I have been told that you shouldn't put a carbine buffer, carbine receiver extention (buffer tube), and carbine telescoping stock on an AR rifle, meaning a 20 inch or longer barreled AR. When I asked why, the only reason given, was that it won't work. Has any one tried this? If it doesn't work, why? Does the AR not function in this configuration? Is it dangerous or damaging to the AR ? I know there are differant weight buffers avaiable, which buffer should be used for a carbine telestock on a rifle assuming it can be done without problems? Thank you for the input.