I always draw my blueprints out by hand. You have to print out the blueprint from your computer, and you will have to manually scale it up using a mathimatical equasion, and drawing each line of the weapon to scale. The tutorial explains how to do the mathimatical equasion.
As for the DMR, Spase does have blueprints, but they are very inaccurate. Other then those, there are no blueprints out there. I have some, but I drew them out by hand, and can not share them because they are too large to properly scan.