I’m looking to replace my standard internally fed magazine that loads through the breech on my .308 SA Rem 700 with a detachable box mag. set up. There are several available from cheap Magpul polymer to parts costing 300+ which is a bit costly for me. What’s good for an AICS mag set up? I’d like to stay away from proprietary mags. I’m looking at 2-3 different manufacturers. Feeding reliability is key. If I’ve got to mod the stock a little no prob. it’s a Bell & Carson Varmint/Tactical. Thanks guys.