Cabela's headstamped cartridges wanted

Wanted: Cabela’s headstamped cartridges in any caliber!!

I have a 600 NE but know that there are other calibers. I heard a story that these may have been produced by Bertram and only used for store promotions at store openings or produced to encourage Cabela’s to handle Bertram products. Please share other information including calibers produced.

Since Cabela’s is a Nebraska family owned business, it only makes sense to assemble a Cabela’s headstamp collection in Nebraska.
Gary Muckel