From the Linebaugh Website and a Question

[The Preacher]

"Every action is tightened, aligned, and blocked."

In looking at Linebaugh's website I came across this and have to confess my ignorance...What does it mean to "block" a Ruger Blackhawk action. Thanks.

The Preacher

 

[WOB]

I suspect that they mean installing a bearing block in the receiver to remove all the side play from the cylinder lock or bolt. If you also install a low clearance bolt, then the cylinder is locked precisely wherever the cylinder notch locates it for each chamber. The main benefit from the mod comes only when each chamber is line bored in it's locked position. Otherwise, it doesn't mean much.
WOB

 

[The Preacher]

Thanks WOB. Still scratch'n my head a bit. Where in the receiver is the block placed.

The Preacher

 

[WOB]

The block is placed alongside the cylinder bolt in the bottom of the frame but is inside the frame and invisible when the gun is assembled. Normally the factory bolt has several thousandths lateral play where it protrudes thru the slot in the bottom of the frame window. The block is placed internally and reduces the effective width of the slot to 1 or 2 thou. greater than the bolt width. Therefore, the rotational tolerance of the position of the cylinder is limited to the same small value when the bolt rises up into the cylinder notch( ignoring the fit of the bolt in the notch).

If the locked position holds the chamber on center with the bore, all is well, but that is usually not quite true unless the chambers have been line-bored after the block has been installed. A range rod is the tool used to check bore-chamber concentricity.

The optimum situation is to have all cylinder notches exactly the same width, the bolt sized to fit the notches closely, the bolt slot narrowed by the block to locate the bolt closely, and the chambers line bored when locked in place with the new bolt. So, it's obvious that a frame block is only one step on the road to a well built revolver.

WOB

 

[The Preacher]

I get it now. Thanks much for your detailed explanation. Appreciate your help WOB.

 

[Aggie01]

the bearing block is visible from the top in this single six opened up for a massive (relative to frame size) 357 magnum cylinder.
the bolt is entirely supported laterally by the block, as the original frame slot is gone.

 

[The Preacher]

A picture is worth a thousand words! Thanks again folks.

The Preacher

 

[flatgate]

I've seen instances where the "block" is retained by a screw.

flatgate

 

[Cannon]

Here's another example:

 

[dmize]

Its also how you can identify a Linebaugh by being a "2 pin and a screw".