I’ve been quite happy with my V4 & never tested the the tamp pressure… until now.
With the 25lb spring fitted I’m getting a pretty consistent 28lb until just before the handle bottoms out on the flange.
The instructions actually say you’re supposed the bottom out the handle when tamping to get consistent pressure, which contradicts what Normcore were telling you
How hard do l press?
A: Press down until the handle bottoms out against the base. The calibrated spring will ensure consistent pressure, The pressure used to tamp doesn’t need to be aggressive, just consistent, Don’t look for something as heavy as possible; the most important thing is using something comfortable.
This holds true as there’s a ramp up from when resistance is first felt as you continue to push, which it’s probably due to the spring rate not being linear as it compresses, but as I always bottom out the handle, which although not the claimed arbitrary 25lb, it’s good enough for me.
The difference between real world tamping & tamping on a scale is that in the real world once the handle bottoms out you’re not exerting any additional force on the coffee puck, however on a scale, once you bottom out you’re pushing on the basket itself so that will register a much higher force on the scale. But from your description & vid it doesn’t look like you’re going that far. (Edit: I was beaten with this comment while I was one finger typing)
One thing that would skew this is if the tamper was too large for the basket, where the tamper ends up pushing on the inside wall of the basket rather than the puck but it seems like with the VST/dose you’re using it shouldn’t do this as I generally use around 15-16g in a VST 18g with a 58.5mm V4 & never had that even with a high density bean.
Seems like very good customer service from Normcore though