Deles135, there is no such thing yet. At least I've not seen any. I am presently experimenting with making an insert but it won't be one that you could take out and use the rifle as a 7.5 again. It will be a permanent change if it works. I'm just trying to find a better method to rechamber them than to shorten the shank. Shortening the gas system is part of the problem of getting them to function properly after the conversion. George