Is this true

[flanman]

Was reading some articles posted on the internet when I came across a paragraph describing the importance of reaming th chambers of cylinders that are made for 357 yet are used mostly for 38Spec. The argument was that the shorter 38Spec will leave a ring of carbon and debris that then narrows that chamber and when 357 ammo is used there is increased pressure generated leading to potentially dangerous outcomes. First I hear of this any thoughts?

flanman

[porsche]

It is possible yes. With through cleaning it is minimized. Some use an empty 357 case with a handle on it to help remove the accumulated crud. Run a small drill through the primer pocket of empty 357 brass and put in a screw or something in there and solder it into the hole. This is a handle to put case all way into chamber and twist it on the crud to help loosen it. Some even file teeth on end of brass case to make it cut.

[Kid Sopris]

A regular and thorough cleaning is all that is required..In real severe cases some J-B Bore cleaner will work equally well. No need to "Bubba Engineer" a serrated case and possibly ruin your revolver.

[A1A]

It is common, but I'm not sure about the pressure scare. Usually it shows up as the inability to completely chamber or eject a 357 easily or FTF because the final seating absorbs some of the fp striking force. Regular cleaning with a proper chamber brush after shooting 38s is a good idea. BRONZE RIFLE/PISTOL CHAMBER BRUSHES - Brownells

[diamonback68]

flanman, it just makes sense. You have a longer cased 357 that rests on a cut inside the cylinder chamber made for that round. When you shoot shorter .38Specials the unburnt powder and crud build up on that lip and make it difficult to rechamber .357 after that. Not sure it causes higher pressures, but it can make full seating of the 357 difficult or if round is not fully seated can cause occassional misfires from the cushioning affect of the crud.

[y2kdon]

I had heard about this possibility when I first started shooting my 357. My solution since I was also getting in to reloading, was to use only 357 brass and to have 3 levels of reloads. 148gr. wadcutters loaded to 800fps for the wife to shoot and for when I carried a guest to the range. 158gr. semiwadcutters loaded to 1100fps for me to use as my primary target load. 125 gr. JHP at 1350 fps for when I wanted to make a little noise!
The different loads are easily identifiable at a glance. Problems with chamber buildup are minimized.

[Queen Anne's Revenge]

Well, rimmed cases headspace on the rim, not neck. Of course, the chamber will be a bit longer for the .357.

[Colt-SL]

In my personal experiences it generally depends on how much the gun is shot and what types of ammo are shot from the gun. In .357's that I've shot extensively with lead bullets, there is a build-up of lead in the chambers and the barrel bore. Lead remover kits use what looks like small, round screen devices that ream the powder residue and leading. In some exaggerated cases, until the lead cleaning was done, you would not have an easy time of loading a .357 case into the chamber after the .38 spcls have been fired. Like most everyone else here though, I see little safety worry in normal shooting, especially if jacketed bullets are used. In that scenario, just a good, standard cleaning is indicated.

[ralph7]

i cut the handle end of a bore cleaning rod off so i can chuck it up in a drill.
a slowly spinning brush wears the brush faster, but will safely clean a chamber a whole lot quicker.
i use it on my .22's after shooting powderless shorts indoors more than anything.

[Merwin2]

Solutions looking for a problem. Clean your gun throughly after each session and it won't be a problem...trust me, unless of course you're using black powder in your hand loads.
Merwin2.