im not planning on doing this just curious what the general opinion of buying 10 round mags for 458 socom and changing the follower to 556 and using them as 30 rounds?
From the 458 Socom wikipedia page...”As noted above, the cartridge was designed to be 100% compatible with the M4 platform. This included the buffer, buffer spring, NATO magazines, many aftermarket .223/5.56 magazines, and magazine well. In .223/5.56 caliber, cartridges stack in a staggered (double stack) fashion. However, with the much larger .458 SOCOM, rounds "single stack" without any modification to the standard GI magazine feed lips or follower. A standard 20-round 5.56mm NATO magazine can hold seven .458 SOCOM rounds and a standard 30-round 5.56mm NATO magazine can hold ten .458 SOCOM rounds.” Other than the legality, it sounds doable...
so it is definitely doable, i only thought about the follower swab because 458 socom specific mags have a follower with an indent the shape of a 458 round.