I have a chance to buy a Vltor stock for a fairly cheap price, but I do not know what brand my receiver extension is. It is 1.170" OD. Is it mil spec or not? It would not be a good deal if I have to buy another RE to be able to use it.

I have looked at about 150 thread titles, read all the stock threads, and done several searches but haven't found the OD's for mil spec or other RE's. I even downloaded the CAD file but found I do not have the program to use it once  it is unzipped. I thought I had seen it mentioned a month or so back but don't remember where.

Danny

Here's a table listing measurements: