Hello & Welcome, Barb K!
In view of the poison sumac episode, I believe you must regard the guns as a real threat. (I hate to use the word "must," but here I believe it warranted.)
As a narcissist, your husband is probably feeding off your fear and humiliation and may want to prolong that situation. Nevertheless, he's shown a willingness to hurt you physically; if he thinks he's squeezed all the "narcissistic supply" out of you he can, he may not hesitate to dispose of you.
Please get the authorities involved and obtain expert legal counsel. "Better safe than sorry."