If it's the one I'm thinking of with the sleeve, then there was a problem with the first batch which resulted in the sleeve stripping with each shot, rather than over prolonged use (you can buy replacements, but obviously 1 per shot is a little excessive).
I understand the problem has been fixed and they work ok now, but just have the standard bolt meself.
I understand the problem has been fixed and they work ok now, but just have the standard bolt meself.