How many different calibers do you own?
i really don't know - i haven't counted in probably a year or so. maybe 50?
If you own many different calibers, is there a reason, other than collecting?
yes, there is a reason.
the 22-250 is for prairie dogs, but sometimes the barrel gets too hot, so i got a 223 to shoot while the 22-250 was cooling. well, if i'm going to go to the trouble of having a 223, i might as well also have an ar-15. the ar-15 works pretty well to train novice shooters with because of light recoil and inherent accuracy, but new shooters should also know how to work a bolt gun. so the 221 came for that purpose, and doubled as a fantastic prairie dog gun. and etc.
anyway, that line of reasoning is what got me to where i am. i furthered that by developing other specific needs: i decided i wanted to hunt deer, so the 7 rem mag came, and it is a fantastic deer killer.
but what to use for elk? a 338 win mag, of course.
but what if i'm just hunting cow elk? seems like a 308 win will work great.
but what of dark timber, close range elk? surely a custom 8x57 would fill in there.
and antelope? a 25-06.
mule deer in river breaks? a 264 win mag.
mule deer on prairie? a 300 win mag.
whitetails on prairie? a 300 wsm.
on river breaks? 7-08.
in timber? 30-30.
what about cross canyon timber shots? 300 savage.
how about a classic deer gun? sure, 270.
short action? 260.
long action? 30-06.
then there's the 'specifics' niche: i need to drive a 160 grain bullet at 3300 f/s: 7 rum.
i just don't know what to do with all of this ramshot hunter. 257 roberts.
i got this smokin' deal on this nightforce scope so i bought it, but i don't have anything to put it on. 338 rum.
then there are the needs addressed by having multiple platforms:
i think i like the idea of a 30 carbine, but don't know what else to do with it outside of punching close range paper because it is kinda small. answer: blackhawk.
you know, this marlin 1895 45-70 is a lot of fun, but i wonder if i can get some more use out of the cartridge. answer: yep. bfr.
and then there is the 'test the theory' specialties that require guns. for example, this marlin in 357 sure makes the 357 mag a powerhouse of a cartridge. oh really? well, i'll pick up this 686 over to the gunstore, and let's put 'em over the chrony...
so, you see... it isn't hard, and doesn't take that long to get a lot of guns, and a lot of chamberings.