You're comparing apples to oranges.
The MK14 was never built to be the most accurate rig out there.
It was built as a 3 burst capable battle rifle...That could 'accurately' take down a target up to 500yds.
If you look at the number of EBR's that are 3 burst, it's in the 80%'s...NSWDG stopped pushing for Crane to do the conversion when we started to see the end of OEF. Unfortunately, that's what you see on the civilian side - Over the next few years, there will be a "surprising" number of those select-fire trigger groups, available.
Anyway, that's what they do - They "accurately" take down a target at 500yds with a burst...Call it a day. You will NOT find a better rifle that can accomplish that goal. It's a PIG at 12-15lbs to compensate for the burst. The piston system aligns itself to practically no recoil - BOOM BOOM BOOM within 1s and 2-3MOA @500? Good game.
I've been behind the HK417 on more than a few occasions, had an M110 for a while...I settled on the Armalite Super SASS in 2009 or so. Love my SASS.
I'm not a fan of KAC and the SR-25. Quite personally, I think they're insanely overpriced...I'll stop now, If I don't I'll go on a 10 minute rant about KAC...There's been no new technology on the SR-25 in quite some time which is the the HK 417 decimated KAC in the 2019 trials...
The SR-25 cannot handle a burst. It wasn't designed to. The deployed guys that have the select fire groups, will tell you they never use it because it's shit. It'll hop all over the place. It was designed to be a semi-auto version of the M24 that could handle rapid engagements at up to 1000yds - Which is exactly what it does.
Each weapon has it's place.
One is a battle rifle that's PROVEN itself in Iraqi Freedom and Enduring Freedom. Fires 3 burst, accurately and capably eliminates targets within 500yds.
The other is an "enhanced" AR-10. That is capable of engaging targets out to 1000yds.
They serve 2 very different purposes once properly equipped.