Something i've been wondering is that if you can make weapons and buildings out of broken down scrap can you make your own ammo the same way or can you only find or buy it?

No you can not make your own ammo, think is part of the design so you don't use loads of mines to kill an high level enemy to get access to powerful weapon early. In Fallout 3 / NV they used weapon condition.

Seems kinda BS that you can make buildings and mods for high tech energy weapons out of a bunch of tin cans yet not microfusion cells out of some fusion batteries!

Also having problem with low ammo, granted I am playing on survival mode aswell so enemies can soak alot more bullets. Runnung around with 4 different rifle that uses different ammotypes just to get by.

Seems the scrounger perk actually is very good in this game. Very much thinking about taking it.

I'm really liking what they've done with ammo in Fallout 4. It seems much more scarce. For the first time in a Fallout game since 1 & 2, I'm actually having to conserve ammo and scrounge for it.

I was actually sneaking through a raider base this morning and put away my 10mm pistol in favor of a pipe pistol, all because I only had 30 10mm rounds, and I rarely come across them. I could see the raiders were using pipe pistols, so I knew I could replenish my .38 ammo.

I've also found a couple of really good pistols ... and NO ammo for them. I like it.

That's what I like here, you really have to think about engaging and using mines more efficently; I learned that a hard way. xD