It has been a while since I have done a 20in upper. I got a good deal on a barrel, so I decided to build a clone-esq M16A4 from my infantry days. Because of this I am going to run a rifle buffer system/stock. Also I currently have a FSB on the upper. My question comes though about changing out some SS weights in the buffer for some tungsten I currently have.

I have run this 20in, rifle gas, FSB upper suppressed on my SBR lower that has a Vltor A5H4 (6.8oz). The results this upper suppressed and with the A5H4 were very positive. As I build a new lower for this upper, I am debating replacing a few SS weights with tungsten to bring it closer to the A5H4 buffer. Would this work, or would the extra length of the rifle buffer system change the characteristics and mean the A5H4 weight would be too heavy? This upper will be primarily shot suppressed

Also does a rifle buffer system offer any benefit over an A5 other than the adjustable stock (I don’t care about the twang noise). I have heard that the spring in the back of the A5 buffers may offer some benefit. If the A5 is superior in tangible ways to the rifle system when shooting suppressed , then maybe I would consider a USMC M16A5 concept.