New to this one, but I recently purchased a built gun with upper end components. 18" ss 223 wylde barrel, 1-8 twist. It is having some trouble cycling certain 5.56 rounds. Has anyone experienced this?

Need more info on your feeding problem, is it short stroking due to lack of gas? What type of gas block are you using? I wouldn't think the Wylde chamber would contribute to a feeding problem, I would guess mag or gas/buffer issue would be more likely.

Try a new mag first

What length gas system and buffer weight?

Don't see how a Wylde chamber would cause cycling issues.

That's the same barrel setup that I have on an Armalite M-15 and I have put at least 12 different types (manufacturers & weights) of factory loads through it with zero issues. Like others have said, I'd look elsewhere for the solution, like the gas block or mag.

Is it a rifle length gas system? because 18" + rifle gas is commonly undergassed.

A few options to fix: enlarge gas port, lower buffer weight, cut off a couple coils of the action spring, lighter hammer spring.

Sorry guys. FEEDING...not cycling. It only feeds the initial round about 80% in to the chamber. This is done with the charging handle pulled all the way back and then released.
Gun has not been fired by me. Supposedly will fire and feed 223 without issue. The 5.56 is giving it problems though.

So:

* lock back bolt
* insert loaded mag
* release bolt catch

are you seeing different behavior with 5.56 and .223 rounds? That absolutely should not happen.

Seeing different behavior within different brands of 5.56.
The 223 have never been a problem.
I switched brands of 556 and the issue fixed itself.