Chamber size?

[44 AMP]

, but if you had .450" throats, that might qualify as broke.

it might, but only if the gun shot too poorly to meet my standards, and I knew the reason was the throat size....

[RoyceP]

Originally Posted by 44 AMP

Yes, and many if not most of them were called "customers"....

The original .45 Colt bullet size was .454". ALL the bullets were lead. Jacketed .45 bullets don't show up until nearly 40 years later with the .45acp with their size of .451/.452".

After WWII, as the popularity of the Single Action revolver started going back up, (due mostly to Hollywood & tv Westerns) and other makers making and selling SA revolves, Colt got back into the market.

During this era, .45 Colt barrel size was reduced to .452" (generally, not everyone did, or did it at the same time), I think, primarily, because more people shooting .45 pistols were using (and able to get) .45acp size slugs.
The "acp" size barrels gave better accuracy with the smaller diameter bullets (and particularly jacketed ones) and the .454" bullets simply didn't care. They squeeze down just fine, and do not create dangerously high pressure doing so.

Eventually, the smaller bore diameter became the defacto industry standard, and still is today.

This is not true. I was buying jacketed bullets from Sierra and Hornady in 45 Colt that were .454" in the early 1980's.

[44 AMP]

I was buying jacketed bullets from Sierra and Hornady in 45 Colt that were .454" in the early 1980's.

Sure, and I was buying .452" jacketed bullets at the same time. Never personally bothered to seek out .454" slugs as my .45 Colts didn't need them, and I also loaded .45acp.

I did not say that .452" for .45 Colt became the established industry standard, I said it became the de facto standard, meaning the most made and most popular in fact.