Suicide is indeed often an impulsive act, in which the urge must coincide with the means.

Stronger evidence for this claim:

Decrease in suicide rates after a change of policy reducing access to firearms in adolescents: a naturalistic epidemiological study.

The use of firearms is a common means of suicide. We examined the effect of a policy change in the Israeli Defense Forces reducing adolescents' access to firearms on rates of suicide. Following the policy change, suicide rates decreased significantly by 40%. Most of this decrease was due to decrease in suicide using firearms over the weekend. There were no significant changes in rates of suicide during weekdays. Decreasing access to firearms significantly decreases rates of suicide among adolescents. The results of this study illustrate the ability of a relatively simple change in policy to have a major impact on suicide rates.

Use of army weapons and private firearms for suicide and homicide in the region of Basel, Switzerland.

FINDINGS: Firearm suicides were clearly the most frequent means of suicide. They were also used in 30.0% of domestic homicides, although other means were used at similar rates. Firearms for suicide were mainly used by men, especially army weapons. These men were younger, professionally better qualified, and fewer had ever been treated in one of the local state psychiatric services.