Re: 7 wsm
ANY action that has NEVER been assembled as a rifle can be used for a pistol build. When you purchase a NEW action, Lawton, Stiller, Bat or any of the others, the FFL dealer that does the paper work SHOULD list the item as a reciever, not a rifle or a pistol. Then it is up to you what you do with it. BUT once a rifle ALWAYS a rifle, you can convert a pistol to a rifle but NOT the other way.
To be a pistol according to the BATF the barrel must be less than 16" and/OR the total length must be less than 26".
If the barrel is longer than 16" AND the overall length is 26" or more it is a rifle to the BATF, regardless of the type of stock you put on it.
If you have an XP 100 action with a 16 1/2" barrel and the overall length of 26 1/4" with a pistol stock on it, to the BATF it is a short stocked rifle. Which does NOT require any BATF stamp, BUT may or may not be regulated by your state or local Government.
This is the best explanation I can give from the research I have done.
"How a politician stands on the Second Amendment tells you how he or she views you as an individual... as a trustworthy and productive citizen, or as part of an unruly crowd that needs to be lorded, controlled, supervised, and taken care of."
--Rep. Suzanna Gratia Hupp (TX)