I worked as  a nurse in Emergency Rooms at different times in a 40 year career. Let us do some medical logic that we have on hand and add the studies on gun violence for decades on top of that. The results with those who commit suicide with a gun, shows that if a gun is handy the event happens more often, but if a potential suicide victim has to go and use another "method" they have more time to think about what they are doing and that time is valuable in making the decision not to end their lives. Same as for murders, the gun is handy to settle disputes more often than having to search out other means when one is angry. There are more murders by guns than by knives or baseball bats.   Research shows that people kill with guns because there is little time between the thought and the event. Having even a small buffer zone can prevent someone from killing someone else or killing themselves.
I have talked to many people who did not commit suicide and the reason they did not.