ritmaine,
I wouldn't think it would be dangerous, over the long haul. Since you didn't mention cases spliting, I wouldn't think gas cutting in the chamber would be a problem. There are more than one version of improved Hornets,some of which require fireforming in two stages,due to excessive case loss. Since you didn't mention it,I suggest you save all your fired cases. If you do this and do find someone to load K Hornet for you;you will be money ahead by supplying fireformed cases for your rifle. This would cut out one step he would have to perform and you wouldn't have to let him have your rifle to be sure the cases fit.There are custom handloaders all over, your local gunsmith should be able to help you find one. Good luck.
Mike