Your Browser is OutdatedSo this will fit on a mil spec Ar15 lower and designed for 5.56/223? Able to properly cycle a 5” barrel with included buffer and spring? — 1 Answer
Maxim Defense makes CQB and PQD stocks and braces that all have the same general design. This product is a stock and can only be mounted on firearms with barrels +16" in length. Mounting this Maxim CQB stock on firearms with barrels shorter than 16" will change the NFA classification of your firearm and make it subject to further NFA regulation.
For a 5" barrel, check out the Maxim Defense CQB Pistol PDW Brace - it uses a standard BCG in conjunction with the proprietary Maxim buffer and buffer spring included with the brace.
https://www.opticsplanet.com/maxim-defense-industries-cqb-pistol-pdw-brace-for-ar15-hxcvq.html