Originally Posted by
TGS
Exactly, at least as it was relayed to me. We've got idiots like everyone else (yet our Mk18s seem to do just fine even though they're apparently only for skilled operators who can take the time to fine tune and tinker with them).
The Crane spec Mk18 is not undergassed with 5.56. It's undergassed with weak .223, which is why DD produced commercial market Mk18s with .080" gas ports up until June of 2017 because they didn't want to deal with people shooting excessively weak commercial ammo and making service requests over it; which is why commercially available Mk18s were known to be extremely overgassed to the point of being unreliable when shooting suppressed 5.56. I've shot garden variety .223 through our Mk18s with no discernible difference, and have seen thousands upon thousands of frang through them with no issue, though they're definitely on the lower end of the operating range with frang when unsuppressed.
A properly spec'd Mk18 isn't any more undergassed than an M4 cut down to 11.5". If you think a Mk18 with a .070" gas port is undergassed, then you should think a .062" gas port on a 11.5" is undergassed as well, since .062" was the spec for a 14.5". This is why 11.5" guns are known for having less recoil than commercial Mk18s, because commercial Mk18s were built overgassed as I mentioned.
Dry M4s wouldn't have performed any better, IME, and if they were shooting worn out, dry M4s that day I'll bet money that you and anyone else would chalk it up to poor weapons maintenance as its well known that AR15s in don't run when dry and need lubrication. But since it's Mk18s that choked up when they were dry, now Mk18s are unreliable.
Again, that dog don't hunt.
Everyone here seems to think Mk18s are unreliable for things that would make any other variant of the family choke up as well. Cut the damn barrel in half with a improperly sized gas port and don't lube it. M16, M4: "Oh that's operator error." Mk18? "Oh that gun isn't reliable."
ETA: Just to be clear, I'm really not trying to be a dick with you guys, it's just that the criticisms presented so far just don't many any sense, to the point I want to slam my face into the desk. If anyone showed up to a carbine course with a dry M4 and it malfunctioned, not a single soul would say the M4 is unreliable. They'd say, "hey, you fuckin noob, go put oil on your gun and stop detracting from the class". If you showed up with one of those Dissapator guns that is a 20" M16 cut down to 16", and it didn't work, people would say, "no shit shirlock, what did you expect would happen".
But when people improperly build a Mk18, or run it dry, it's the guns fault. That shit just doesn't make sense. (yes, I realize there was experimentation in the very beginning of GWOT with gas port sizes, but it's 2020, it's pretty much a settled science on what gas port size to use so it's not a legitimate concern these days).