.45 ACP Barrel Question

[Bassoneer]

I recently purchased my first .45 ACP, a series 70 Colt Combat Commander in Satin Nickle. I love this gun - shoots great and is very accurate. I sold my .40 XDm to partially fund this purchase, and wanted to keep my number of calibers down to a reasonable number.

My question...the .40 XDm had a match grade barrel, and the wall thickness of the barrel appeared quite thick. The .45 barrel appears to have a thinner wall thickness. Is this my imagination or is it really thinner? How do the internal pressures compare between .40 and .45? Does anybody know what the material properties would be on the two guns (i.e., yield stress, ultimate stress)? Are all .45's similar? The XDm had a steel barrel with black coating, but the .45 Colt has a silver (Stainless?) barrel. Any ideas why it appears thinner? And is this typical?

Thanks, B

[Guest SureShot308]

the .45 barrel will have a thinner wall because it has a bigger hole in it. just like a .40 will have a thinner wall than a 9mm. a .45 has a lower pressure level than a .40 does. I think the average for a .45 is like 21,000 PSI, but a .40 is like 35,000 PSI. the majority of .45 barrels are made from stainless steel. I don't know on the XD though.

[Guest SureShot308]

The XD barrel is carbon steel with a melonite finish.

[Bassoneer]

the .45 barrel will have a thinner wall because it has a bigger hole in it. just like a .40 will have a thinner wall than a 9mm. a .45 has a lower pressure level than a .40 does. I think the average for a .45 is like 21,000 PSI, but a .40 is like 35,000 PSI. the majority of .45 barrels are made from stainless steel. I don't know on the XD though.

Thanks! That explained a lot.

B

[Guest SureShot308]

You are welcome.

[TGO David]

It's also common for a manufacturer to use the same slide between multiple calibers and simply machine the barrels for those different calibers using blanks of the same outside diameter. It reduces cost.