Shooting .45 acp New vs Old

Is there enough difference (muzzle velocity and chamber pressure) between WWI and modern .45 acp that I should worry about shooting modern ammunition in my 1918 M1911 Colt? Some on other boards have suggested the older metalurgy cannot withstand modern pressures. Is this internet paranoia hype, or should I be extra cautious? I’m talking about off-the-shelf 230 gr ball.
Thanks much, lee

None whatsoever. I have fired a WWI M1911 pistol (Colt) for many years without incident, and still use it. Many thousands of rounds have gone through it. I have chronographed WWI-era .45 ACP ball ammunition, and its MV is the same as modern .45 ACP ball ammunition which would indicate similar chamber pressures and recoil impulse. Many WWI-issue M1911 pistols were refinished and re-issued by the US Government during WWII. That would not have been done were there any safety or performance concerns. Assuming your M1911 is in sound condition, fire away.

Not so for the M1911’s predecessor, the Colt Model 1905. It did use a similar cartridge design, but with a lighter 200 grain .45 bullet. Due to the way in which the slide was affixed to the frame, using a cross key, it could be damaged by extensive firing of heavier 230 grain loads.

That’s good to hear. I was pretty sure that was the case but wanted to be positive about the pressures. I hope your reply helps others as well.