Just bought a new upper and am noticing a loud "Twang" sound in both semi and auto and both suppressed and unsuppressed. I have not noticed this sound when I shot other uppers on it.

Im sure the sound is coming from the spring, and the sound isnt annoying.

Im just curious why its making the noise and worried it might be making that noise because the spring is being to compressed or the buffer is striking the back if the buffer tube. Over time would this have potential to damager a lower? Possibly putting extra stress on the lower receiver rear hoop causing it to crack?

It doesn't really seam over gassed, it wasn't excessively dirt or throwing gas in my face while shooting. But maybe try and adjustable black and see if it goes away or am I just being paranoid?

Lower:
Oly Arms RR
H1 Buffer
Mil Spec Buffer Tube
Tubb's CS Flat Buffer Spring

Upper:
PSA 10.5" Upper
Anderson Charging Handle
BCM M16 BCG
Gemtech GMT-556LE/A2 Flash Hider

Thanks!

Embrace the twang - it just is.

If you want to get rid of it, you can try lightly greasing the spring and tube, or switching to a coated or flat wire spring.

It is not indicative of wear, nor is it harmful, it's just a harmonic causing the spring to vibrate. I'd say many, if not most, of my AR-type rifles have some degree of twang, and its absence is an audible indicator of lockback on an empty mag.

Im actually using a flat wire spring, which is why I was surprised to hear the twang sound on this upper.

I've only noticed the "Twang" on Colt 20" H-Bar uppers.
Other mfg. 20" don't sing for me, "SPROING"!

JP silent captured system will eliminate that twang.  Get the H model for more versatility.

*Shrugs* the sound doesn't bother me, just wanted to make sure it wouldn't cause damage