The best I can explain is the "trigger" of the primer needs to sort of swing in from just left of the primer arm in the ram. Only talking a fraction of an inch between go and no go.

Tighten the nut holding the whole thing just enough that it will move with the wrench and move it just a bit until the trigger lines up.

Try it without primers to be sure it clicks on the primer arm.

It's easier done than explained.

Round bushing(spacer) black plastic primer unit, silver egg shaped washer (fits in the groove of plastic), bolt through to hold it together. Sounds like you have it installed correctly.

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