According to some Glock folk in this Thread, the semi-auto Glocks primarily fail to function because of bad or faulty ammo. Which was, and is, my point on the primary difference in reliability between "semi-auto anythings" versus revolvers, pump actions, or bolt actions. Semi-autos are entirely dependent on their ammo for proper function. The firing of the ammo cycles the semi-auto action, whether it be semi-auto pistol, shotgun, or rifle. The firing of the ammo is what causes the semi-autos to function as semi-autos. Bad ammo or poorly matched ammo = no semi-auto function.
Proper feeding from semi-auto pistols can also limit the shape of the nose of the bullet for reliable feed from the mag, up the load ramp, into the pistol chamber. I prefer wide flat-nosed revolver bullets for bear defense. So that's another potential compromise with a semi-auto pistol... for me. I can load and fire any nose-shaped bullet, or power-level ammo, in my revolvers.
A defective sidearm or long arm is an entirely different subject matter. Wise folk will thoroughly field proof their pistol/revolver or long arm of choice with their bear defense ammo to ensure reliable function, prior to carrying and relying on their firearm in the field. Non-defective revolvers, pump actions or bolt action long arms? Just about any ammo should function properly/reliably in a sound weapon. ESPECIALLY true, in comparison to any semi-auto firearm. Nevertheless, the wise move is to make good and certain the bear defense bullets aren't jumping their crimp in heavy recoiling revolvers, and that firearms are feeding and functioning with your selected bear defense bullets and ammo, whether factory ammo or hand loads.