Moving up to stronger recoil springs, and heaver buffers is either a solution to allow the rifle to run with heaver than standard ball ammo (ball being 55gr and 62gr) since the heaver ammo uses slower burning power which cause higher gas action pressures and such will bring the cycle back to normal (not over functioning instead),  Or the rifle has a problem with the gas port too large to start with, and such being used as a band aid to correct such.



So stating that you are using both a stronger recoil action spring, and a heaver buffer, are you shooting heaver ammo with slowing burning power, have a problem with the gas port being too large, or another problem you have not stated that is requiring such.



Simply, load a single round into a mag, insert and charge the round while leaving the empty mag in the well, and fire the round to confirm that the bolt is being locked via the bolt catch (catch in front of the bolt and not just catching the bottom of the carrier), hence rifle correctly stoking, and not the over sprung or over buffer massed.  If the bolt is not locking back, then start from scratch, hence standard recoil spring, and standard weight buffer, and start checking the gas system for blockages or leaks.




As for basic binding checks if the rifle is stroking correctly, but the bolt refused to lock up correctly,
Pull the bolt off the carrier and with the carrier and key, dry fit that into the upper receiver to not only check for key binding, but the gas tube aligned correctly with the carrier key.

As for light primer strikes if the bolt is locking up correctly (face of the carrier tight against the face of the barrel extension), confirm that the hammer spring was installed correctly.  The leg coils of the hammer spring should be coming from the bottom of the coils, and then up and seated on top of the trigger pin.



Lastly on the subject of problem rifles, make sure that the problem does is not from a suspect mag.  Cheap clone mags often are a problem with themselves, so always have a known working USGI for testing, so you are not chasing your tail looking at the  rifle, due to a questionable mag the source of the problem instead.

Always start with a single loaded round in a mag, and fire the round while leaving the empty mag in the well  to make sure that the bolt is locking back on the bolt catch (to confirm that the rifle is full stroking at cycle)..

This weeds out short stroking problem that either first need to be solved, or if the rifle is stroking correctly, then really, really, narrows down the solution to the specific of the problem that the rifle is having instead.

FYI, damage industries make two different length springs (telescoping and full length stocks), and are you sure that you have the correct length spring to begin with?


I still say test with a standard carbine spring (10.5") and standard 2.9g carbine buffer since you are running a telescoping stock to see if you have problems, then you can start swapping out after that.

Doubt that you currently have a 2.9 oz tungsten powder filled buffer, but you could make one by removing some of the powder to get it down to a 2.9oz.


The only thing I suggest is that you try the standard verses reduced powder buffer to see the difference between cycle times.  

With the reduced powder buffer, may end with not enough rearward stall time at end of back stroke to allow a questionable mag to recovering in time before the B/C moves back forward for the next round strip out of the mag.

The weights in the buffer creates a dead blow effect on both the back and forward end stops of the action cycle,

Hence dead blow effect stalls the buffer at the back of the stroke to give the mag more time to recover before the B/C starts to move forward again to strip the next round on the way to bolt lock up,

And in the case of full auto rigs, prevents the Carrier from bouncing back of the barrel extension at block lock up (resolves bolt bounce) to unlock lock the bolt/ carrier moved back and blocking the FP from full protrusion as the hammer is coming down on a full auto rig set on full auto firing the next round.  To understand this, hold the B/C in your hand, and look at the bolt of the bolt as you cam the bolt forward and back in the carrier.  Simply, until the bolt is in the lock position all the way back in the carrier, the bolt tail will not produce out the back of the carrier channel for the bolt, which prevents full protrusion on the firing pin out the front of the bolt.


As for if dead blow effect of the buffer is needed in a semi auto rifle, bolt bounce is not a problem a semi rig, so it came down the mag recovery time, and so long as the mag is able to keep up with the faster cycle, you can cleaning patch pack all the buffer weights in the buffer so they do not reciprocate (punch out the buffer roll pin, pull the buffer bumper and start packing in cleaning patch to the point that reinstalling the buffer bumper fully seated is a bitch to get in all the way to reinstall the roll pin.