your evil twin said:
I've got to say, they did choose an interesting relatively unknown weapon to base the gauss rifle on, so I do have to give Bethesda a bit of Kudos there.
Because inserting slightly tweaked WW2 weapons into Fallout is a kudos-worthy achievement.
It also explains where they got the idea for the massive box magazine - the L39 had a huge magazine because it had ten 20mm rounds. For the gauss rifle, they turned that idea on its head and had it instead contain a thousand classic 2mm rounds! (Plausible if you assume that 2mm rounds are very short as well as very thin, possibly like tiny ball bearings rather than needles.)
Not only would the massive magazine placed laterally completely debalance a hand-held precision weapon, it's also completely pointless if you can just as easily store the required ammo in the buttstock or just about anywhere on the gun (if it's only holding bullets with the energy source placed separately).
As for the purpose of the crank, I figured there were two possible functions:
1) A sort of release for removing/inserting the huge magazine on the right hand side. (It looks to me like that might have been its original purpose on the L39 too.)
2) A means of removing the power source assembly for maintenence. To actually access the chamber that the energy cells get inserted into.
The crank on the original gun was used to cock the weapon and was used because the action is exceptionally long and a small crank on an already massive weapon that can only be fired when deployed doesn't hinder the operator in any way.
Magazine release? Give me a break. 2) makes a bit more sense except the maintenance tool would not be permanently attached to the gun. Also, the crank can't actually be turned while the magazine is in place (because it's in the way).
Also, when adapting the weapon to a more manageable size all they did was shrink the original model without paying attention to the fact that the butt-stock length needs to stay pretty much the same - this variant practically has no butt-stock (having been lost in the shrink process) - first sniper rifle I've seen that doesn't have one.
Now let me explain the kudos-worthy design process to you as it happened over at Beth HQ.
1) Leaf through gun encyclopedia for an obscure gun.
2) Pick a WW2 anti-tank rifle because it's the obvious choice for the base model for the pinnacle of weapon technology in the future. (it even has a crank! awesome retro!)
3) Shrink it to hand-held size paying absolutely no attention to weapon ergonomy.
3) Slap some electromagnets around the barrel.
4) Slap on a scope because it's supposed to be a sniper rifle, move the magazine to the side because the scope has to be on top of course.
5) Rely on fans to retcon an explanation for your lack of creativity.
...
Profit!