Is that true? I can't drive from Minneapolis over to Hudson to meet a guy from Armslist?Private sales across state lines are illegal according to the ATF so this law only applies to purchases from FFLs by out-of-state buyers.
Minnesota allows private sales between Minnesota residents without a background check or anything (but most people want to see a permit to purchase or permit to carry to cover their ass). FFLs MUST do a background check and 4473. Additionally, handgun purchases require a permit to purchase or a permit to carry. Evil black rifles also require a PTP/PTC :shaking:, but you can get a long-guns only PTP if you're 18-21. Most police departments (the ones that issue a PTP) don't know that though and will deny you.
Edit: Apparently that is correct according to FAQ #2: http://www.atf.gov/files/firearms/industry/0501-firearms-top-10-qas.pdf