Ok, MIM parts and locks have been discussed to death. I see a bigger problem with EDM barrels. I haven't heard anything good about them. People say the rifling is rounded off instead of sharp like a button-pulled or similarly machined barrel. How many S&W guns barrels are EDM nowadays? I'm glad I like older models, but I would accept MIM or locks but not EDM from what I've heard.

ECM, I think. Whatever the newer rifling profile, and however it's created, it shoots as well as anything S&W's ever done! I even shoot cast lead with no more (or maybe less) dramas than the old style. Fret over it all you want, I like it just as well. (Not that I shoot much past 100 yards with handguns anymore...)

No issues with ECM rifling here on all bullet types, my revolvers shoot great when you remove the idiot holding them.

I agree with all of the above. My 620 features an ECM barrel and with a handgun scope and lot's of practice I've managed to shoot 7/8 inch groups with it at 50 yards (or 150 feet). I suspect that it a pistol vice or in the hands of an exceptional shooter that sub 1/2 inch groups are possible.

Sounds like your 620 is already in the hands of an exceptional shooter.

Some of the top 1911 match grade barrel makers use ECM on their high end products.

There are two processes being confused here:

Electric Discharge Machining (EDM).

and

Electro Chemical Machining (ECM).

EDM is used on high end products and is expensive, but precise.

ECM is less costly and more suitable for mass production.

Here is a blurb on both processes:

Firearms History, Technology & Development: Rifling: Manufacturing: Electro Chemical Machining

ECM is a much more controllable process for these times where you can't count on the guy running the machine to constantly be checking, listening to and thinking about his process.

I hate the lock, despite now having one of the **** keys in my pocket, MIM makes me nervous but the ECM barrel doesn't really worry me. I'd rather have a forged 27 profile barrel made the old way but the barrel on my new 627 looks good so far. If it will stop raining I will put it to the test.

ECM it is. I've just been seeing a lot of complaints here about newer barrels. I think most comments leaned toward not being able to shoot cast bullets as well. It may be malarkey.