Using the word clone against the real one would be ok if all the clones were the same , made in the same place and made under the same QC , but they are not , you can buy 4 different clones under different names from 4 different places and they would all be different , buy the same clone under the same name 3months later at it’ll be different again .
where as you can buy 4 genuine Magpul products from 4 different places and they would all the same .
you might get a good clone out of the 4 or you might get 4 shit ones .
IME the genuine CTR requires no shimming for an OEM TM tube unless you want it pretty much like a fixed stock .