NCyst:
If you are carrying OWB at all, why not keep the M65 for that application? The additional weight of a 3-4” all SS M65 is a huge aid to controllability with heavy .357 loads. Moreover, to wear out an issue that’s probably been posted here quite a bit, in a 1.9” barrel, the performance difference between the +P .38 and full-house .357 is not that great. The 340 is cool and super-light, though, so I can’t say I don’t appreciate the emotional side.
Again, I am a very big believer that training with pocket-carried self defense firearms demands a “shoot it like you’ll be using it” focus, mainly because it’s such a challenge to execute that effective FIRST SHOT from concealment. But all of us must maintain our basic sight alignment and trigger control skills. I still shoot all my defensive weapons in a stand-on-your-hind-legs-like-a-man, deliberative fashion at the range just for skills verification. All shooting is done at least at an NRA Rapid-Fire pace (5 shots/10 seconds) dictated by their likely use “in anger”.
Although I am certainly not an instructor and I don’t pretend to be one, I have given a number of friends and acquaintances some pointers in safe range practices and basic handgun handling and shooting. The first target is typical for me and achievable by any reasonably coordinated person. It is what I have told my “students” they should generally strive to achieve with their carry load before they step into more serious practical training.
It was fired from the 442 with some old +P Hydra Shocks. As you can see, I used a reversed B2 target. I tell people that they won’t have a nice orange bull or a fat guy silhouette with rings when the SHTF, and shooting from low ready at a blank sheet is a good test of how your eye will naturally find a CoM. Anyhow, if you can’t read the tiny writing, this was at 10 Meters, starting from low ready with a Speed Strip reload, 28 seconds end-to-end. (Yes, the 442 can shoot better. Stacking the trigger -- yes, I do it for recreational shooting -- I can shrink this group by half. Stoke the little fella with my 148Gr WC handloads, and I can carve off some more. But that’s just for showing off.) My normal Rem 158gr +P is about the same ferocity, and groups are similar.
From here I apply a rule that was espoused by a retired Houston Constable: Take the worst group you shoot in rapid fire on any given day. Now double the maximum spread of your hits. That’s the BEST you’ll do in a gunfight at that range -- probably worse. When you look at this target, you can see that I am at my limit for effective use of a lightweight J Frame with .38 +P.
Now, switch to the 65, and here is the result:
I didn’t have Speed Loaders with me so it’s only 5 shots and it’s fired NRA Rapid Fire pace. (I have no idea what I was thinking when I wrote “H-S” on the target; it should read HP. Also it's clearly NOT my M64. I think the noisy range distracted me.) You can see I tend to walk my shots to the left in rapid fire with a high-recoiling load. Plus I cheated by having an aiming bull. But it's a pretty typical result and it shows how much the extra weight “tames the beast”, and the additional inch+ of barrel really helps reduce error at impact. I am dead confident in the 65 at ranges beyond arms length with the hottest loads I can purchase. Fired SA, you can drill them into one big hole at that range.
I have actually fired the 65 “in anger”, successfully stopping a large feral dog that was determined to take charge at our campground. The range was less than 25 feet but both shots (the old Fed .357 125gr HP made famous by Marshall, rightly or not) went exactly where they were aimed in a very frantic situation. I’m sure the J Frame would not have served as well with the same load.
tl/dr: Although you didn't ask my opinion, I think the 65 is about the minimum .357 piece for me, and I shoot it better than the 442.