Apologies if this has been asked before, but I couldn’t find the answers via search or Google.
With KAC SR-15 and SR-30 lowers deviating from mil-spec with ambidextrous bolt releases and mag releases (and a few other areas), would they be compatible with standard mil-spec LPKs from, say, Colt? I understand the unique ambidextrous parts themselves obviously wouldn’t be in the mil-spec LPK, but what about the parts that look standard on the lower (right-side mag release, takedown pins, etc.)? Could a mil-spec right-side magazine release be installed and maintain compatibility with the ambidextrous left-side release, for example? If not, would the left-side ambi release be able to be removed and only a standard right-side release be used?
I ask because I don’t plan on doing any parts replacements, but I like to have back ups for my back ups and have lots of lower parts sitting around. Worst-case scenario, I was wondering if any of them would work.
The ambi parts are pretty much specific. The other parts like the take down pins and FCG, etc are the same as to what could be swapped with Colt parts. The original KAC parts may or may not be considered when talking about RE nuts, trigger guards, etc. You could swap those, but why?
The why of your question was answered in bold. With that being said, most of the parts the OP posted about will never break, and if they do, the lower is probably toast…
As firefighter pointed out, the reason was given. Additionally, the proprietary parts weren’t of concern. It was whether mil-spec parts would work or not.
I contacted KAC directly and was told mil-spec parts will indeed work and be compatible with KAC’s ambi parts, so the system should continue working as designed. That said, some KAC parts (bolt catch) are beefed up to better handle the ambidextrous controls, so I’d think it would be advisable to use KAC parts in any possible scenario if possible.
Either way, in a pinch, mil-spec parts will do. Woop.