a number of us have shot all kinds of ammo
in our M&P340s--much of it reloads built around two particular parameters:
1. Ammo that replicates the "Gold Dot Short Barrel" ammo with 135-gr. JHPs--a 38+P load running at 850+ fps, or a 357 Magnum load running at just under 1000 fps.
2. Ammo that replicates the nominal "FBI load"--a 38+P load with a 158-gr. LSWC-HP running above 800 fps.
3. We've also begun working on loads with the lighter-weight bullets, but AFAIK, we have no well-tested (re)loading data for the 110-125-gr. bullet range.
When I started shooting my 340, I used the FC 38 Special standard-pressure 110-gr. round--it was all I could tolerate at the time. As my hand became more conditioned, I moved on up to 'bigger rounds.' My current favorite reload is a 357 build running a 158LSWC at about 900 fps--which is a round not available in factory ammo, AFAIK.
Based on these experiences, personally I do NOT care for the lighter-weight-bullet loads--yes, they do have less recoil, but the "suddenness" of the recoil is more unpleasant to me than the "fuller push" of the slower, heavier-bullet rounds. The point is this: Competent performance out of these 2" lightweights depends on many subjective factors; be sure to consider other factors besides bullet weight.
FWIW, good basic performance criteria for shooting these guns are based on Old Fuffs "quad five" drill.
1. Five yards
2. five inch group
3. five shots
4. five seconds.
Select an ammo that will (eventually) allow you to do this. As an aside, at the cost of PD ammo today--perhaps $1.20 per round, if you can even find it, I understand--you might want to consider reloading, but that's another issue.
Marvin Knox: I really enjoy my 305 CTs on my 3" 60--it would be my bedside gun were it not for the five shot capacity. However, two years after purchase, the laser dimmed--so CT will have to send out another set, I guess.
Baxtereyes: I concur with your description of the M&P 340 trigger pull. It may make you feel better to know that, sampling issues aside, it is better than the aluminum-framed / cheaper lightweights. After about 2000 rounds through mine, it has cleaned up quite a bit. And, after nominally 18,000 rounds through my 640, the trigger is a dream come true. Both of these guns, BTW, had an iniital 'smoothing-only' action job done by my gunsmith. Finally, the 360 I added last fall has had the best "factory" trigger in a lightweight I've shot.
Jim H.
