Help requested from someone with expert knowledge on coins struck on Type I Blanks (no rim)

As many of you know, I collect many types of cool errors, in particular, wrong planchet, double/multiple strikes, off-metal, wrong stock, broadstrikes, plating errors, off-centers, unstruck blanks and planchets, and coins struck on blanks (no rim).

I notice so many coins struck on rimless blanks often are either missing features or have weak strikes on parts of the coin. (Oftentimes, the missing/weak areas are always in the same places for certain denominations.)

My question is this: Is the reason they tend to have missing features/weak strikes in certain areas because not having the rim makes it slightly larger, and thus it sits in the collar slightly angled? And then because it doesn't lay perfectly flat, it can't be struck properly and directly head on to display all the features prominently? (Similar to if a rubber was stamped on an angle, part of the features would be strong and part would be missing or weak?)

 

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@Fred Weinberg
@mikediamond

I know nothing.. What's a blank?

 

A simplified explanation is metal flow.

Dies are basined, meaning they have a slight curvature with the centers of the obv and rev being slightly closer together when installed in the press. This helps push the metal up into the main devices. Metal also flows away from the center and into edge letters, numbers, and rims. The rims need a lot of metal to fill completely, and with the basined dies, it’s the area of dies that are farthest apart. The upset rim adds more metal to this area so there is enough to completely fill the rims. There just isn’t enough pressure and metal to flow into the rim on Type 1 blanks

I’m sure there are others who can add to some details or correct any errors in my explanation.

BTW: On a side note, ever notice that clashes always seem to be in the center of the coin? It's due to basining.