Quoted: Is it possible to cause a malfunction by having too much buffer spring weight (resistance)? Rifle is new with approximately 200-250 rounds through it.

Not if the problem is over function, such as a rifle with a 5.56 nato chamber running fine on Wolf ammo, but chocking on m-193 or 69gr+ ammo.

Just how many rounds threw the rifle, and at what period/round count are you re-lubing the rifle through the carrier exhaust ports?

Over function is when the gas port is too large, and the action unlocks too early (barrel pressure too high).

When the round hits peak barrel pressure, the barrel is upwards of 50K PSI of pressure, and the barrel has to bleed down pressure before unlock to allow the case pressure tensioned bond to the chamber walls to lower to the point that the case can be extracted cleanly.  The hotter/higher working pressure of the ammo, the higher the barrels working residual pressures at unlock.  In regards to heaver bullets, slower burning gunpowder is used to get the bullet to speeds, but slower burning powder has a longer burn, and the residual pressures in the barrel during unlock is greater as well.

What this all boils down to is the rifle (barrel) may be oversized ported to run with weaker ammo, but when the Hotter Nato or heaver bullets ammo using slower powders are used, the residual pressure in the barrel is much higher than the normal (weaker ammo) during unlock, and the spent case is more pressure bonded to the chamber sidewalls during extracting.  This causes the B/C to loose too much momentum/speed during the initial extraction prying the over pressurized spent case off the chamber walls, and the rifle acts as if there is not enough pressure to the system.

Bottom line is there specific  pressure envelope that the system will work within, and this is a balancing between the residual pressure of the barrel during unlock, and how the amount/timing (dwell) of barrel gas pressure to the B/C gas system allows the barrel to bleed off some of the unneeded pressure out the muzzle before bolt unlocks and extracts the spent case.

Instead of completely rewriting the one of the posted topics, you can just read it in its entirety since it does cover the topic quite well.

www.ar15.com/forums/topic.html?b=3&f=66&t=266108

P.S. with these items on the rig to make the rifle run,

I am running an all CMT 16" carbine. I have an O-Ring on the Extractor Spring, an H buffer, and a Wolff XTRA Power buffer spring.

The rifle is screaming Over function, since all of the above items are used to delay unlock in a rifle that is getting too much/to soon of gas pressure to the gas system, and prematurely unlocking the action.  As always, band-aids can be used to isolate/identity the problem, but in the end, you need to resolve the original problem, instead of relying of the band-aids and the side effects that come with them.  Simply, at the end of the day, the rifle should run with all factory installed stock parts, then you can venture into adding “Enhancement Parts” to tickle your fancy if you deem them needed.

Link fixed,

And pull at the add-ons and see if the rifle will run with stock parts.

The term you looking for is "short stroking", caused by lack of gas system pressure.
Over function is the opposite side of the equation, with too much pressure to the system.

Sounds like the extractor already has a Colt Black insert spring (read stronger than a standard spring), and the added O-ring just took the extractor tension over the top (too much case rim tension during the unlock slip of it around on the rim).

As for the H-buffer, and X-spring, time for a fire sale over in EE.

And the question that eveyone is thinking, why were these parts (O ring, H buffer, and X spring) added to the rifle in the first place?

Quoted: Parts were added just cause...they are supposed to make it "more" reliable.

When the bolt goes to unlock, the extractor slips around the spent case rim before the pull (since the case is still bound to the chamber walls).  

With too much tension on the extractor (or a bur), the extractor digs into the case rim, and you lose bolt reaward force as the extractor grabs the spent case and spins it in the chamber before the pull (read delay in unlock until the case will spin/slip in the chamber).

Quoted: Understood, but why would that result in a round being stripped off of the mag and jammed half way up the feedramps on the forward stroke?

It wouldn't, unless his hammer is catching the firing pin collar on a shorter then nornal stroke, and the bolt has just enough energy to just get the round out of the mag when it catches, then clears the FP collar (if you mean the bolt is behind the case rim).

If the bolt is on top of the case at the jam, and not behind the rim, then the bolt never cleared the back of the live round rim in the mag, and stripped the live round out of the mag from the middle of the case.