comparing Smith rifling- new vs old

[castalott]

I've always thought the new Smith rifling system was a bit odd... To these old eyes the grooves are not deep and the lands are not square and sharp. I got a chance to look at a Model 27....wow... It has got real rifling in it!

Anyone else think this or am I out to lunch?

[Preacher Jim]

You are not out to lunch in my opinion

[tazman]

I haven't really looked since I only have one new S&W(a 686+). It shoots well with cast so I didn't even think about it.
I had a problem with a Taurus PT92 that had shallow rifling that wouldn't grip the boolits well enough to stabilize them for me. I swapped the barrel out for a Beretta 92 barrel and never had a problem since.

[osteodoc08]

The new ECM process they use is interesting in how it’s done. Definitely not the traditional cut rifling.

[rintinglen]

My experience with the "new" ECM process has been poor. My S&W M-69 leads terribly, despite correct fit and good lube. I am currently working on fire lapping, but that bore was horrible. I will be looking very closely at any future S&W purchases that I contemplate.

[castalott]

rintinglen... I have a friend who started collecting the model 69...he loves the small frame in 44....BUT he had leading issues like you. He had 3 of them at one time... None shot cast well at the start. After a lot of abrasives in the bore, one now shoots pretty good....I think it still leads just a little.... One (hopeless) was traded in on a 69 2.75 model ... It has been the best one out of the box but still could be better...

We have spent the better part of 2 months working on these... cutting the cylinder mouths uniform and fixing the muzzles...reminds me...look close at the muzzle. All 3 of the 4 inch guns, the muzzle was button rifled but not recrowned. At the end of each groove you could see a bit of metal sticking out past the muzzle.

Anyway, if you want to know more...ask

Dale

[frank505]

I firelapped ten shots in my model 69. It doesn't lead at all now. Nor do I clean the barrel, there is nothing to clean out. Handiest six-gun I think.

[castalott]

frank505... I would like to know more about this firelapping.... Thanks, Dale

[rintinglen]

I have 40 shots with 320 grit material through mine, plus at least 80 passes with a hand lap. It is better, but still not good. 40 shots still leave a healthy layer of lead, starting at the forcing cone and going forward. lately I have been shooting other guns and have not had time to get back to the M-69.

As delivered, the throats were <.429, but Doug Guy took care of that for me. Here's the before photo. Those are Hornady .430 FTX bullets. note that they stop on the ogive. Now all five chambers are as nearly identical as I can measure at .4325. Doug Guy is a master and I heartily recommend his work.

[Dale53]

I have both old and newer Smiths. I am currently shooting my Model 520 .38/.357 ("L" frame with target sights, 4" composite barrel and titanium cylinder). It is scary accurate and I shoot it well. I have never fired anything in it but my home cast bullets. My 625-8 JM Special is a .45 ACP/.45 Auto Rim and again, it is scary accurate. Again, nothing but my home cast bullets.

When I say scary accurate, well under 1" at 25 yards off a rest with a variety of loads. I haven't cleaned the barrels of these revolvers for several thousand shots. I just brush out the cylinder with a nylon chamber brush while hot, and wipe off the outside. NO leading and the barrel is always conditioned.

FWIW
Dale53