not so

The rifling twist is opposite the thread direction so it should be self tightening.

 

[spwenger]

capable of being shot loose if not LocTited in place.

not so

The rifling twist is opposite the thread direction so it should be self tightening.

I am not competent to judge whether that is true but reversing the thread direction on the sleeve of the ejector rod on S&W revolvers did not solve that problem. Admittedly, the mechanics are different there but I have seen strain screws, side-plate screws and sight-mounting screws shoot loose, presumably from vibration.

I am intrigued, with the amount of knowledge here, that I can't get an answer to what I thought was a simple question: Is there still an interference fit on the threads of the barrel and frame of the Airlite revolvers?

If only the Airlite guns use the two-part barrel, I have to assume that the interference fit is still used on the Airweight guns.