Calibrating LNL SS Classic to LNL AP presses

[diopter]

A few years ago UR posted this on Youtube:

Been thinking about doing it for some years now.

I recently measured the difference between my LNL AP (ser.# 12009)and LNL SS Classic(ser.# 25058).
I found that using a digital vernier was not very consistent and only one of my three fit into the the powder check die rod hole
Used a 45ACP case like Gavin did as the measuring surface on the AP shell plate and on the Classic shell holder.
I had to deburr the primer hole surface inside the case.
Then used a Starrett model 445 micrometer depth gauge with the 7 inch rod (4 inches stay in the micrometer barrel when at 0) through the powder check die.
This gave me a one inch measuring range from 3 to 4 inches from the depth gauge's cross piece
Consistent measure of 0.057" between my two presses. Afraid there is no possibility of a universal fit spacer. You have to measure your own presses.

AP press measured 3.536" from top of Powder check die to inside floor of brass case.
SS press measured 3.479" from top of Powder check die to inside floor of brass case.

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[PGW Steve]

I've got two Rockchuckers with the LnL bushings in them, and there is a difference between them. I've been meaning to get around to doing this, now it just makes me want to do it sooner. Like you, I think I'm only .04-.05" different, and parting off a thin shim isn't a precise operation, probably have to use the EDM.

 

[diopter]

And I haven't yet taken into consideration how much flex there is in the AP shell plate which will add a bit to the measurement.
Maybe I'll let the flex go as is since I don't see myself doing FL rifle 308W and over resizing on the AP anyway. Decisions decisions.

 

[diopter]

I've got two Rockchuckers with the LnL bushings in them, and there is a difference between them. I've been meaning to get around to doing this, now it just makes me want to do it sooner. Like you, I think I'm only .04-.05" different, and parting off a thin shim isn't a precise operation, probably have to use the EDM.

That's reminds me that I need to measure my Rockchucker with the LNL bushings as well.