I noticed in Fallout: New Vegas that many weapons were from the 50's [ex. 9mm Submachinegun = Grease Gun from WW2]. How did these weapons get here? Most of these weapons came out of use by the late 50's-70's, how could it have survived 200+ years too appear in fallout? Just a thought...

People like real life weapons in the game, but modern weapons don't fit very well. WW2 weapons are pre-divergence and therefore always existed in Fallout.

The 9mm SMG in New Vegas is not a 200+ year old weapon, the Gun Runners are constantly creating new weapons, and chambering them in common calibres of the area.

The Service Rifle is another example of this, Gun Runner NPC's mention increasing Service Rifle production due to higher NCR quotas for the war.

For the weapons themselves, the designs mostly stayed the same right up to the Great War, the R91 Assault Rifle in Fallout 3 is proof of this. It's the standard issue rifle of the US Army, but it looks like an H&K G3 with a wooden endstock.

The Chinese did the same thing; their assault rifle, the Type 93, is very similar to the AK-47. Their Pistol looks like a Mauser Broomhandle, which was designed by the Germans before WW1.

Its due to the divergence of the timeline. Which kept the world of Fallout stuck in the 50s tech capablility.

And before you say "But there's laser weapons!" there is an answer for that too, the laser weapons and robots are a result of the 50s idea of the "World of Tommorow!".

Most likely they are assuming that the extreme bellicosity of the Federal Government meant that not only were military grade weapons more widely distributed, but the War Department was stockpiling or selling obsolete weapons to the public rather than destroying them. In the real world US it was not uncommon for High Schools to have shooting teams and programs to train kids in rifle marksmanship under JROTC well into the 60s. Before WW2 you could purchase a brand new service rifle from the Federal arsenals that made them through the DCM program. In the Fallout world that was probably taken to a extreme....you could buy all kinds of guns as long as the FBI didn't think you were a commie. And by the time the War happened the Feds were fighting riots and worse all across the country so there were troops deployed everywhere.

And with some popular designs....the Gun Runner are probably making new copies to see to whoever can afford them.

Major thanks too GT409 for clearing this up. Im really not sure about Tiberious67's theorie though, that, or I should really brush up on my fallout history. :vaultboy: