Sasquatch Hunter
Amateur
What ammo? Why? What barrel length and twist rate?
Federal Fusion is a hunting round not a specified up and prepared defensive load. I would be wary of cross purposing ammunition without a solid backstop of testing or data.
The FBI is different than the TBBC, it is closer to the Mk318 round (the internal geometry looks similar but there are difference in how the jacket and slug are bonded, as well as QC difference)
And yes I know you are talking about the Gold Dot round versus federal fusion.
If they are so similar then why is fusion not listed as a substitute for gold dot, with any major agency? Why does the manufacturer not list it as a substitute? Do you have testing data to back up your assertions?
Bottom line: Use defensive ammunition for defense and hunting ammunition for hunting, $0.03 (or whatever the cost difference is) a round isn’t worth it because that extra cost buys you reams of data and support.