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Discussion Starter · #1 ·
I have been rereading, “You are Now Entering the Great Colt Manufacturing Plant at Hartford,” a chapter in A Century of Achievement, 1836-1936, by Arthur Ulrich and published in 1937. (This is also republished in A History of the Colt Revolver, 1940, by Charles T. Haven and Frank F. Belden.)

It is a marvelous read for anyone with interest in the prewar Colts, how they were made, and in the degree of quality control exercised in both machine and handwork in the early 1930s. Even allowing for the Colt PR hyperbole, it is an impressive read. Many of the employees had been in place for over 20 or 30 years working on the same painstaking processes. One guy mentioned had been at it for over 60 years! I was also impressed to read that 9/10ths of the guns pass final inspection, meaning that 10% didn’t make it. (And this is after earlier defects are rejected throughout the manufacturing process.)

Among many passages that caught my eye: “Since every barrel tapers inside slightly to the muzzle end, a generous amount of finish reaming is necessary. The target .38s for example must come within half a thousandth of the exact diameter.” I am particularly curious as to the “every bbl tapers slightly to the muzzle end.” It seems to me that I have read on this forum that the tapering bbl diameter is thought to account for the unique accuracy of the Python, but the passage I quote would seem to indicate that all bbls, at least prewar, have this taper.

Comments? Is the tapering unique to prewar Colts and the postwar Python, or is it common to all Colts or even to all revolvers in general?
 

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interesting thread, sorry but i cant answer the question.however those were the glory years for colt revolvers when no expense was spared to produce the best product.is that book currently available and if so where??
 

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Discussion Starter · #3 ·
I got both books from an internet used book service called www.abebooks.com. It ties together used bookstores from all over the world.

If I were only going to buy one of the two books I mentioned, I'd buy A History of the Colt Revolver because it has more information and is a large book. Still, a Century of Achievement, while quite short, is very nicely done, and has the in-production line-up of models as of the 1930s. (I think it comes in paper as well as hardcover, which is what I have.) It also has a chapter on how to shoot pistols by Charles Askins. If you like the prewar Colts, I'm sure you'd enjoy reading about how they were made. It's very impressive.
 

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Discussion Starter · #4 ·
[ QUOTE ]
Is the tapering unique to prewar Colts and the postwar Python, or is it common to all Colts or even to all revolvers in general?

[/ QUOTE ]

Anyone have any knowledge or thoughts on this?
 

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As far as I know, this was the way Colt barrels were made, and was said to be the reason for the superior accuracy of Colt revolvers. (That, and the second hand taking out all the cyliner play at the moment of firing.)
 

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[ QUOTE ]

But how did they put the taper in?

[/ QUOTE ] i would assume the bbl`s were bored slightly undersized, and reamed to final i.d. with a tapered reamer of correct o.d. i would also assume this would require a seperate reamer for each bbl length, unless short bbl`s were cut from longer blanks. i know the old cap and ball revolvers had a gain twist, which looks to me like it would be hard to replicate but was common practice in that era.
 

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Discussion Starter · #8 ·
Here’s the description of the making of the interior of the barrel from the account I refer to above:

BEGIN

... The barrel, like all other machine parts, is first heat treated to insure good machine-ability. Then it is pickled in an acid bath to remove loose scale. A flow of oil of 500 lbs pressure forces the fine chips out as fast as the cutting edge takes them off. The drilling process is delicate. It takes about ten minutes to drill a 5” barrel. One can honestly say that a Colt barrel “gets a lot of reaming.” A barrel is machine reamed many times, each reaming making the barrel hole a thousandth or so larger.

Since every barrel tapers slightly toward the muzzle end, a generous amount of finish reaming is necessary. The target .38’s for instance must come within half a thousandth of the exact diameter. Sometimes it is necessary to finish ream a barrel four or five times to acquire this exactness. All along the line, I hold up to the light the barrel that is going into the gun they’re building for me. Now they are putting it through the leading and polishing operation. They squirt on a drop or two of hot lead and wipe it through. The hot lead takes out any microscopic ridges and gives the inside of the barrel a high polish. We go to a rifling machine. In rifling, Colt acknowledges no superior. Inserted into the machine, the barrel is rifled. It takes about 20 minutes. Two barrels are on the same machine, each taking its turn as the cam throws the barrel over for its next cut. I hold it to the light again and see a spiral ribbon exactly three and one-half thousandths deep, a left hand twist that will speed a bullet accurately to its mark. It is a beautiful sight. No other word describes it...

END

From A Century of Achievement, 1836 – 1936, copyright 1937, pp. 65-66.

Icdux1, is that description consistent with your thinking? (Not being a machinist, or understanding the process well, I don’t know, but I think it is.) Also, does “finish reaming” mean “reaming by hand”? I assume it does.

I wonder how this compares with the way barrels are made today?

Also, what is a "gain twist"? Does it mean the twist rate increases with the taper?
 

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And people wonder why we buy the old Colts.

Works of the master gunmakers art they are!

Thanks for the insightful post.
 

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To give further credence to this taper bore information,Pate has a photo in his book of an Officer's Model in .38 Special,one of the variety of Colts bought by the panicked Brits when they thought Operation Sea Lion was about to happen.

Gun was converted to the British 38/200 round(.38 S&W-not .38 Special). The photo shows the muzzle,that has been reamed inward a couple of inches. I guess the Brits worried about the larger .360-.362 bullet screaming along at its 600-650 fps. might not pass through the tight .355 bore!!!

Don't know if this was done on the 5" O.P.s built for the Brits in .38/200?

Colt used the same size bores for .38 Special and.38 S&W(.38 Colt N.Police),for the .38/40 and 41 Colt,the 44/40 and .44 Special,as well as the .45 Colt/455 Eley. They did change to .452 for the .45 acp in the 1917s. Think same was true for .32 N.Police and the 32/20.

Talking pre war guns in the above.

Bud
 

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[ QUOTE ]
Also, what is a "gain twist"? Does it mean the twist rate increases with the taper?


[/ QUOTE ]

It increases over the length of the barrel.

Tom
 

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gain twist starts out slow and increases. it gave the soft pure lead projectile a chance to start down the bore without "stripping" the rifleing. as to todays methods i would say ruger makes more bbl`s in a day than colt did in a week. examine the outside of a mini 14 bbl and you will get an idea /forums/images/graemlins/wink.gif
 

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Discussion Starter · #13 ·
Thanks for the comments, guys. I appreciate the feedback and info. I sure do love the prewar revos.

If there is interest, I was thinking I could scan the account of the factory visit that I have been quoting and email it. Probably take me a coupla days to get around to it.
 

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thanks for the generous offer but you have already "sold" me that book as soon as i can find one /forums/images/graemlins/wink.gifi just about have wilsons american legend memorized. my poor wife just looks at me strangly and ask`s" are you reading THAT book AGAIN??"
 

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Every Colt person should have a copy of "A Century of Achievement." They show up on eBay regularly, and vary greatly in selling price.
 
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