STOP! Wait, hold on, relax.
You have two tungsten weights coming to you. You have two tungsten weights in that buffer that you have right now - none of these will go to waste.
Buy this buffer from DSG Arms. It's a 2.500" buffer for $22. It's 3.8oz, but it gets its weight from a stainless steel body (not aluminum body), with two steel weights inside. You spend $22, take it apart, take out it's steel weights, replace with the tungsten that you have, and you've made your buffer that you need for way cheaper...
https://dsgarms.com/lower-receiver-parts-dsg-4201-0021
Combine that buffer ^^^ with a Sprinco Orange spring, and you're set for your recoil system - done. It'll work like a champ, and I can tell you that what I'm describing is running in my .260 Rem gun right now. Buffer weight comes up to 5.15oz with that combination, and that's close enough to 5.4oz, and works WAY mo' bettah than a 3.8oz buffer and questionable recoil spring.