RRA AR pistol lowers question

[Spike59]

I have always wanted to buy a RRA AR pistol with the idea of converting it to a SBR one day. I was looking at the RRA on-line catalog and I thought that the buffer tube ass. seemed to be smaller in diameter than a standard .223. I called RRA and the person who I talked to stated that it was a dedicated pistol tube and could not be converted to a rifle tube! Is this true? Please say it is not so! Has anyone here ever SBR'd a RRA lower?

[pro2]

I got a rock river arms pistol lower a couple of years ago and made it into an sbr. I can't tell you if their latest dedicated lowers without the mag block have the same receiver extension as the previous generation though. When I spoke to the techs at rock river they said that blue loctite was used on the threads. To remove it, I used an electric heat gun and a wrench and then replaced it with a carbine buffer tube.