The shock cord is 3/16" and I used that size initially because that's what I had on hand. Actually, I had some of that cheap mini shock cord that they sell at the dollar store and it made me realize that, with high quality shock cord, it was feasible to make a bungee-type belt.
I bought it from
https://sgtknots.com/collections/shock-cord. I see that SGT KNOTS is also on Amazon which may save shipping costs or effect availability of size and color. Lately, if I can go around Amazon and buy directly from the supplier that's what I prefer. Amazon is just too big IMO.
SGT K sells a few different grades of shock cord. I've been very satisfied with their polyester cord but I did buy a few yards of the Dyneema shock cord and It's great. When I bought it, they offered the dyneema version by the foot, but I only see it offered in 500 foot rolls now. Maybe contact them and ask if it's available by the foot. It's really good stuff, but 500 feet is $$$!
Keep in mind that my Recons were the 1st prototypes Mark made. They never had the rubber coating on those. They are the medium size and at one point I wanted to try a production model in Small. I did remove the rubber coating on it but I soon realized that I liked the prototypes better than the production models so I sold it...Never really hunted out of it much, if at all. And, as
@shmeags said, it's best to check the plats for any rough edges which would be an easy fix with a file. The old coating probably had a slight impediment in how easily the straps slid but I never really gave that coating a fair test. Once I heard the noise they made, I immediately removed the coating. I assume the new coating is not an issue but I can't comment on it because I've never had it in hand. I've had no wear whatsoever on the webbing from the plates.
If there's anything that restricts how well the straps slide through the plates, it would be the way the belt is anchored to the plates. The plastic tri-slide buckle thing does kinda pinch down on the straps between it and the plates. Which is another reason why I prefer a bungee belt. It eliminates the tri-slide.
And I'm going to disagree with guys that are removing the stitching. Mark and I went back and forth trying to decide if the stitching helped or hurt the design. The Anderson had the stitches so we figured they must have had a purpose. But we tried them both ways, with and without. If the straps equalized better without the stitching, it was negligible to the point we couldn't notice a difference. But what we did notice was the straps could easily become twisted and disoriented when the sling wasn't worn...in the laundry, storage tub, or pack. I would not remove the stitching.