Who would think to call you a wimp?
If we were discussing this over cigars, between while standing out on the range comparing loads and controllability during drills, I'd probably suggest considering carrying all +P loads.
If you carry a speedloader/strip (or two), and think about the possibility of actually having to reload, why subject yourself to the sudden muzzle blast and wrist-stressing torque of that last Magnum round? If it might (I stress might) throw you off your stride in getting the snub emptied and loaded, there might be a questionable "benefit" to having that 5th round being a Magnum. (It might be an attention-getter, though, letting you know you've run the tank dry.
)Personally, I rather like being able to have the same felt recoil and expected controllability for the entire cylinder load.
Yes, I'm "giving up" a bit of added velocity by not using Magnum rounds in my pair of M&P 340's (which are even heavier and more controllable than your 340PD), but I'd rather be able to hammer out up to all 5 rounds as rapidly as possible.
No biggie, though. If you can put 2-5 fast and accurate rounds on your intended threat target, you're still likely to be head and shoulders above those handgun shooters who think that only a hi-cap ammo reserve is important.
