...A firearm, particularly one that is loaded or has ammunition in close proximity, is considered a dangerous instrumentality and therefore requires a higher degree of care in its use or handling. This concept is set out in the Restatement (Second) of Torts, which provides:
Care required. The care required is always reasonable care. This standard never varies, but the care which it is reasonable to require of the actor varies with the danger involved in his act, and is proportionate to it. The greater the danger, the greater the care which must be exercised.
As in all cases where the reasonable character of the actor's conduct is in question, its utility is to be weighed against the magnitude of the risk which it involves. [Citation omitted.] The amount of attention and caution required varies with the magnitude of the harm likely to be done if care is not exercised, and with the utility of the act. Therefore, if the act has little or no social value and is likely to cause any serious harm, it is reasonable to require close attention and caution. So too, if the act involves a risk of death or serious bodily harm, and particularly if it is capable of causing such results to a number of persons, the highest attention and caution are required even if the act has a very considerable utility. Thus those who deal with firearms ... are required to exercise the closest attention and the most careful precautions, not only in preparing for their use but in using them....
Restatement (Second) of Torts § 298 cmt. b (1965).
Accordingly, given the foreseeability of the risk involved in the improper and unsafe use and storage of a firearm; given the strong policy considerations favoring safe and prudent use and storage; and on the basis of the law as set forth in §§ 1-1-204, 27-1-701 and 28-1-201, MCA, our decisions in Limberhand, Maguire, Phillips, Mang and Busta and the above referred to standards of care set forth in Prosser and Keeton on Torts and in comment b to § 298 of the Restatement, we hold that, as a matter of law, the owner of a firearm has a duty to the general public to use and to store the firearm in a safe and prudent manner taking into consideration the type of firearm, whether it is loaded or unloaded, whether the ammunition is in close proximity or easily attainable, and the location and circumstances of its use and storage.
Because we conclude that Susanj owed a legal duty to the general public to store his firearm and ammunition in a manner consistent with this standard of care,...