Thanks,  Parashooter. You use the same bushings for large pistol and large rifle in the priming tools so I was sure they were close on the OD. As mentioned they are not designed for the same pressure so that is one issue.

Now knowing the 2 types of primers are so close and there is a slight overlap in tolerances I will never have the 2 types out on the bench at the same time to avoid any mix ups.

If the particular brand or lot of pistol primer is too short, that could lead to a hang fire. Opening the bolt 20 seconds later when it goes off would be catastrophic. 
Another thing not mentioned is old GI brass may have had corrosive or mercuric primers. Brass that is cleaned right after firing may prevent corrosive damage. If its initial firing was done 50 years ago and put away dirty, who knows what damage was done.

All that said I have used 40s GI 30/06 brass for really reduced loads and not had issues with only neck sizing. That brass was used first by my father so he may have cleaned after the initial firing.

The $5.00 dollar brass is not really a bad deal for putting it in a display case.