Forcing Cone Circular Ridges

[accuracy@25]

The barrel forcing cone on a S&W 44 Spl is very rough for a revolver that is only approx 3 yrs old. The forcing cone contains circular ridges, could be grooves, as it leads into the rifling. How can I go about smoothing these ridges or the entire forcing cone area. I recently used a Lewis Lead Remover to "clean up" the forcing cone area from lead deposits--did a good job. I have a gut feel if the area can be "dressed" it may improve accuracy.

 

[Old Dog Man]

Rough forcing cone

There is a tool that will re=cut the forcing cone and make it the proper depth if it's not already cut too deep. I'ts available from Brownells. com it comes with cutter and depth guage, works very well, or take it to a smith that has the tools. Al

 

[rcmodel]

http://www.brownells.com/.aspx/cid=11508/Products/Chamfering-Tools

http://www.brownells.com/userdocs/documents/Inst-152.pdf

rc

 

[accuracy@25]

Old Dog Man and rc model: thanks for your input. I'll look up Brownells. Paul

 

[dfariswheel]

If you want to do this yourself, buy the special plug gage to measure the forcing cone.
THE critical dimension is the outer mouth of the forcing cone, not the depth or angle of the cone.
You cannot eyeball the mouth and if you get it too big or too small accuracy will suffer and if too small the gun will spit bullet material.

If the cone is properly cut, (and most are) all you may need to do is lap the cone with the brass lap and some fine valve grinding compound to smooth it out.

 

[Jim K]

Are you sure you got all the lead out with the Lewis tool? It sounds like those grooves might be just stubborn lead deposits. It depends on how much you have shot, but having a forcing cone go bad from .38 Special is uncommon unless the loads are very hot (close to .357 velocity) and a lot were fired.

Jim

 

[accuracy@25]

dfariswheel--I have no doubt that the cone was cut properly. I think the cutter however was rough. This is basically a new smith with approx 100 rounds fired. You indicate a brass lap with fine compound. Is the lap a tapered lap (special purchase from Brownells) or just a round lap. Thanks for your input.

 

[dfariswheel]

The lap is a tapered lap, matched to the taper of the cone.

Buy them from Brownell's. They also sell various lapping compounds. Silicone carbide is the best because it embeds nicely in the brass lap. Be VERY sure you completely clean all the abrasive from the cone before shooting:

http://www.brownells.com/.aspx/pid=26155/Product/BRASS-LAPS