Pistol Smith Forum banner
1 - 20 of 27 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
We've had a heated discussion lately about which is better...cast or barstock frames...or if there is really any difference at all. What do you forum members have to say on the subject? Anyone have any FACTS about it rather than merely opinions?

Are barstock frames demonstratably stronger? Or just better for aesthetics? Do cast frames have a greater chance of cracking due to possible imperfections in the casting?

Please enlighten us.
 

·
Registered
Joined
·
403 Posts
Lets just look at it from a purely engineering standpoint.

The very best racing crankshafts are machined from billets, not castings or forgings. Why? Because of superior grain structure mainly and the lessened risk of internal flaws. A billet requires so much material to be removed, most any surface flaws are guaranteed to be eliminated.Forgings, as good as they are, always have the risk of subsurface flaws. Slight risk but its there. A casting just doesn't have the grain structure to be useful in thi application, due to the possibility of flaws and a less than optimal grain structure.

The difference is application specific. For a truck engine, a forged crank is prefered, and for a car many cranks are cast.

Same goes for gun frames.

A investment cast frame is probably structurally fine for a frame. There is a minor risk of casting shift and internal flaws. Quality control can take care of that if it is propperly done.

A bar stock frame, would be a frame machined from a solid chunk of steel. This would be similar to the billet crankshaft. The probability of flaws is reduced, but manufacturing costs are much higher.

A forged frame could be expected to have a better grain structure than a cast one, and a lesser chance of internal flaws due to to the hammering process involved at temperature.

Now the BIG question is, which do you use? Is the cast frame suitably strong enough for a frame? Most assuredly so. If the QC and machining are done propperly I see no reason for the need of a bar stock or forged frame.

If your going to go hotter than design bullets in the gun, or shoot IPSC forever with the gun, you might want a forged frame. With better grain structure you would expect that it is somewhat stronger. It would perform better in an abusive situation like competitive shooting, i.e. extended life.

I see no reason to use a bar stock frame in a 1911 pattern gun. It's just overkill. It might make you feel better to have one, if anyone even makes them, but it's just not necessary.

So,

Cast frames are good enough for almost any application.

Forged frames are plenty strong for any application.

Bar stock frames are just overkill and unnecessary.

Thats the basics, there are plenty of specifics I have left out, but the above is good engineering. Any arguments to it are just varying opinions of the validity of the thinking.

_________________
if it flies it dies, if it runs it's done

<font size=-1>[ This Message was edited by: Peter Zahn on 2001-07-06 00:02 ]</font>
 

·
Registered
Joined
·
3,831 Posts
Interesting enough Caspian claims that they have an almost ZERO return rate on their cast recievers and guarantee them for LIFE.

The same guys Vickers sees shooting a million rounds a year, shoot Caspian cast recievers for the most part.
 

·
Registered
Joined
·
26 Posts
I think the metallurgical side was skipped over in discussing the various processes. The quality of the billet, bar or forging, can only be as good as the quality of the material that you start with. Start with "dirty" steel and you probably have a product that is going to fail, regardless of what process is used. I would also disagree that starting with a billet and machining away a lot of steel is the best way to make sure you have "good" steel. A billet has only a minimum amount of forging reduction and the deeper you go the more likely you are to find defects. A well designed closed die forging, producted from the correct steel is going to be stronger than any product produced from a billet, barstock or a casting.
The only purpose of a casting is to reduce manufacturing cost, not to improve the product. This does not mean that castings cannot be used for many purposes, but if we are talking about strength, then a forging will win everytime, assuming the material and heat treating processes are the same.
 

·
Registered
Joined
·
403 Posts
Houston,

maybe I wasn't too clear in my definition of a billet, sorry about that. I was trying to keep it simple. My idea of a billet is a forged billet, no special shape, just a square hammered on down to a different size, we just always called them billets or billet forgings. Maybe they call it something different now, i don't know. We got the same grain structure as a precision forging, and in our experiences, less flaw potential. This was on rather large pieces also, steel mill and power generation parts to be exact. Our standard Qc involved mag-particle, ultrasonics, and x-rays. All I can comment on is what we found to be the case at the time.


Dane,

I dont doubt that cast recievers go a million rounds or more. The frame doesnt really have a tremendous amount of stress on it, at least not that i can tell. I would be more than happy with a cast frame and never worry about it, something else is sure to break or wear out before the frame.

I was just making comments based on my past experience in designing and building large machinery. Our preferences were cast when possible, forged when necessary, and billets when only absolutely necessary.

Gyp_c2,

I can probably argue the cast or forged slide either way. It wouldn't make any difference to me which was used in my gun really, just like the frame. If the parts are well made they should last as long as you need. Ok,Ok, all things being equal, sure go for the forged parts, but the cast ones will work as well in this application.

I think people get way too wrapped up in these matters. Most will never ever shoot enough to notice any kind of difference between the choices.

It aint near as important as how the parts are all put together.
 

·
Registered
Joined
·
1,420 Posts
...Just a question Peter! I couldn't care less...As long as it's not defective and is close to spec, I'm tickled to death!...or is that pickled?

You know what I mean...
Thanks for the reply!!!
How's that carry thing runnin'? The scorpion thingee'..."Stinger" that's it!

How's it runnin?

Thanks again...
 

·
Registered
Joined
·
3,831 Posts
Count me as a big fan of forged :grin: I just wanted to give some perspective on what a cast frame is capable of these days.

There are forged, bar stock and cast frames on the market. Doesn't the heat treat of all three count more for the durability or lack of than material?

One major maker of production guns claims "forged frames". When I cut them on the mill it's like butter. While another maker's forged frame actually shows the difference while cutting.

What is up with that?

<font size=-1>[ This Message was edited by: Dane Burns on 2001-07-06 14:03 ]</font>
 

·
Registered
Joined
·
126 Posts
Here is the MD Labs take on the issue:

To say that the 1911 frame is not a load bearing component is fallacious. Note the tendency of the rails to wear due to loads under fire. Impact from the slide during cycling is also considered loading. Very forceful loading.

The tendency of pin holes to elongate or otherwise change shape is caused by loading.
Basically, any part that is subjected to sliding forces, impact, rotation, pressure or other forces must be considered a load bearing part from an engineering aspect.

Certainly, some see less load than others, but nearly all of the components in a 1911 are, in one way or another, subjected to greater or lesser loads during cycling of the weapon.

A properly manufactured forged steel frame or slide will be far stronger and outlast a barstock piece, and they are especially better than a cast piece. Cosmetically, they take a polish much better than castings and in some cases better than barstock.

One of the reasons you may not see a lot of forged crankshafts these days is the complexity and expense of the part. Manufacturers that are trying to cut costs will often use near net shape castings rather than forgings due to reduced tooling and finishing costs.
One look at the best pistons, connecting rods and crankshafts used in F1 race cars, GP motorcyles, the high end German cars like BMW, Mercedes and Porsche and you will see that they utilize forged crankshafts. One reason: STRENGTH!

A properly forged component will be stronger and have better grain structure than one made from bar stock. Roll forged bar stock is generally superior to castings, especially when the roll forging direction of the grain is selected so that it complements the structural necessities of the part.

Basically, castings do not have much in the way of desirable grain structure. Their grain direction is by and large amorphous.
Forging modifies the grain structure of the steel to conform and flow through areas like the trigger guard and frontstrap. This allows greater directional strength and structural integrity.

A cast slide is a nightmare waiting to happen. Castings, especially those with sufficient carbon content to be hardenable, tend to precipitate the carbides in fernlike dendrites, rather than allowing even distribution of the carbides throughout the structure.

This causes built in weaknesses. Imagine the dendrites as the perforations in paper, in the nature of fracture lines waiting to occur after stresses have been exerted on those areas. Obviously, this is less than desirable in a combat weapon.

There are also problems with cast slide rails holding tolerance, the breechfaces peening, and the locking lugs stripping out.

I don't think Dane was implying that cast recievers are lasting 1,000,000 rounds.
I would sure like to see ANY receiver that went 1,000,000 rounds without failure.

At MD Labs we build HARD USE guns. Our priorities are reliability and durability, we do not cut corners on the guns we build.

In the grand scheme of things, the cost of a forged frame and slide is not significantly higher than barstock or castings.

Cast frames and slides should to be avoided.
Properly treated, barstock is excellent.
Forged frames and slides are the best for durable hard use guns.
 

·
Registered
Joined
·
26 Posts
Peter - Glad you did not take my comments as an attack because I certainly did not intend it that way. I understand your point regarding billets as actually "forged billets" which do have sufficent reduction to qualify them as true forgings.
As far as the comment on heat treating - As important as using "clean" steel, heat treating is even more important. That's why I ended by saying "a well designed, properly heat treated" forging is going to win every time.
I have had only one pistol with a cast stainless frame and it developed a crack. At my option I replaced it with a alloy steel frame that was forged. I prefer forged alloy steel over cast stainless steel when it comes to pistols.
 

·
Registered
Joined
·
3,831 Posts
Steve, a good attorney doesn't ask questions he doesn't already know the answer to.

Like I said my vote is forged.

The millions of rounds that go down range every year at Fort Bragg as shot through at least several pistols....most of them built on Caspian cast frames.

When we get to what guns are used for and the guns actually putting them through "hard use" my vote will go with the experience of those that have actually done it and still do it on a daily basis.

DELTAs guns are cast Caspian frames for the most part by my info. They do shoot a million or so rounds a year. If there was a problem in durability they would have seen it I suspect.

I prefer forged frames because they are easier to get a good metal prep on and final finish is better cosmetically IMO. How much difference forgings makes in the longevity of a 1911 over a quality cast frame like Caspians? I doubt there is any. If there were the guys who define " hard use" would have found it I suspect.
 

·
Registered
Joined
·
403 Posts
Steve,

I hope you were not implying that i said a frame isn't a load bearing part. Thats not what I said at all. I said it doesn't see a lot of force, and it doesn't relative to what the steel used in it can withstand when propperly heat treated.

The main reason for pin holes to elongate isnt always necessarily due to loading, thats an oversimplification. A more accurate statement is that the initial clearance between the pin and hole allowing the pin to hammer the hole is what causes the elongation. If the pin has no way to hammer the hole, i.e., a tight fit, then the force is smoothly transfered to the frame. Sloppy fits cause way more trouble than the actual steel now being used in guns or wether it is cast or forged. Again, its not so much the materials as long as their adequate, its more in the way the parts are put together.

If I were to make a frame from a piece of solid 4140 bar stock and have it heat treated accordingly I defy you to prove it will not last equally as long as one made from a forging. there is no way to do it since both pieces are far far stronger than is needed to deal with the forces generated in a 1911 pistol.

As I said earlier, material selection and component selectiion in engineering is application specific. I also said, all things being equal, sure go with forged. But I stand by my statement that cast will work fine if it is a quality part.

Run the calculations on the forces generated by a recoiling slide hitting the frame area. Their not all that big relative to what the steel can handle.

As far as sliding forces go, well thats a whole different cat entirely. Lets talk lubricant here. No sliding metal parts will last very long of the lubricant isn't able to keep a boundary layer between the two pieces. Again, any forces are here are well within the steels capabilities.

As long as the grain structure is oriented to be strongest where any forces are applied (at the area staring at the crosspin) it matters very little if they go in the wrong direction in the trigger guard or the frontstrap. The issue of strength and structural integrity at these points is just moot, since even "wrong directioned grain" will be plenty strong enough.

Cast frames and slides are hardly the nightmare waiting to happen that you imply. They also aren't going to fall apart from the aftermath of heat treating. Remember, most car cranks are made from castings? They see tremendously more forces per unit of area than any gun frame ever will, and they seem to hold up fine for years and years and years.

It's fine for you to build a premium weapon from forged parts, and I applaud you for those efforts. They are superior to weapons built from cast parts to be sure. But that doesn't mean that guns built from cast parts are inferior, not at all.

As far as i am concerned a forged gun is icing on the cake, not an absolute necessity. I also do not believe that a cast gun is to be shunned. If they were so damn bad, they would be falling apart all over the place since most are made that way. That clearly isn't the case.

Houston,

Never even gave a thought to you maybe attacking me. Like I said, i wasn't too clear there probably.
I have always been kind of leery about the 400 series stainless steels and even some of the Precipitation Hardening variety. Heat treaters around here seem to have problems with them that they just dont have with steel alloys. Thats one reason, like you, I prefer an alloy steel over stainless. Again, mine is a personal bias based on my experiences. Probably not valid, but we do what we know works best.


In a nutshell then. If you use junk castings of poor quality your going to have problems. Use quality components fitted propperly you will not have any problems. It really is just that simple.

P.S. Gyp_c2 The stinger is doing fine. got a total of 500 rounds through it since I got it back. No problems of any kind. Looks fixed to me. :>)



<font size=-1>[ This Message was edited by: Peter Zahn on 2001-07-06 16:19 ]</font>
 

·
Registered
Joined
·
295 Posts
"A properly manufactured forged steel frame or slide will be far stronger and outlast a barstock piece, and they are especially better than a cast piece. Cosmetically, they take a polish much better than castings and in some cases better than barstock."

What about your knives? Are yours "forged"?
 

·
Registered
Joined
·
126 Posts
Anthony-
In brief, Mad Dog Knives are made from roll forged, precision ground bar stock with the grain running the length of the piece.
Stock removal grinding creates the final net shape, but the "near net shape" is, indeed, forged.

If you want a classic example of cast vs. forged strength, take a look at the knives with cast steel blades. They are notorious for precipitating carbide dendrites, and are very weak in impact and flexural strength. In short, they suffer from the same deficiencies as other medium and high carbon steel castings, 1911 frames included.

One knife company relying on cast steel technology has even gone so far as to make the carbide dendrites a selling point, claiming better cutting power as a result of the soft matrix material debrising from around the carbides during cutting. Their own literature notes little difference in performance between heat treated and unheat treated versions of the same blade shape in their cast stainless material. The reason for this is obvious. Little if any carbon remains distributed through the structure in quantities that would allow sufficient hardening and subsequent gains in strength.

Dane- I guess you and I agree in principle, but have arrived at our opinions from different thought processes. That's fine with me, the net result being about the same.

(Maybe Kevin and I should start calling our guns "Hardest Use" guns... :grin: )

Peter- I was referring to your statement about the frame not having a tremendous amount of stress on it.

With regard to calculations, it is not necessary to mathematically calculate effects that are made obvious with simple examination of parts made from differing processes, used under the same conditions.
Quantitative vs. Qualitatative analysis, but I didn't have to tell YOU that... :wink:


_________________
MD Labs
http://www.tacticalforums.com

<font size=-1>[ This Message was edited by: Steve Morrison on 2001-07-06 20:02 ]</font>
 

·
Registered
Joined
·
20 Posts
Speaking as a PE (mechanical) myself I would agree with Steve Morrison.

I cut my teeth in the steel business and I know that (where guns are concerned) forged is best, bar stock second best, and casting should be avoided unless very good QC procedures are in place.

Steve seems to know what he's doing - I'd buy a gun from him !
 

·
Registered
Joined
·
239 Posts
According to Gary Smith of Caspian, they have more failures with the bar stock 1911 frames vs. the cast -- something like 3 vs. 0. I know that they didn't include the double stack frame, as the originals had some problems. Gary did not recommend the extra cost of the bar stock, and instead recommended the cast frame.
 

·
Registered
Joined
·
20 Posts
mmm, interesting, perhaps someone is using low grade bar stock or not applying the correct heat treatment. Certainly goes against accepted thinking on metallurgy.

Of course there have been major advances in steel casting in recent years; Ruger are famous for it, and I prefer their revolvers to S&W !
 

·
Registered
Joined
·
3,831 Posts
Proofs in the pudding as they say. My quess from working on all the major frames is that the Caspian cast is one of the toughest out there for the product we are building. I don't like it's shape or I would use their frames too. Although I think the new Kimber/ et all frames are a superb product and the shape is right IMO.

When a Companty steers you to te less expensive item they sell because it is MORE durable, that should tell you something.

I doubt there is anyone who shoots more documented rounds through their guns than a select few of Caspian's customers. Like I said, "proof's in the pudding". It isn't like those D boys are on the budget for toys. And they are actually the hard use 1911 guys.
 

·
Registered
Joined
·
628 Posts
Dane,

Just curious, what don't you like about the shape of the Caspian frames? I think you mentioned this before somewhere, but I can't recall what you said now :smile:
 
1 - 20 of 27 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top