Buy some CCI .22 Long ammunition for your .22 long revolver.
Better yet buy some low power CCI .22 Long CB ammunition.
CCI is the only American Company still producing cartridges in this configuration.
.22 Long revolvers have a 1 in 12 or 1 in 13" twist designed to accomodate the 36-39 grain .22 short bullets that were loaded into the longer 'long' case.
40 grain .22 long rifle bullets won't shoot worth a hoot in these old guns even if you can get the cartridges to fit in the cylinders.
In addition these old revolvers were not the pinnacle of the gun makers art and even standard velocity .22 long rifle ammunition will put more strain on the gun than it was designed to tolerate.
Modern .22 shorts and .22 longs generate about 19,000 to 21,000 foot pounds of pressure.
Believe it or not, modern .22 long rifle ammunition generates 36,000 to 39,000 foot pounds of pressure.
The result of shooting the wrong ammunition in these older revolvers will be a broken gun in a suprisingly small number of shots.