Why: 
Bulk converting to 300blk would hurt my fingers for days after because I would do the final trim using a FA trimmer and very little case would stick out to hold onto. So I wanted some simple soft jaws to firmly hold the cases, indexing off the rear of the case reducing the fiddle factor and time. These only put pressure down by the web and rim of the case so no problem with deforming your case. Goal was to only add a few seconds to the final trimming cycle

Fit:
Meant to be a friction fit onto the jaws of the Visegrips so YMMV depending on your pair of 7WR's and printer. You could easily expand one of the sides and glue in a magnet if you really wanted an even slicker solution.

Filament:
Original plan was to print it in 95A TPU, but the friction fit onto the jaws works well and holds very well with regular PLA.

Print Notes:
100% infill = under 3grams

Files:
Uploaded STL and STEP if you want to edit. It's far from elegantly modeled, but all the geometry that is needed is there.

Printables Tags: 223; 300blk; cases; reloading; brass; visegrip