Court found no error in the trial judge's decision to admit: A motion founded on affidavits, among them an affidavit by an expert on firearms who had testified for the Commonwealth, as well as a motion based on affidavits by experts tending to show that the revolver found on one of the defendants could not have been the revolver which formerly belonged to the murdered man and that the revolver found on the other defendant could not have discharged the shells found near the scene of the shooting nor the mortal bullet, where it appeared that the judge declined to believe the experts for the defendant [***76] as against the experts for the Commonwealth and the jury's finding.