To a bit more specific, with the 625 there are currently 2 different types of rifling in use. If you look at the web page for the 625PC you'll see that they specifically state is has "deep cut Broached rifling". As for the 625JM, mine was test fired 8-10-2011 and features the newer ECM rifling, so it's probably safe to assume that all of the current production of the 625JM will feature ECM rifling. Based on my experience with the ECM rifling I would not recomend using anything but jacketed ammunition in these barrels.
As for why, my model 620 features a tensioned barrel with ECM rifling and I tried it once with some cheap Blazer LRN because I wanted to test for reliable ignition function during a period when I was experimenting with lightening the DA trigger. Since CCI has a reputation for "hard" primers I felt that Blazer would serve to test for ignition reliability. Just 50 rounds of that nasty ammo cost me about 10 hours of barrel scrubbing and the leading was so severe I was concerned it could produce a squib with a full power 38 spl. In plain english the barrel was a total mess from forcing cone to muzzle.
Now on a positive note in regards to the newer ECM rifling, IMO the benefits are twofold.
One is the accuracy, IMO they are more accurate. However, that's simply an opinion. What I can state for a fact is that all 3 of my revolvers with ECM rifling produce accuracy that is only limited by my ability on that particular day. Today was another example of this, kept getting teased with 3 shot strings that spanned under 1.25 inch with my 625 but could not get one single cylinder under 3 inches including the flyers. Ended up with a 4 inch hole in the target at 25 yards resulting from 3 cylinders shot from a rest.
The second benefit is that they feature a much smoother surface finish than the older broached rifled barrels exhibit and I suspect that means they'll produce a bit more velocity when shooting jackted ammo. BTW, this is simply a hunch based on the surface finish. However, it happens I have an older 67-1 with a Barrel/Cylinder gap that is a dead match for that in my 620 and one day plan on purchasing a chronograph just to see if there is any difference between the two shooting jacketed ammunition.
As for the cost difference, the 625PC will run about 100 dollars more than the 625JM out the door. For my 625JM the total cost with taxes was 890 and change, so figure about a grand for the 625PC. IMO you'll also need to factor in the potential for new grips, I wasn't real impressed with the fit of the grip on the 625JM in my hand and the 625PC uses a similar profile with what I consider a gaudy color scheme.
You'll also need some tools for loading moon clips if you use the steel clips, they can be a real bugger to load by hand, especially that last round. Good news is I've now run 180 rounds downrange with my new 625JM without any cleaning and rounds loaded loose can be shaken free or snagged out with a fingernail. One huge advantage with shooting with clips is that you can load up a bunch at home, take the ammo to the range and do nothing but swap empties for loaded, then you bring the fired casings home still in the clips. This means you never lose a single casing unless you forget to pack a clip home. BTW, the American Eagle 45ACP boxes are sized perfectly to hold 8 loaded clips, so I would recomend purchasing some of this particular brand from time to time, most others will only hold 6 or 7 clips.
If you are interested in the 625JM you may want to look at my report on my latest revolver. Following is a link to that. I should also warn you that wheelguns can be addicting, I am quite certain the 625 won't be my last new revolver, it's only the most recent. Mine als shipped with a couple of issues, one which was easy for me to fix and one that will require warranty service. The good news is that S&W has a sterling silver reputation for customer service so I have no doubt it will get corrected.
http://smith-wessonforum.com/s-w-re...e-interested-625jm-updated-renge-results.html
. I had actually be comparing the 625 JM, the 325 TR, and the 625 PC. The 625 PC and an addition Plug purchase are now in my future. My thanks go to the OP foe starting this thread that lead to these answers.
