I don't own a Tippmann, but I do own a 441 class machine that I use the Tandy polyester 346 thread on. If I am sewing softer leather I can get away with a #25 needle. But if I go to a harder/more dense leather like saddle skirting I got to use a #26 needle with the 346 thread or the thread starts to break or fray. More @Wikipedia
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