I happened to be present during the initial (and final) test firing of a poorly thought out conversion of a 20ga. Stevens to 32Win Spec. Now here is a good place to state that STEVENS / SAVAGE guns are not suitable for ANYTHING other than the original chambering! Their single bolting system is argubly the weakest of any modern era doubles. That said, the gun wasn't put together too bad and the head space was (alledgedly) within spec. The one thing over looked was the non-bushed strikers! The large firing pins apearently projected too far and the first shot resulted in the right striker being blown out. Not to be defeated so easily - not to mention nothing left to lose - the string for "remote firing" was transfered to the rear trigger... this time the stock was blown completely off!!!!!!!! What's more, this was factory ammo not "proof loads!" JUST DON'T DO IT!

Now, as for the twenty bore's suitability, even this poor example of an action held tight. Additionally, twenties actually have higher chamber pressure than larger bores. There is the issue of wall thickness as well as the important factor of weight in a heavy recoiling rifle, but strength? I'm not convenced the twenty would be over burdened in reguard to low pressure rifle rounds... I wouldn't use one, but not because of strength.