I own a 3d printing business on the side, so I got curious and loaded it into the slicer. I didn't bother going through his build guide, so this is rough numbers. Looks like several parts are either/or depending on caliber, but I'm sure there are several parts you have to print multiples of.
It's just about 6kg of filament, so about 6 rolls. I buy mine in bulk for ~$8/kg, depending on what my suppliers can get. I'm not a big shop, so not amazing prices. So, ~$50 without considering electricity and time (which is going to cost A LOT if you use someone to print this).
Using PLA, which, as stated, would not be preferred since you only get to about 55C before glass transition, it's 7.3 days of printing.
PETG is slightly better on temp, but still only about 75C, and slightly higher costs ($1-2/roll).
I would probably go ASA or ABS to get 100C glass transition temp, and possibly carbon fiber reinforced for any part that might deal with impact. Costs jump significantly on filament ($20/kg on average), but ASA and ABS are more dense so you drop down below 5kg of filament. It also cuts a full day of printing.
Damn, after loading it all up I kind of want to design some barrels and print it all as a cool looking prop for my shop.
edit: Oh, also, someone know a good lawyer for when the ATF kicks down my door?
