Necro Post:
There has been some discussion about the BCM Gunfighter stock and Paracord/550 cord attachments, here: https://www.m4carbine.net/showthread.php?151670-New-BCM-stock-in-the-works/page24
I took a look at the Proctor sling info (various videos), and noted that putting one of the vinyl tube cinches on (the forward or the rearward connection) was recommended as a retrofit. See: https://www.youtube.com/watch?v=T6agYaKX4XA#t=170
I thought I would put together a quick and stupid tutorial about threading a doubled-up piece of paracord into a .17" diameter tube. I saw this as the only easy way to do this in a flash, and then, like an idiot, tried about four alternative ways to do it. This method should take less than two minutes with paracord, tube, scissors, and thin tool (fork tine) available.
This is the result you want (sort of, I couldn’t find tactical black tubing, so I settled for tactical invisible; slick!):

Take a 1" (or whatever) length of tube:

Pull out the threads at one end of a length of paracord (how much? Perhaps 12" for the rear, longer for the front) for at least double the length of the tube (known as “gutting the paracord”). Do this by pulling back the paracord from the threads (leaving the threads anchored at the other end):

Cut off the threads, and pull on the sheath (the gutted paracord). You now have about 2.5" of gutted cord as a leader. Now fold that in half, and stuff it into the tube:

Use a tool to push the doubled-up gutted cord through the tube:

Keeping the nub at the end anchored, pull the long end through the tube. You now have a gutted sheath in the tube, and a complete portion of paracord along with it:

Even things out. You will have eventually have non-gutted paracord in the tube, and it will be tight (allowing the tube to stay in place when you cinch it in place). You may want to keep the gutted end because it is easier to tie (and retain) a knot with gutted paracord.
