Experimental bronze M1911A1?

[Slater]

I was in the Luke AFB library the other day, browsing their fireams books. The following is extracted from "Colt Automatic Pistols 1896-1955" by Donald Bady (copyrighted 1956):


"In 1932, the Research Section of Springfield Armory decided to investigate the possibility of using die castings for the frame and slide of the 1911A1 pistol. A small number of samples were prepared from a high tensile bronze. They were further machined and fitted. The assembled test pistols were given an endurance trial of 5,000 rounds and the trial report contains a statement that the performance looked promising."

"...Apparently the project was not continued after the original trials; no further references are made to the research in subsequent Armory reports. No specimens of the bronze frame and slide are known and it is doubtful if more than a half-dozen were assembled for this trial."


Not being a metallurgist, why bronze? Was this just a proof-of-concept metal to test the die casting process or would bronze have been the actual material had this concept transitioned to production? Can't imagine bronze being as tough as steel, but who knows?

[Maddog521]

There have been bronze frames used in revolver's. The Ruger collectors fight over them.

[1-DAB]

bronze doesn't rust....steel does.....if you could skip a step (blueing, parkerizing) and have a no rust pistol, that would be handy, no?

why do you think ammo is made out of brass/copper (bronze is copper based too)? it won't go bad if it gets wet. and if you are in a war, you can count on rain and snow.

[diggers4life]

Bronze (depending on what grade) is very hard and slick, perfect for sliding parts such as the frame and slide on a 1911. You definitely would never have problems with galling.

[dfariswheel]

Since this was an experiment to test the possibility of casting major gun parts, I suspect that bronze was chosen for the experiment simply because it is softer and easier to machine than steel.
I'm sure that bronze was used simply for prototype purposes.

Had it looked like a good idea, I'm sure the next step would have been to experiment with cast steel.
It's extremely unlikely that bronze would have been considered for major gun parts production due to the higher cost over steel, and the fact that bronze is always a critical material in wartime and always difficult to get.

[scott53]

I know for a fact that at least one of these pistols survived as I was permited to handle it while conducting research upstairs at Springfield Armory in the late 1980s.

Scott Duff

[Wakethor]

One is currently on display at the Springfield Armory Museum, i was there last week.

[tracyballard]

that is very intriguing. a photo would really be cool.

[oldcanuck]

Are you referring to the M1911A1 manufactured from 'Brastil' ??

Brastil is a corrosion resistant alloy comprised of copper, zinc, and silicon that had a tensile strength of 85,000 psi. According to Clawson, there were at least 2 manufactured (die cast) around 1936. While the experiment was a success, the lack of funding halted futher work. It is pictured in Clawson's first edition page 284.

[1saxman]

Originally Posted by dfariswheel

Since this was an experiment to test the possibility of casting major gun parts, I suspect that bronze was chosen for the experiment simply because it is softer and easier to machine than steel.
I'm sure that bronze was used simply for prototype purposes.

Had it looked like a good idea, I'm sure the next step would have been to experiment with cast steel.
It's extremely unlikely that bronze would have been considered for major gun parts production due to the higher cost over steel, and the fact that bronze is always a critical material in wartime and always difficult to get.

If this were true, they would not have fired the guns, nor would they have fired them for endurance.

[Slater]

Maybe "Brastil" is the "high-tensile bronze" mentioned by Bady?

[Johnny Peppers]

The entire project was to investigate the possibility of building the 1911A1 pistol out of an alloy rather than forged steel parts. The castings were farmed out, but the machining was done by Colt at Springfield Armory's direction. It was quickly noted that there was no time or money saving in machining the Brastil rather than steel. Colt machined one slide and one frame. The pistol survived an endurance test, but the slide cracked when additional rounds were fired. Another slide was machined by Colt and again tested, with no problems from the new slide.
I believe the pistol with two slides were the only ones completely machined, which are in Springfield Armory today.

[ROGER BARTLETT]

The concept of of using bronze for 1911 components was new to me, thanks for the information. The unique qualities of bronze make it ideal for 1911 slides and frames , anyone who has lap fit a 1911 slide to frame knows the difficulties involved in obtaining a perfect 'no shake' fit between two steel sliding surfaces. Bronze offers the following characteristics that lend it to that application; high strength and wear resistance, corrosion resistant and natural lubricity , that's he good news , the bad news is that with prewar machining technology it would have been near impossible to make some of the intricate cuts required in both components ,I can understand why so few exist today. It would be interesting to know how many castings were needed to produce the two or three that made it to the tests. Today's machining and cutting tool technology would eliminate these problems and make the project entirely feasible ,and in my opinion , result in a superior weapon--Think of it - no splotchy fading parko-lubrite finish that drives collectors nuts, just a pleasing mustard patina like a Henry rifle .Regards, Bart

[Wakethor]

Not my picture, but this website has several pictures from the armory, this guy got o go upstairs it's closed off normally now.

Link to the 1911
http://www.pbase.com/mrclark/image/73439213


Full Gallery
http://www.pbase.com/mrclark/springfield_armoury_museum

[Johnny Peppers]

Colt had no problem in machining the Brastil, but the original investigation was to determine if tolerances could be held close enough by die casting to eliminate some of the milling operations, which it didn't.
Neither was Ordnance concerned with a perfect slide to frame fit, as tolerances were allowed to insure operation in less than sterile conditions.

[richyoung]

Originally Posted by Slater

I was in the Luke AFB library the other day, browsing their fireams books. The following is extracted from "Colt Automatic Pistols 1896-1955" by Donald Bady (copyrighted 1956):


"In 1932, the Research Section of Springfield Armory decided to investigate the possibility of using die castings for the frame and slide of the 1911A1 pistol. A small number of samples were prepared from a high tensile bronze. They were further machined and fitted. The assembled test pistols were given an endurance trial of 5,000 rounds and the trial report contains a statement that the performance looked promising."

"...Apparently the project was not continued after the original trials; no further references are made to the research in subsequent Armory reports. No specimens of the bronze frame and slide are known and it is doubtful if more than a half-dozen were assembled for this trial."


Not being a metallurgist, why bronze? Was this just a proof-of-concept metal to test the die casting process or would bronze have been the actual material had this concept transitioned to production? Can't imagine bronze being as tough as steel, but who knows?

Bronze is a term for various alloys of copper and (usually) tin. I have heard of beryllium copper and Coper-Nickel-Selenium bronze being used to make non-sparking tools, so it must be albe to be heat-trated to an acceptible hardness. I suspect the trials were to take advantage of reduced fabrication costs via the die-cast method - at the expense of more expensive raw materials - leveraging on metalurgy already in use for non-sparking tools. I'm certain that between handling gunpowder, gasoline, and working around hydrogen-filled observation balloons in WWI that the military accumulated some experience with non-sparking tools and the alloys they were made of. Unfortunately, the next time that 1911s were mass-produced, the strategic value of copper was too high to use it to make something that could be made out of steel - note the steel pennies, and in some cases, cartridge hulls, of WWII vintage.

[Johnny Peppers]

As noted earlier, the experiment was all about reducing machining costs and time through the use of parts cast to tolerances requiring no further machining. It was found that the material did not stand up to impact and stress as hoped and also contained voids in the castings.
The tests on the Brastil pistols was discontinued in 1934.

[ROGER BARTLETT]

J.P. - The fact that Colt had no trouble machining the castings indicates that the wrong grade of bronze was used ,probably due to the machineability difficulties mentioned earlier. Bronze grades have a broad range of tensile strengths , ranging from 30,000 ppsi [not suitable for either component but fairly easy to machine ] to manganese grades that have tensile strengths up to 110,000 pounds per sq. in.,which would be more than adequate for both parts, but would be almost impossible to machine with 1930's technology. I cannot find the composition of 'Brastil' but I suspect it was near SAE grade no 63 ,which would not have sufficient strength for the application. This may be an idea that's time has come ! Regards, Bart

[Caspian17]

The problem was it didn't save on machining costs as was mentioned, they were trying to cast such a product without machining as much as they had to with their forged counterparts. At the time this was not possible, even today's castings still require machining.

This was not a poke of if bronze is strong enough, we all know it is, but they were made that way to try to pump them out faster and cheaper, which didn't happen.

[Johnny Peppers]

Originally Posted by ROGER BARTLETT

J.P. - The fact that Colt had no trouble machining the castings indicates that the wrong grade of bronze was used ,probably due to the machineability difficulties mentioned earlier.

Ordnance knew exactly what the alloy was, and was ordered from an outside contractor.