Defiance classic issue

[MagnumManiac]

Returning the action for inspection. Swipes continued all the way down to 30.5 grains. Something definitely not right

I would be inspecting how stiff the plunger ejector spring is in the bolt first.
It could be your brass too.
I had a wildcat based on the 22BR that would get swipes with every charge, took everything apart several times to finally discover there was drilling swarf in the ejector hole stopping the ejector bottoming out as it should.

Cheers.

 

[mudflap621]

I have ~15 defiance actions…I think they are great at the price I paid. However, they are known to have a bur or rough edge around the plunger hole

This is good bet. If had a few LP do the same thing so it's become one of the first things I check.