No. Machine-guns are amusing and fun to shoot. I'm thrilled I bought my MAC-10 in 9mm a few years ago and will probably never get rid of it.
But shooting a .45ACP machine-gun gets very pricey rather quickly. Unless you're selling a .45ACP machine-gun that has some special meaning (like a Thompson or a Grease Gun) I doubt people will eagerly jump for a .45ACP version of a gun they can get in 9mm.
You'll be able to sell it, but I doubt you're going to get what you're looking to ask for it as it'll be a niche purchaser as opposed to your general shooter who just wants a bullet hose to put a smile on their face.
"Our contract called for 16 cases of rifles and ammunition for $10,000 dollars, not a machine gun...........That is our present to the General"-Pike Bishop
“When fascism comes to America, it will be wrapped in the flag and carrying a cross.”