I will be adding a .458 Socom to my collection. I'm debating whether to just add a complete upper or a complete upper and lower build. I understand about the .458 being compatible with the standard AR lower. I have to think the stock lower will take a beating from the extra stress. The uppers I've seen seem to just open up the ejection port and call it good to go. But I have seen where companies like CMMG have started building purpose built lowers (the Anvil). Would like feedback from you other .458 Socom owners.