Hi I've always wished for more homemade post apocalyptic guns and clothing in Fallout. I just wanted to hear other peoples ideas and thoughts.
Do you want them? How rare should they be? should there be rare unique ammo types sold by one person or group of people?
I've always felt that in isolated communities in the wasteland would might hand load their own regional "wildcat" ammo. Examples might be 11mm round or 10 Gauge buckshot. A group that had access to unique materials would have unique weapons and ammo. Personally I roleplay pretty hard with my characters, It frustrates me to only have access to pre-war items in a post-war world. The fallout universe is a harsh one where only the most adaptable survive. I was forced down this line of thought by the unique weapons from Metro 2033. Having a raider band attack you with shiny 10mm pistols erodes my suspension of disbelief.
How do you feel about this?

I am not sure if they have the infrastructure to manufacture even basic ammo. I could see modifying existing rounds, but creating their own is another story.

but in 200 years since the war knowledge of handloading and gunsmithing clearly has survived. Also there is gonna be a lot more ammuntion left over then weapons to fire them so makeshift zip guns would be manufactured locally in less than ideal conditions. Its suprisingly easy to make a gun, it won't necessarily be very accurate or safe but over time you would learn to make better quality weapons. This would be a valuable skill to the community and in a lot of cases might be vital to the communities survival. like you pointed out actually manufacturing ammo would be the prohibitive factor in a lot of situations.

It's pretty funny anyway, that all this ammo from the old world is still somehow available and useable, after 200 years. As anyone who is well familiar with weapons and ammunition can tell you, ammunition that has been laying around for years, particularly in uncontrolled climate conditions like this stuff from all the rusty containers, moldy boxes and burned-out buildings left behind from the war- basically becomes unstable to unusable, pretty quickly. Even ammunition kept in fairly good storage conditions eventually becomes unstable and/or unusable after 20 years or more, if not sooner. 200 years? Mostly exposed to the elements and vagaries of temperature and moisture? Be lucky if even one round would still fire.

Ah, nostalgia, horrid memories of that horrible atrocity to mankind's knack at killing each-other, the Pipe Rifle.