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Discussion Starter · #1 ·
I bought a 1st gen Colt Bisley in .44-40; only thing is the cylinder I received was .38-40. No matter, I sourced a .44-40 cylinder and got ready to build some loads. Only first I decided to check some measurements. Turns out the barrel diameter(lands) at the muzzle is .420". The cylinder is .452". The forcing cone is chamfered plenty big enough for the bullet do enter.

My concern is the cast bullet diameter is nominally .427". I do not want to blow up the barrel in my "new" Bisley. Can the .427" lead bullet be safely fired in my Colt?
 

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The 44-40 cylinder should be .425-.427 in the throat. Needs to be measured with a ball gauge and micrometer. Your barrel should be slugged by driving a soft lead ball of several thousandths larger than the barrel through it, then measure across the greatest diameter with a micrometer. How is the barrel marked? Does it say COLT FRONTIER SIX SHOOTER? A 44-40 barrel should slug .427. It sounds as though you should take or send your gun to a qualified gunsmith who is familiar with Colt SAAs. Someone like Leveraction Bill who is on our site.
 

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Discussion Starter · #3 ·
The 44-40 cylinder should be .425-.427 in the throat. Needs to be measured with a ball gauge and micrometer. Your barrel should be slugged by driving a soft lead ball of several thousandths larger than the barrel through it, then measure across the greatest diameter with a micrometer. How is the barrel marked? Does it say COLT FRONTIER SIX SHOOTER? A 44-40 barrel should slug .427. It sounds as though you should take or send your gun to a qualified gunsmith who is familiar with Colt SAAs. Someone like Leveraction Bill who is on our site.
I used calibrated steel plugs to measure. Barrel may plug at .427. I will have to check. Was not alarmed by the cylinder oversize especially since it looks like the barrel starts at least as big. Am just concerned with safety and not much by accuracy. There are no Colt gunsmiths in Southern Alabama. I will send it off, if I have to. Thanks.
 

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That .452 diameter of the chamber front would be OK for a .45 but is really big for 44-40 which is noted for being very tight in Colts. About .425 is normal. For my shooters I ream them to .429 because I need the bigger bullets for my 73s. I can see your barrel checking .420 to the top of the lands but that cylinder scares me.
 

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Discussion Starter · #5 ·
That .452 diameter of the chamber front would be OK for a .45 but is really big for 44-40 which is noted for being very tight in Colts. About .425 is normal. For my shooters I ream them to .429 because I need the bigger bullets for my 73s. I can see your barrel checking .420 to the top of the lands but that cylinder scares me.
Here's the story. I bought the Bisley online from a company I often purchase from. When I got it, I could not insert .44-40 snap caps. I did some measuring and got some .38-40 caps, and they fit. Rather than send it back I searched around until I found what is supposed to be a .44-40 cylinder. The caps fit just fine. .45 Colt cartridges do not fit. I have read elsewhere that there are significant variations in cylinder and barrel diameters in the Bisleys. Anyway, I just ordered a Meister barrel slug kit, so I should get better barrel dimensions.
 

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I bought a 1st gen Colt Bisley in .44-40; only thing is the cylinder I received was .38-40. No matter, I sourced a .44-40 cylinder and got ready to build some loads. Only first I decided to check some measurements. Turns out the barrel diameter(lands) at the muzzle is .420". The cylinder is .452". The forcing cone is chamfered plenty big enough for the bullet do enter.

My concern is the cast bullet diameter is nominally .427". I do not want to blow up the barrel in my "new" Bisley. Can the .427" lead bullet be safely fired in my Colt?
When was your gun made? Be careful with that 44-40 cylinder you bought. Without knowing it's date of manufacture it may be earlier than you want for shooting.
 

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A plug gauge reading .420 on the lands is correct. A factory spec sheet I have dated 1922 says rifling grooves are .035” deep. That means the barrel is .427” a gross it’s grooves. That 452 chamber mouth dimenSimon is worrisome.
 
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