Was pulling a guarder SP120 for about 25k rounds... at about 15 rounds per second in a version 2 with a duracon piston head and brass cylinder head (No cushioning)
now holding up to a SP130, with no signs of it being ready to explode yet.
So whoever says not to use this with an M120... you're wrong, it holds up fine.
Only sign of wear is that the second to last tooth is completely gone... which is usual.
Grease vents in guide-rails
Rating: [5 of 5 Stars!]