All my throwbag failures occurred because of faulty sewing. You could see where the seam was only about 1/16" from the edge of the material. It doesn't take but one or two hard landings to burst it right open. I had one burst last week on the fourth throw of its life. A simple solution would be to double-stitch it making one pass, then another about 1/4" from it. That way, if one seam burst, at least there'd be another to back it up. I am talking to my daughter about making one using a circle of canvas. I'll draw the lines where ordinarily it would be cut and seamed, but rather than cut it, just sew along the lines. the excess, puckered canvas will be inside the bag, with no opening to burst. If the seams fail, the bag will bulge out, but no shot will be lost. Just add the old electrical tape, and keep chunking.