Revolver forcing cone angle/reamer

[Snapping Twig]

IIRC, S&W uses 18 degrees from the factory, at least on the 686 I sent in for a barrel repair.

I have all my revolvers recut to 11 degrees for lead. I've got a 586-1 recently aquired that shoots so well that I don't know if I'll be sending it off for the change. Tempting, but I'm going to wait a while.

[Ghugly]

Polishing an existing forcing cone is a good thing, but if you have to re-cut it or modify it in such a manner as to correct spitting or accuracy problems, you have a chamber/bore misalignment or a timing problem that needs fixed.

In my particular instance, I was correcting a factory defect. The start of the forcing cone was so small that a boolit sized to groove diameter (.430) could not be started into it as the front driving band was larger than the opening of the forcing cone. The lands extended all the way to the opening of the forcing cone. All I did was ream the cone until the front driving band could comfortably enter the opening. I should ream it even farther, as the opening of the forcing cone is still smaller than chamber diameter. I believe the timing and alignment is, at least, reasonable, as all lead spitting ceased and accuracy was improved. Of course, decent accuracy is difficult to achieve when you're trying to dodge the lead hitting you in the face.

[S.R.Custom]

In my particular instance, I was correcting a factory defect.... I should ream it even farther, as the opening of the forcing cone is still smaller than chamber diameter. I believe the timing and alignment is, at least, reasonable, as all lead spitting ceased and accuracy was improved.

Good show. Although the forcing cone should, as you say, be opened up to catch all of the chamber throat opening, and then some. How much more would be contingent upon the particular gun in question...

The forcing cone picture below is on a Ruger SBH I'm currently working on. I regard it as ideal for this gun, which has more or less perfect alignment and timing. I go a little deeper and wider on S&Ws, as they tend to not carry up as well after they have a few thousand rounds through them. Particularly if the shooter is left handed.

Revolvers have enough free-bore as it is, so I'm not a big fan of 11° forcing cones or, gasp, Taylor throats. In my mind, these are measures that merely treat the symptom, and do nothing to address the real issue. Defective forcing cones like yours not withstanding, I get much better results, accuracywise, by addressing the core problem. In the case of the SBH I'm working on now, there was a slight chamber/bore alignment problem that was easily fixed by "moving" the bolt hole a bit...

[cajun shooter]

The Rugers have used the 5 degree forcing cone since the early 80's. If a beginner trys to use one of the kits with the 11 degree tool, he will cut what is known as compound angle and have all kinds of problems. When shooting PPC in the 80's I would use the 11 degree tool on all of the pistol teams guns. This will stop the shaving and spitting of lead. The guy next to you will thank you. The tool kits by Brownell's are very good in the hands of a good armorer or smith.

[DJWright]

I've done several forcing cones at 11 degrees for cast bullets. Without exception every one shot 100% better after reaming. In the case of one S&W .44 spl. results were amazing. It does not matter what angle the factories use, an 11 degree will work fine with all of them for shooting cast. You just go very slowly by hand with lot's of oil. Takes about 3 minutes.

[Swede44mag]

Have you checked your cylinder throats for correct size if they are too small the gun will spit lead and accuracy will suffer.

I bought a Brownell kit for a S&W 10 shot .22 it was spitting lead real bad and accuracy was non-existent. After using the forcing cone reamer with the gage so I didn't go too far it still spit lead but not as bad. I used a range rod and found out that 3 of the 10 cylinder chambers did not line up correctly. I bought it used I could have sent it back to S&W for a repair but I sold it at the same gun show I bought it at and bought a DW .22 with a 10inch barrel (has a ram on it) the pistol didn't work as a double action. I found out it was made to shoot silhouette and bought the parts from Dan Wesson to make it double action. The bad part is I spent a lot more buying the S&W including trading than it would have cost out right to buy the Dan Wesson in the first place.

Good luck with your forcing cone reamer take it slow and use the right tools I am sure you can make it work.

BTW I have a scar on my left hand where a friends H&R .22 spit lead and took a chunk of hide out.