I have a Roy Kasten on my .25 carbine and it helps a bunch. I think his email is rapidroy2002 at yahoo.com
Chuckster, I am also wondering about this for my Sumatra .25 carbine. I've heard excellent things about Neil Clague LDC's and mixed reviews about Wolf LDC's. I don't know if anyone else makes one for the Sumatra.
What are the prices for those LDCs from Neil?
Oddly enough in a land {England} where fire arms are almost banned a very effective (*^% is an option for about £35 pounds, its a sam yang factory part which comes with the rifle!