There are a handful of different magazine types, but the Accuracy International magazines are the most popular and IMO work the best. If you are wanting to install a detachable magazine kit you will have to get your stock inletted for whatever detachable bottom metal (DBM) kit you choose. I do believe that Stocky's sells stocks already inletted for a particular DBM, usually the Badger, but the stocks are expensive and maybe not necessarily what you are wanting in a stock. I personally use the PTG DBM as not only is it the cheapest but it also uses the AI magazines and supports the magazine very well. I have a HS Precision stock and have installed them in other HS Precision stocks as well as a Bell & Carlson. Those stocks have excellent bedding, but to install a DBM kit you will need a mill because of the amount of aluminum that has to be removed for the DBM to properly fit. Keep in mind that there are NO instructions that come with the kits on how to install them or even a template, so if you don't know what you are doing you can really chew up a stock and still have improper fit. It can be a bit of a pain in the ass to do it yourself, but worth it in the end. Also if you do sell the stock with the DBM you will at least get all of your money back if not a few extra $$ as it does add a bit of value.