I have wondered if perhaps someone at Ruger decided the Birdshead grip was better suited to 45 acp power levels than .357 power levels. I agree about shooting .38s in it.I wish Ruger would make that same gun, but in 357mag. I would love to have that look, but using 38 Specials in it.
I have a Montado in .357 and have noticed another problem with a 3.75 inch barrel in .357 versus .45 acp. The short ejector rod throws .45 acp brass clear of the gun. Usually the lower pressure .45 acp just falls out when the gun is turned up with the gate open. .357s expand and stick and the ejector will only push the partly out where they must be pulled free. Don't know about the 45 Colt birdsheads.