Aye, these also. Must be some minor differences in construction between manufacturers of these. My spring was never gold plated and my pos contact inside the batt tube isnt recessed. Its a flat round steel plate with a silicone bushing under it.
And sand the gold off the top of the spring while you're at it; where the spring contacts the battery.
I wanted to sand the battery pos contact point and the 510 pos contact point, but couldn't. They're recessed and I'm using a nail file. Even so, I put a volt meter to the 510 hot and the top of the switch (gold plated), and got exactly the same voltage as touching the battery ends directly. There must be some loss, but it's not discernible on my little multimeter.