I'm not sure i would agree that the post needs to be pulled, but it does bear careful thought. that's a 1" piece of rebar firing .22LR: a small diameter low pressure cartridge if there ever was one. You certainly wouldn't want to do that with higher pressure cartridges. The minimum yield strength of rebar in the US is 60,000 PSI, and the fact that the chamber portion is encircled with the high grade steel of that Yost action is even more of a safety factor.
Let's not get carried away with concern, eh?