Endshake

[magnumz]

I have a Super Blackhawk that has some endshake. When I measure the cylinder gap with the cylinder pushed towards the barrel, it is .004 inch. When I push it back towards the hammer it is .009 inch. Is this too much endshake or do I need to have it corrected and if so, what is the best way to do it?

[Boxhead]

With .005" of endshake it is time for a repair. Sending it to Ruger is probably the best option. I have also had Alan Harton weld up the gas ring and essentially remove all endshake. 'Also, smiths also install bushings (I think Ron Power makes them) to fix it.

[WL44]

Boxhead is right - Power Custom sells what I think they call a base pin bushing. You can match up the ID to the base pin OD.

By the way, my SBH has plenty endshake too, but it really hasn't been shot that much or been treated hard at all. If you put the ammo in the movement is limited by the thickness of the case rim. Measure it like that and look at the numbers again.

I don't have experience to say, but was wondering whether that's "normal". In my case it's certainly not due to use.

[Flint]

Two things to correct the endshake, after stretching the gas ring, you'll have to set the barrel back to close the cylinder gap.  As WL44 suggested, see if the endshake and cylinder gap are excessive with cartridges loaded.  If you just lengthen the gas ring without checking headspace, you may close up the headspace and prevent loading the gun.

When adjusting the cylinder, the headspace must be set first.  Then if necessary, adjust the endshake and cylinder gap.  Ruger probably had a decent cylinder gap on the gun, and perhaps Magnum ammo battered the rachet teeth shorter and allow the cylinder to move rearward.

If there is insufficient headspace (measure unloaded), there is little you can do about it short of turning a few thousanths off the rear face of the cylinder to effectively lengthen the rachet which bears on the frame, or install new cylinder if you want perfection, or rebuild the rachet teeth.   All that's expensive and not necessary, for if the cartridge rims move the cylinder forward enough to close the endshake and cylinder gap to a reasonable amount, just let it be.

The worst case of excessive headspace and/or endshake would be the inability of the firing pin to reach the primer.  The few thousandths you have aren't near that point yet.