The 10mm, 45 ACp, and 38 Super are all longer and can be chambered in the 1911 guns.
the 40 is a cut back version of the 10mm to be more PC at the FBI and will fit in all guns designed to shoot the 9X19 round and giving ballistics similar to the 185 grain 45 ACP rounds.
The 40 with 2 to 5 more rounds in a double stact than your standard 1911.
The 10mm was the Cooper Brain Child and he wanted something more powerful than 45 in the 41 Mag range that ould be housed in the 1911 frame. The FBI adopted it and then found it was too much for most of their smaller agents and loaded it down to 40 levels and then came up with the 40 S&W. there we silly groups screaming about over penitration and protecting the citizens that also effected the designing of the 40. This is why at the Bank shoot out in Hollywood the police with shotguns were not able to stop the robbers. They had #4 bird shot in stead of buck and slugs but that is a different posting.
I am not exactly a 1911 fan and prefer an different design. But own 9, 40, and 45 semi auto handguns by the same maker.
All three work well and knowing now and had to do it all over again I would have just stuck to one of the three and spent the time and money into getting really good and shooting at matches rather than owning basiclly the same gun that eats different types of ammo, requires different projectiles, cases, holsters, and magazines.
If you are happy with the 45 and the 1911 frame. Keep it.
If you want the power of the 10mm for hunting then you have two options of 10mm or 400 Corbon (45ACP necked to 40)
If you want a 40 for a smaller carry gun get a double or single stacked 9X19 sized gun (comander sized or smaller) Take advantage of the smaller case with a smaller sized gun that can hold more rounds.
Other than that all the handgun rounds between the 9, 357 sig, 38 super, 40, 10mm, 41 AE, 45 Glock, 45 ACP loaded with the same designed bullet - FMJ or Hollow point rate with in a few % points of each other on the one stop shot. What I mean is FMJ out of a 9mm or 45 are about 62-64% and with the same hollow point the Gold dot, golden saber, SXT, hornady all are going to be with in a few points of each other between calibers if factory loadings.