Are you sure the Remingtons you used were Kleanbores... not the Remington STS's?

It's alsopossible that a mixup occured at the packaging plant where both areboxed & your Kleanbore box contained STSs by mistake.

There's a noticeable difference between the remnants of both primers. If the remnants were the same for both, then what you shot was not the Kleanbores.