Race tuning a 6" ported 686-5

[coolluke01]

I just sold my GP100 and have entered into the world of the S&W revolvers. I had that GP100 tuned up pretty nice. Very clean and light trigger pull.

Now, I want to make this smith trigger as nice. (ducks for cover) lol

Already this trigger is smoother than the GP, but the GP was much lighter.

I have been researching spring kits. I see Wolff makes one and brownells has a Jerry Miculek trigger. Which is better?

I chamfered the cylinders to 2/100's. Make a very big difference! How far do others chamfer them too?

I use this gun for steel action shooting and would like to get a good light but reliable trigger.

Please forgive the crotch shot. lol

 

[MrBorland]

I have been researching spring kits. I see Wolff makes one and brownells has a Jerry Miculek trigger. Which is better?

Can't help you here. I generally tune mine by gently re-arcing (read:bending) the stock mainspring (see pic), then installing a rebound spring to match.

I chamfered the cylinders to 2/100's. Make a very big difference! How far do others chamfer them too?

Can't help you with specific dimensions, but can caution you again over-zealous chamfering, of the ejector star or the cylinder section of the charge hole. Too much chamfer on either alone increases the likelihood of a case sliding under the ejector during ejection. Too much chamfer on both greatly increases this likelihood.

I use this gun for steel action shooting and would like to get a good light but reliable trigger.

How light, and how much reliability, and how much tuning do you need and/or are you willing to accept? If you're going to keep that hammer spur, but have a good action job done on it, you're likely looking at an 8-9lb DA trigger pull for good all-around reliability. Lightening the hammer by going DAO can buy you another pound or so. Handloading with Federal-only primers will buy you another pound or so. DAO guns with top-notch action jobs can get to 5-ish pounds, but you'll obviously need to handload with Federal primers.

Personally, depending on whether you bobbed the hammer, and/or how radically you bobbed it, I think a 7-8-9lb DA pull is the sweet spot, i.e. good balance of weight and all-around reliability. I've seen numerous reliability issues when one goes below this without the benefit of a really good action job, either from light strikes, or from short-stroking the trigger (which is really a technique issue). On top of that, most are limited by seeing what they need to see to make the shot, rather than being limited by trigger pull, so I've seen some pretty sloppy shooting from guys with über-tuned guns.

 

[coolluke01]

I would also like to know what year this gun is.

686-5
6" ported
pinned front sight
SN CDA59xx

 

[MrBorland]

Can't help you with specific dimensions, but can caution you again over-zealous chamfering, of the ejector star or the cylinder section of the charge hole. Too much chamfer on either alone increases the likelihood of a case sliding under the ejector during ejection. Too much chamfer on both greatly increases this likelihood.

Gulp...never mind.

 

[coolluke01]

lol. They look a lot deeper in the picture than they are.

The cylinder is .381
and my chamfer is .02 so edge to edge is .421
the rim of a 38 is .435, this leaves .014. It really is plenty to catch.

I'll post a few more pics later

 

[MrBorland]

It really is plenty to catch.

Maybe. Yours are static measurements. The trouble with lots of chamfer is that the cases can wobble at their last little bit of contact with the cylinder (especially so with shorter .38spl cases), so the real-world contact area between the rim and the ejector star can be considerably reduced.

 

[coolluke01]

That's true. I don't think I would recommend going anymore than .02 .

 

[BCRider]

I'm not sure who did the chamfering for you but I'd be concerned by the pretty solid appearance that the chamfering isn't axial to the chamber bores. The width of the chamfers is very inconsistent in this picture. It has the looks of work that was done with a counter sink tool in a hand drill instead of a proper piloted tool in a drill press or mill.

 

[coolluke01]

LOL. I did it. ;-)

It was done with a proper tool by hand with a pilot. They are properly aligned and are all within .002 of each other. I will give you the benefit of the doubt and blame the angle of the camera and not your eye.

 

[9mmepiphany]

Gulp...never mind.

That's what I'm thinking too...but I know I'm a bit bias from having seen a lot of cases slipping under stars

 

[MrBorland]

That's what I'm thinking too...but I know I'm a bit bias from having seen a lot of cases slipping under stars

Below's a link to a video featuring the current national SSR champ - he'd been having trouble with cases occasionally getting stuck under the star (from over-chamfering), and he had an episode here (stage starts at approx 3:00), and IIRC, again on the 3rd leg of this triple-header match. He cleared the case relatively quickly each time, but even that "relatively quickly" cost him about 20 seconds each time. Had another master-level SSR shooter been at the match, he surely would've lost.

http://www.youtube.com/watch?v=5LPRMfU90to

 

[Drail]

That cylinder and ejector are pretty much ruined.

 

[Sam1911]

Whoo boy. That's a whopping lot of chamfer! Just breaking the edge really did the trick for my competition wheelgun. I wouldn't be comfortable with that much material removed, especially from the star.

But the real test will be how it works. If you can run the gun at speed and it does not let cases slip under? Well, great! You dodged a bullet and beat long odds. If it does, you'll at least need a new star.

 

[MrBorland]

But the real test will be how it works. If you can run the gun at speed and it does not let cases slip under? Well, great! You dodged a bullet and beat long odds. If it does, you'll at least need a new star.

+1

If cases do slip, I'm thinking you could also have the cylinder machined to accept moonclips.

 

[ghitch75]

have it cut for moonclips that would save it.....

 

[coolluke01]

Man, I wasn't expecting this response. I've seen revolvers professionally done with at least this amount. But I do respect the opinion of those on here. I'll run it though it's paces and see how it goes. So far it ejects empty brass just fine.

Mr.Borland how much did you bend the mainspring? I suppose just a little at a time and test the results.

Anyone have any idea when this gun was made? Is there a place I can check this out at?

 

[scythefwd]

SW will tell you. Contact them with the SN

 

[BCRider]

It was done with a proper tool by hand with a pilot. They are properly aligned and are all within .002 of each other. I will give you the benefit of the doubt and blame the angle of the camera and not your eye.

Then perhaps your ejector star is inconsistent in thickness or bent.

I'm basing this on the relative widths of the chamfer on the star to the cylinder body for the chambers in that picture at 6 o'clock and the one at 10:30. The one at 6 o'clock has a much more narrow chamfer even compared to the chamfer on the cylinder. It's clearly even stepping down in width at the meeting line compared to a couple of the other chambers.

Anyhow at least you used the correct tool for the job.

 

[MrBorland]

Man, I wasn't expecting this response. I've seen revolvers professionally done with at least this amount. But I do respect the opinion of those on here. I'll run it though it's paces and see how it goes. So far it ejects empty brass just fine.

I have seen this much chamfering on a moonclipped gamer gun, where rogue cases are a non-issue. I agree with your plan, and with Sam's earlier advice - just run it. If it works fine, cool. Could be a non-issue.

BTW, if you're going to shoot .357mags through it, and plan on reloading the cases, keep a very close watch on the case wall near the base - deep chamfering can leave this area unsupported, so hot high-pressure loads can weaken the case there.

Mr.Borland how much did you bend the mainspring? I suppose just a little at a time and test the results.

Yep - Just a little at a time and test, install a lighter rebound spring & retest. Repeat if necessary. A trigger pull gauge is very helpful. I really can't tell you specifically how much bend I put in it. IIRC, the action on the 625 in the pic is down to 6-7lbs, with a 12lb return spring.

Anyone have any idea when this gun was made? Is there a place I can check this out at?

Very late 90s, very early 2000s. The -5's started in 1997, and were the last made before the internal lock, which was introduced in 2001 with the -6.

 

[coolluke01]

Thanks for all the help.

You guys had me second guessing myself, so I tested it more today. With spent rounds in the cylinder I pushed the ejector rod just about to the point where the casings left the cylinder. I pushed to the side trying to force each case rim away from the extractor star. I couldn't get them to slip under. It seems to be ok. I'll run it more to see for sure, but it looks like I'm in the clear. I had double, triple and quadruple checked my measurements before I did this though.

I can see what you are saying about the star chamfer. I have noticed that the cylinder doesn't swing out smoothy in two positions. It looks like the ejector rod tip that protrudes past the star has a steeper bevel on one side that the other. But it could be bent. I'll look closer at that.

Does anyone know what size punch I need to remove the pinned front sight?

 

[Drail]

It is a non standard size - you won't find one at the hardware store. I usually buy the smallest size they stock (1/16th) and chuck it in a drill press and grind it down a little. If you don't grind it enough it will stick in the pin hole (really tightly) Brownells probably has the correct size in their S&W tool section. Be sure to have the barrel firmly clamped in a solidly mounted vise and tap very carefully to drift the pin out. I have had cases slip under the extractor during matches on S&W guns (mostly with a M 57 .41 Mag.) with a very slight chamfer on the cylinder (and none on the extractor). If that happens you have blown that stage (and will use some extremely colorful language). This is usually caused by a rim dia. that is out of spec. more than the gun. I only chamfer very lightly on the chambers. Good luck.

 

[MrBorland]

I have noticed that the cylinder doesn't swing out smoothy in two positions. It looks like the ejector rod tip that protrudes past the star has a steeper bevel on one side that the other. But it could be bent. I'll look closer at that.

Check the other end of the ejector rod as well. If this end is bent, it can have the same effect. It can also affect the smoothness of the action.

 

[coolluke01]

It doesn't look like anything is bent, so I'm not quite sure what it could be.

I got the new spring kit and installed a 12lb trigger rebound spring. I learned that testing the trigger pull on a smith with the side plate off = lost springs. I guess the 13lb will have to do.

After installing the 13lb spring I loosened the hammer spring tension screw until I had 8.3lb in DA.
Why would you need to bend the hammer spring when you can adjust the tension screw? Does it provide a different/better feel by bending it?

I really like the trigger. I shot a 3 shot group that touched at 10 yards off hand in SA today and a 1" group in DA.

 

[Drail]

Testing the action with the sideplate off is a great way to bend or break the trigger and hammer studs. You really don't want to do that. The studs need to be supported on both ends when loaded by the action cycling. Reducing the mainspring tension also affects the physical shape of the mainspring. Go low enough and it will start "knuckling". The mainspring needs to be fully tensioned. If you want to go lighter buy a lighter spring. You really need to get the Kuhnhausen manual if you're going to mess around inside a S&W.

 

[coolluke01]

Thanks for the tip on the manual. I have one coming.