What I mean by this is what combinations of ammo are "like" enough to be shot in the same firearm? For example, a gun capable of using a .357-Magnum round can also use a .38-Special round. What other "like" ammo is there?

a gun chambered for .357 mag will fire 38 specials, but a gun chambered for 38 special will not fire .357 mag.

 

gun chambered for 44 mag will also fire 44 special

 

there are also a bunch of guns out on the market now that will fire a bunch of different ammo out the same barrel, the smith and wesson governor comes to mind, it will shot .410 shotgun shells, 45 ACP, 45 colt, ( and i think 45gap and 45ar )

.44 magnum "like" .44SW

gun chambered for 44 mag will also fire 44 special

 

...and .44 Russian, and .44 American

 

We just did a thread on this not too long ago, but darned if I can figure out what criteria to use for a search.

10mm can fire .40S&W?

No, it headspaces off the mouth

10mm can fire .40S&W?

 

In a revolver - NOT a semi-auto

.223 can be safely fired in a 5.56 chamber, the opposite is not necessarily true.

.308 can shoot a 7.62 nato?

.308 can shoot a 7.62 nato?

 

...but again, should not be the other way round.