686 SSR Forcing Cone Issue

[badabing]

I traded an old 686-6 on a brand new 686SSR just over a year ago and was initially very happy with my purchase. Perfect carry up on all six, well finished, reasonable trigger, just an all-round nice looking revolver. Unfortunately that's where the frustration started, I just can't get this thing to group despite tinkering with loads for a year now and it leads up like nothing I've ever owned before. Not sure when the factory started threading forcing cones but this is mine in the pictures below and I think it may be the root of my problems? I also get a lead build up in the crown recess, I can't see any damage to the crown and I'm not sure if this is just a result of the forcing cone problem? The other beef I have with this gun is the bead blasted finish, it must somehow retain moisture or sweat because I get corrosion on this gun unless it is kept spotless again unlike any other stainless gun I've owned.

I am in Australia so returning to the mother ship is not an option, not sure what sort of reception I would get from the local distributor after a year so after weeks of reading, decided to order the Brownells 11 degree chamfering kit, the 11 degree brass lap and Power Custom brass muzzle crowning lap.

The question I have which I have not found an answer for is the angle I should use to break the edge on the re-cut forcing cone, 82 and 90 degrees seem to be the most common with some saying to leave it sharp so I'd be interested to hear what people think. I'm also thinking I might just do the forcing cone first and shoot it a while to see if the crown issue resolves itself. Also keen to hear from others that have re-cut forcing cones with their experiences good and bad since I figure I'll only get one shot at getting it right.
Thanks

 

[shovelwrench]

SEND IT BACK!!!!!!

That forcing cone is UGLY, I'm sure S&W will make it right.....

(edit)


HA, just read the rest.....

It really shouldn't matter, your diameter on the forcing cone corner/entry/edge should be larger then your throat diameter. Meaning, the bullet should not touch it anyway assuming timing is on.

If it were me and I felt i had to do it, less angle is better.

 

[bountyhunter]

Not sure when the factory started threading forcing cones

I have never heard of such a thing. I wonder if somebody used some kind of cleaning tool to remove lead that tore up the cone. At any rate, that is really messed up.

That crown looks NOTHING like the one on my PC 627, it looks like somebody over cut it.

Anyway, that barrel doesn't look right at either end.

 

[armorer951]

These are tool marks.....send it back

 

[Toblerra]

The recessed crown is supposed to be deeper on that model, I wouldn't worry about it too much. The forcing cone is a different story. I have read of this being an issue. I would start with less of an angle, you can always take off more if necessary. I would also polish the inside of the forcing cone, with a dremel and a mini buffing wheel with some compound to smooth it out. Concerning the bead blasted finish, I would do the same thing I did with my Stainless Colt .45, I broke it down completely bead blasted with a fine grit glass bead then buffed it out with mothers mag polishing compound. You can bring it to a mirror finish with that stuff if you want to. Just some ideas.

 

[scooter123]

What you are seeing at the crown is probably just gas residue, I have a 620 with a similar recessed crown and it looks the same after a couple of boxes have been shto with it. On mine those deposits wipe off easily with a cotton swab soaked in solvent.

The forcing cone on the other hand is a Train Wreck, a really spectacular Train Wreck. I know it probably will be rather expensive but I think that you should call S&W in the USA and talk to them about this problem. I would expect that they have some type of repair facility linked to the distributor for S&W in Australia and that facility should be able to do a warranty repair on your revolver.

As for re-cutting it yourself, with the barrel installed on the frame using a Pull type cutter you are looking at a lot of hours re-cutting that forcing cone. Because you won't be able to apply nearly as much pressure as would be possible doing this job in a Lathe. BTW, you want to duplicate the factory angle as closely as possible, because any deviation will mean that you'll have an area that isn't cut at the same time as the "highest" spot, so your cutting time will be extended. I can also tell you that the Chromium in Stainless Steels chews up cutting tools at a rate you have to see first hand to believe. Use lots of cutting oil and have at least 3 cutters on hand for when the cutters get dull.

Finally, I could see a really clear look at the rifling in your barrel but what I could see leads me to believe that you have the Electro Chemically Machined rifling. If so you won't have any sharp corners in the lands and grooves, they will be blended with a radius at each "edge". I've seen this type of rifling described as Overlapped and Shot Out and to someone only used to Ballard rifling this would seem an accurate description. However, in many ways it imitates the polygonal rifling featured in Glock and some other brands of handguns. Based on my experience with the ECM barrel in my model 620 the one time I used Lead RN bullets in it the leading was so bad that it took about 14 hours of scrubbing to get the barrel lead free. I've seen some claims that with the correct lube you can shoot lead in an ECM barrel but cannot tell you what that lube is. On my part I only shoot copper plated or jacketed bullets in my ECM barrels and I don't have problems with leading. If you've been using lead in your SSR and it does have an ECM barrel you may want to re-think your choice of bullets.

PS; the model 620 was a rather special 357 Magnum L frame that was basically a 4 inch 686 Plus with a Tensioned 2 piece barrel. The accuracy benefit of that tensioned barrel really needs to be seen first hand to actually believe it but IMO the model 620 is truly a 1 MOA handgun. Point is, there is NOTHING wrong with the ECM rifling except for that tendency to lead with improperly lubed soft lead bullets.

 

[badabing]

Thank you all for the advice and comments.
Well it has taken me most of the day but for better or worse this is my repair. As you can see some of the deeper gouges of the original S&W forcing cone close to the rifling are still there. It really looks like it was cut with no pilot and the cutter was just chattering around in there. In order to get the deeper marks out I would have to open the mouth of the forcing cone beyond the max specification which would result in a loss in velocity so decide to stop at this point.
The 11 degree Brownells cutter is an aggressive piece of kit. It is impossible to cut without leaving heavy tool marks regardless of how much cutting oil and care you use. It would be very easy to go too far with this cutter, it is extremely sharp. The hero of the day was the 11 degree brass lap which left what I think is quite a good finish and certainly an improvement on what was there before imho.
The proof will be in the shooting which will happen next weekend. Worst that can happen is that it shoots and leads up as bad or worse than it did before so no real loss, before I started I accepted there may be a custom barrel in my future.

 

[Nick B]

Night and day difference . Did you also get the gage to check your work ?

 

[scooter123]

That forcing cone looks better that the forcing cone in any of my S&W revolvers, so I would classify that as a Grade A repair. It also provides a clearer look at the rifling in your barrel and that appears to be the traditional Ballard type rifling, so I would expect that your leading issues will be history provided you aren't pushing a softer alloy too fast.

 

[badabing]

Thanks scooter123 here's hoping that's the way it plays out. I'm using hard cast and they are not driven terribly hard so hoping all will be good. Full loads and jacketed ammo are not allowed where I shoot. Certainly has been good learning experience.

NickB, No I didn't buy the gauge but in my research I found the max recommended forcing cone opening size so just used calipers until I got there. To get the original gouge marks out that are still there in a couple of spots near the rifling (you can see one in the photo above that also appears in the first photo of the op) the forcing cone opening would be way oversize.

 

[BLUEDOT37]

badabing, I had the same issue with my 686-6 Talo, 5" bbl. Hopefully your final results will be better than mine.

I too bought Brownells complete kit & cut/polished mine much like yours but it still leaded just past the forcing cone. I tried every conceivable combination & many different powders but finally gave up, having similar troubles in other guns. I used up all my cast lead bullets & switched to coated, plated, or jacketed bullets instead.

As far as the forcing cones opening being too wide (.020" over bullet diameter, IIRC?), I've checked a few of mine & from the factory they were too wide to start.

Let us know if it helped you though.

.

 

[badabing]

Bluedot37, you jogged my memory, there was one more thing I wanted to mention. I noticed when sliding the brass pilot in from the muzzle I found there was a definite constriction at the barrel threads, which sounds like where yours was still leading. I guess I'll have to cross that bridge when I come to it. Jacketed is out of the question for me but I will have to ask about their policy on plated. In the mean time I've got my eyes open for a good second hand 686-4 or 66-?, maybe even a Python if my wallet can stretch that far.
Yes, .020" over bullet dia is what I was working to. My understanding is going over (within reason) is not the end of the world but you will lose some velocity.
Must say I do regret selling my old 686 now, while the SSR looks the part the workmanship is just not there.

p.s If anyone from Grycol is reading this and wants to make this barrel right for me please get in touch!!

 

[BLUEDOT37]

Bluedot37, you jogged my memory, there was one more thing I wanted to mention. I noticed when sliding the brass pilot in from the muzzle I found there was a definite constriction at the barrel threads, which sounds like where yours was still leading.

No, it doesn't have a restriction there. (I had one gun that had a slight bore variance but I just re-checked & it's good. The largest pin gage (.3458") slides evenly down the full bore while the next size (+0.001") doesn't even start.

When I bought Brownells kit I bought a second set of the brass bore pilots, one for each end of the barrel, verses just the one supplied. I thought it made it easier than using the external muzzle pilot you have to keep one hand on all the time. Also, in one of the guns that I cleaned up the FC, the pilots were very tight on each end. Obviously they were a tad larger than needed.

Oh, my FC looked "threaded" like your's too, just not quit as bad.

Best of luck with it.

.