While I understand the notion of multiple calibers in one firearm, I cannot overlook the fact the firearm is designed for the one caliber and any variation may have safety concerns. I admit to being a stickler for safety and have had a negative experience with a fellow shooter using the wrong ammo in his handgun.
My late father-in-laws NM Blackhawk ended up with my son. Elmer (FIL) didn't shoot it hardly at all, and when Jake (son) shot it the brass wouldn't eject. He left it with me to sort out and I found the throats were horribly undersized, so I used John Taffins technique to expand them and after that it works like new money. I have read this is a common problem among the Ruger 30carbine revolvers.
Well, I thought it was Taffin's article I read some years ago but I can't seem to find it now. What the author said was that he used a dowel rod with a slit sawn into one end and a piece of emery cloth strap wrapped through the slot and around the rod which he then inserted into the chamber throat and turned the rod thus removing steel until sized correctly. To measure the throat he used the bullet he would be loading and shooting. The bullet should not fall through the throat but push through with a very small effort. For the 30 carbine I used a 1/4" brass rod and hand turned it on the first chamber, but was afraid of blisters, so I chucked the rod in a cordless drill to open the other 5 chamber throats. I went carefully because I didn't want to remove too much throat. I have don't this on my custom 45LC Vaquero also without the drill and it has worked flawlessly.
Thank y'all for answering my questions. I would have never thought of using 327 Fed ammo in this gun, and don't intend to now. The possibility was brought up so I asked more about it. It seems possible that they "might work", but I'm not gonna chance any harm to this fine old piece, or myself.
I hope too this has helped the OP, and he doesn't feel like his thread was hijacked.
Thanks again y'all