ar-15 setup with colt .22lr kit and black dog magazine questions

[yongxingfreesty]

How reliable if I use these parts on my le6920?

http://gunbroker.com/Auction/ViewItem.asp?Item=93482836

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http://www.rainierarms.com/?page=shop/detail&product_id=872

Does anyone have this setup? Can you tell me more about it? Thanks bunch