I want to start work on a custom .500 whisper project. I will be slinging very heavy slugs at subsonic velocities. Due to the brass that I was going to use, I was going to use an action I already have which is a 700 short in .222. The bolt face is right, the price is right (free), etc BUT the action is not long enough, I need to accommodate a 3.0-3.1" cartridge which means I will have to heavily mod the 700 short. There is also indication that this gun might be too valuable to cut up and I might be better to sell it and buy what I really need. The thought came to mind to see if I can just sell my complete .222 rifle and get a new 700 long with a .222 or .223 (same) bolt face? I have no need to buy new but not sure which direction to go. I will list a few specifics that I need. I should mention that I own a machine shop so some mods including the barrel chambering and threading will be done here. 1. Must be an action that I can get parts for, 700 seems perfect here 2. Must be able to mod the action for clip and make or buy removable mags 3. Common enough geometry that I can find a tactical stock to work. 4. CHEAP. Build is on a budget but I don't need junk. If the 700 is indeed a smart direction to go, I would really like to find resources of places to shop for parts, possibly any resources for used actions or forums that specialize in the 700. I imagine if I could get a long action with mag feed and a bolt face close to what I need, I can probably work it from there.