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View Full Version : Help Polishing S&W 686 Forcing Cone (stainless)


detox
12-24-2013, 11:49 PM
Is there a simple method to polishing a forcing cone of barrel that has rough machine marks. Gun is a stainless 686 (1997 vintage) with either 8 or 9.5 degree forcing cone angle...i do not know which angle it is? Brownells sells the 5 degree and 11 degree brass lapping tool, but these are not the correct angle for the Smith. How would you polish without cutting the factory angle?

BTW what is the forcing cone angle for this gun...anybody know for sure? I hear 8 and i hear 9.5 :???: I Googled, but still not certain. Maybe i will contact S&W...
detox
12-25-2013, 12:43 AM
The gun shoots good...i have shot sub 2" groups at 50 yards, but barrel allways has very slight leading in 4 o'clock area after forcing cone ramp.

Here is a 50 yard target example with dirty barrel shot off sandbags. Gun really likes the RCBS 147gr 9mm bullet. The 140gr RCBS Cowboy shoots really well also...better than groups shown in picture.

The awful flyer was shot while shooting at a target seperate from this target. The 358429 bullet was shooting very bad that day (12 inch pattern @ 50 yards). I have since enlarged the front drive band of 429 bullet, but have not tested it yet.

Merry Christmas Everyone
detox
12-25-2013, 11:53 AM
After answering my own question about how to polish forcing cone. Ultimately i think the gun is "not broke in" and needs to be shot more using harder jacketed bullets. This will fix the minor leading...................if all deminsions are correct.
Tatume
12-25-2013, 12:00 PM
My opinion, your last post is the most sensible. I wouldn't touch the forcing cone. Good luck with it, and keep on shooting. It'll get better (and it's already good).
detox
12-26-2013, 02:11 PM
Back when gun was new i shot moly coated jacketed bullets thru it....BIG MISTAKE. IMO moly coated bullets and moly lube is only good after when barrel and forcing cone is broken in. It takes longer to break in a stainless gun.

I just purchesed 3 boxes of the Hornaday 140 XTP bullets. Hornaday quality is verygood and very accurate.
http://www.grafs.com/retail/catalog/product/productId/6335