My dad had guns, there was no specification in the will, and the estate is still being parceled out. Only gun I received was a Czech Mauser, and that's because I got my son interested in guns, and he has a a liking for old surplus rifles.
My oldest brother got a Colt 1911, but that was because he had bought it for Dad himself.
My brother in law was the only one stipulated to receive a gun, my dad's single shot 16 gauge High Standard shotgun, but THAT was because my dad and the other son in law didn't receive any guns from my maternal grandfather, and Dad wanted to make sure that didn't happen again.
My other brother has dibs on a S&W .38 Special snubbie, he isn't an avid gun collecter but he figured he would take that one, if we were all picking in rotation to get one. To him, it would be an heirloom, so that's fine with us.
We don't really know the other guy's full story, we don't know if he received another heirloom; or if he said what he did as a way of saying "no, it's ok, I will make the trade". If he's interested in a shooter, wants to sling a lot downrange, or use it as a truck or nightstand gun instead of in a safe, the Glock is a more practical choice.
We're facing a similar, but non-firearm related, situation with Mom's stuff now. She collected antique Fiesta plates, and since I was her ebay buyer, I know how much was paid for these dishes (we might have the equivalent of a couple custom Les Baer 1911's in that collection). Her only concern was that they wouldn't be boxed up and sold for $5 in a yard sale; luckily I was well-enough informed to keep from doing so.