This is my own video guide for collecting all weapons.
All levels are played on Pro difficulty, with the weapons locations and i try to get the Silent Assassin rank at the same time when possible.
Unless it is not possible to get both at the same time, i do the weapon run first then the rank after.
Since the main point of the videos for this achievement is the weapons, feel free to watch at least how to obtain them then how i end the level, if you dont care about the rank then skip the rest of the video. Weapons are listed and timed in the description of each video.
Iyerbeth wrote an excelent guide and this is pretty much the video demo for it (But not an intentional effort from me) Since these are really the best levels to do the achievement in a quiet way, specially on Pro.
All the items i buy in the videos is pretty much all you need to get everything from beginning until the end of the game if you're planning on doing this
achievement on pro with SA Rank. (And the Rank achievement.) However of course the vids can also be used to search and collect weapons in any difficutly you're playing. I hope you enjoy. (A quick note, english is not my native tongue so im sry for any mistakes)
A Vintage Year:
A New Life:
A Murder of Crows:
...Till Death do Us Part:
A Dance With The Devil:
Amendment XXV: