Forcing cones on 38 snubbies

[overthehills]

I have & compete defensive with 642s at our local club. I have several as they are small & I carry two as EDC. I seem to favor the convenience of small hammerless revolvers (yes I have shot through both pockets of old coats at practice matches after getting clearance from the club SO). I take snubbies seriously and have found the forcing cones of these mass produced and generally seldom fired units to be really rough and foul quickly. I'd like to recut them with an 11 degree cutter but worry I will lose even more velocity than I have already given up with the 1 7/8" barrel. Any thoughts? Thank You

 

[rockquarry]

I'm not an expert. I shoot snub nose J-frame guns regularly and have found they consistently foul less in the forcing cone area than larger-framed S&Ws, so my results are quite different than yours. I must mention that I've had all of my J-frame snub nose .38s anywhere from ten to more than forty years and most have been fired considerably. I wouldn't think of modifying the forcing cone area unless there was a distinct problem.

In addition, and quite surprisingly, using a cast bullet that doesn't "fit" a J-frame .38 as well as it should will seldom lead the bore or forcing cone area, much unlike what happens with a K- or N-frame .38 Special. Just my results based on a good bit of shooting over many years.

 

[BLUEDOT37]

I'd like to recut them with an 11 degree cutter but worry I will lose even more velocity than I have already given up with the 1 7/8" barrel.

Why do think a properly (re)cut forcing cone will loose velocity?

If it allows the bullet to more smoothly transition from smooth-bore/no-spin to rifling/spin, wouldn't that be a plus for velocity?

I have many S&Ws & unfortunately they don't always do as good a job on the FCs as they should but it's my opinion that the two-piece barrels largely have better FCs than the one-piece barrels (yours).

Other than that, I don't know that one frame size or the other is better or worse.

Do you shoot mainly lead bullets?

I noticed on my new J-frames that the cylinder throats are oversized, at .359" (pin gage checked).

I mainly shoot plated or jacketed but lead bullets would be adversely affected by the large throats causing blow-by & flame cutting which will cause leading too.

.

 

[Murdock]

OP: I presume that if you are competing regularly, that you reload. The composition of your load may be a greater contributor to fouling than the forcing cone.

 

[WR Moore]

The forcing cones on J frames can be a problem. I don't know how the factory cuts them, but assuming on a one piece barrel that they're reamed in place, there simply isn't much barrel to make sure the reamer stays properly centered and cuts evenly. Ideally, you want a bore bushing nearly as long as the barrel. Leaving just enough room for the centering cone to properly center the rod.

The other issue is that there simply isn't enough meat in the barrel tenon to work with.

No it won't affect velocity to a significant degree. Don't worry about velocity, worry about shot placement.