S&W ECR rifling? Inquiring minds want to know

[Master Blaster]

I am curious as I'm sure a few others here on the forum, to learn more about the ECR rifling used on Newer S&W revolver barrels.

How is it done?
What are the advantages / disadvantages?
The depth and durability compared to the old cut and button rifled?
Does it stabilize some types of bullets better than others?
Is it used on all of the new revolvers?
When did S&W start using it?
Does it result in higher velocity and better accuracy?
Did it require changes to the formulation of the barrel steel?
Should certain cleaning solvents be used or avoided?

I'm hoping to hear from our new member 500swmag on this.

Thanks

 

[braindead0]

Sound to me like a cost-cutting measure for the most part.

At least that's my completely un-informed opinion at this time ;-)..

 

[Jim March]

Just from the descriptions, if the barrel interior is mirror-smooth, that's a wonderful thing for keeping fouling and leading under control plus making it easier to clean.

Might give you some velocity boost too. On a snubby firing 38+P, you need every bit of oomph you can get .

 

[Master Blaster]

Found some info on ECM

Electro-chemical Machining (ECM)

ECM removes material by utilizing the principles of electrolysis. The ECM tool (cathode) is positioned very close to the workpiece (anode) and a low voltage (less than 20 volts) high density DC current is passed between the two via an electrolyte (usually salt water). Material is removed from the workpiece and the flowing electrolyte solution washes the ions away. These ions help form metal hydroxides which are removed from the electrolyte solution by centrifugal separation and filtration. The ECM process can produce through-holes, cavities and trepanned shapes of virtually any geometry. The required geometry is produced using a tool that is carefully designed and manufactured to the basic shape and size of the machining operation required.

ECM Advantages

Machines materials otherwise unmachinable by conventional wear
Tough materials machine equally as quickly and efficiently as soft materials
Excellent surface finishes produced
Good tolerance, control and repeatability for complex shapes
Barber-Nichols has a unique capability to use ECM for manufacturing parts used on turbomachinery. The pictures below show some components that were machined using the ECM process

Complex Geometry Machining

A wide variety of geometries, which are difficult to machine using conventional methods, can be formed with high accuracy but at low cost using the ECM process. This process also allows for the creation of helical fluting (rifling) in boars of various sizes/lengths for medical and process systems applications.

For example, the photo depicts a work piece and the tool used to create it. On the left is the work piece--a helical lobed air motor rotor to power a thrust reverser for aircraft. On the right is the ECM tool used to remove material from the center of each of the 3 lobes throughout its length in a helical pattern. This operation is undertaken to reduce weight and inertia of the rotor. ECM is the only process that can perform this operation at a reasonable cost.

 

[GooseGestapo]

My first and only experience with the ECM rifling from S&W is with a mod337-Ti in .38spl.- a 3" bbl "Kit" gun. (I bought it direct from S&W as it was a factory reps demo gun) (I also have a '01 manufactured mod617 that is very accurate-don't know if it is an ECM bbl.)
It is the absolute smoothest barrel I've ever encountered. (I have a number of custom hunting rifles and match pistols to compare it to). It (the revolver) is also absolutely tack driving accurate. Cleaning the barrel is a breeze as leading is nearly non-existant and brushes out very easily.

However, I have heard of problems with/from other companies that use this procedure. A friend ordered a Nowlin barrel to install in a custom 1911 "Bullseye" gun. Built the gun up and fitted the barrel. Bench testing was impossible as gun sprayed bullets everywhere. It was later discovered that rifling was only .001" deep in barrel. Nowlin refused to make good on the barrel as it had already been "Altered". I had a PPC 1911 built with a Nowlin barrel that also would not shoot better than 6" at 25yds. The gunsmith ended up taking the gun back and later, Nowlin did make good on that barrel after they examined it.
He now will not use anything but a Kart or BarSto barrels now as they have taken back "bad" barrels and made good on them.

So, it depends on the Q-C as to whether it is a good method. And product is only as good as company behind it.

 

[mikey357]

...we visited S&W in Sprigfield in July, 1998...they were almost through with changing over from broached rifling to ECM rifling in their revolver barrels at that time...I remember talking with one of the ECM machine operators...he had an old-style rifling broach on his workbench...said it cost around $1200 to make--!!! He also told us that the ECM cathode would last MUCH longer than a broach, and at a lesser initial cost...he didn't have much info on potential accuracy differences between the two types of rifling, nor any info on wear differences...FWIW....mikey357

 

[Master Blaster]

Thats interesting GooseGestapo, The custom smith our club members use is George Madore, hes getting up there is years, his procedure before fitting any barrel:

George has a Mauser action and part of a stock with a clamp on it, on the front is a fixture to hold a .45 acp barrel he fires 5 rounds of his match ammo at 50 yards on our outdoor range, if the barrel does not do under 2", he sends it back, he only uses Kart or Barsto barrels.

If it does under 2" he fits it to the gun.

I really want to hear from 500SWMAG on this ECR thing, especially with respect to accuracy and durability.

Thanks

 

[500swmag]

Master Blaster,
I can't speak giving exact numbers as to accuracy, but I can say that our specs haven't changed. I mentioned this somewhere before but I had a 686+ in my desk for a couple of years that had over 10000rds thru it. I've been thinking about it and think that number is closer to 20000, but either way It shot close to the same as it did when I started. I could regularly get 2-3" @25yds with this gun only resting on the grip butt.
BC

 

[Master Blaster]

I'm curious to know which revolvers the ECR rifling is being used on? Is it every revolver S&W makes now or just some of the standard production?

The reason I ask is yesterday I was in my favorite local gunshop, and I looked at a new performance center .357 with a 3" ported barrel. It did not appear to have ECR rifling just the standard rifling.

I also handed a new titanium j frame, and it appeared to have conventional rifling in the barrel insert as well.

So what models is it used on, and which are still using the broach method?

Thanks

 

[500swmag]

tough one.... sometimes barrels go through the production line broached sometimes ECR'd. Demand plays a big part of this, sometimes to meet demand both the broaches and ECR machine are used. Currently all 22 caliber barrels are broach rifled. PC guns with slab sided barrels and other non production type barrels use broached rifling.
BC

 

[CZ-75]

So the PC does use ECR in some of their barrels?