Lead Splatter

[JudgeBAC]

An interesting problem has risen lately in two N frame Smiths. The first is a M57 6" .41 magnum. Shooting any cast boolit of any size and with any lube resulted in lead accumulating on the cylinder above the chamber area. It looked like lead was spattering off the forcing cone and perhaps on the underside of the frame window and depositing lead on the cylinder.

Taking a close look at the forcing cone, it appeared that the gun really did not have one. A trip to the gunsmith solved the problem until I shot some commercial cast 230 gr. sized .411 BHN 13. Shooting this boolit resulted in the same problem. It appears that this gun likes its boolits sized .410. By the way, I have never had this problem in any other gun with cast boolits of varying diameters. No ruger single action or double action has ever had this problem.

The second gun is a new M29-10 Nickle 6.5" Smith .44 magnum. After experiencing the same situation, I had the forcing cone recut but boolits sized .430 deposited the lead on the cylinder.

I am assuming that this is a sizing issue since the .41 shoots without deposits at .410 and the .44 shoots deposit free at .429 although I cannot understand why the problem has never arisen in any other handgun I have used for cast boolits.

Any ideas?

[Bass Ackward]

Some guns just prefer bore sized bullets. There can be multitudes of reasons why, but that would be just speculation without seeing the gun and then my interpretation could be wrong.

Since you asked, a guess here is that most of the time it's strictly a pressure issue. If the gun throat / forcing cone / rifling / wide band bullet retards the front of the bullet for any reason, the base is going to feel it. (Smiths have that wide rifling configuration that requires more lead displacement and thus time for this to occur. If these are new Smiths with the angled rifling, then even more lead is displaced.)

Have high pressure break on the face of the cylinder as the base clears and you will get a certain amount of cutting. (Supposedly a positive to bevel base bullet designs.) Normally lead is blown clear, out the BC gap by this same pressure. Could be your BC gap is a little tighter on these guns too. All guesses.

Chances are, as your guns break in and everything wears, you may gain back some flexibility for diameter variance. Another reason I hate new handguns or old guns that have work done to them. Just about any work starts the break in process all over again.