What do real gunsmiths do for barrel vise blocks for full underlug barrels such as the 586/686 ?
I spent about 2 hours this morning making a set of plastic barrel vise pads for a 586 I was working on.
None of the sites I found with action wrenches and barrel vises for sale sold anything specific for full underlug revolver barrels.
Do reals smiths custom make them for all the different possibilities ?
or do they just put them in padded plain vise jaws and go for it ?

I would think Pro's would make their own for commonly worked on Revolvers out of wood.

I had mine made for me by another guy in the shop who did machine work.

They can be made of brass, aluminum, or hard "engineering grade" plastics.
Construction is fairly easy.
The Jerry Kuhnhausen Shop Manuals usually have pictures of his barrel blocks in action.
The outsides have ledges to position the blocks in place, and the inside is made by drilling figure-8 holes in a block and sawing it in half.

For a "one time" job I made them by using two hard wood blocks and epoxy.
I'd route a groove larger then the barrel in each block, wax the barrel with Johnson's Paste Wax or another release agent, then fill one side with epoxy and put it on the barrel.
When cured I'd mark which side the block went on and which way was toward the muzzle, then do the other side.
After cleaning up, the blocks would clamp on the barrel with at least 1/8 inch between the two.

Whatever you use, keep the blocks CLEAN.
Before use I'd use a solvent liker alcohol to clean the blocks and dry before mounting the barrel in the blocks and into the modified vise I used.
I'd also clean off the barrel.

After doing the job, the blocks were again cleaned and dried and stored in a CLEAN plastic bag until needed again.
At NO time were the blocks tossed on a dirty, gritty bench or put on a dirty barrel.
Customers have a funny thing about scratches or marring on their barrels caused by bench grit that was embedded in the blocks.

My vise was a medium size Wilton round shaft with modified jaws to hold the barrel blocks.
I picked up a used Wilton and had the jaws modified to hold the blocks with the frame upright and the barrel down.
This is much easier then trying to work with the frame and barrel horizontal.

For the past couple of decades I have been using a piece of full hide leather for the barrels.

I've been changing revolver barrels for over 30 yrs. by using two SOFT wood blocks that measure 2"x5"x3/4". I clamp them over the frame using two 4" C-clamps. I remove the cylinder and replace the yoke in the frame. I then clamp the barrel in freshly cleaned polyester blocks sold by Brownells for soft clamping in vises. I turn the barrel so the underlug rests firmly against the side it will torque to. For 95% of S&W barrels I can unscrew factory installed barrels by just using my hands clad in leather gloves and grasping the two C-clamps. Rarely do I have to clamp a lever to the wood blocks to break the factory bond. When the wood blocks show sign of splitting I just cut a couple of new and start anew. I mark the blocks as to J, K, L or N frame. Reinstall is just a reverse of the procedure. By replacing the yoke in the frame while removing or reinstalling any possible frame damage is reduced to nothing. I fit a new barrel to clock to about 10 deg. remaining to turn to TDC for a K frame (less for larger frames) and then use an anti-seize compound on the flat mating surfaces and none on threads. It is not a good idea to be excessive on the amount of re-installation torque required when working on S&Ws.

Thank you for all the insightful replies
I finally put up a link to a pic of my setup
I learned the hard way if you need more force than a 2x4 can support you are going to wreck something
This worked very well but making the vise block bushings was rather tedious
The action wrench bushings are the commercially available ones

https://onedrive.live.com/redir?resi...nt=photo%2cjpg

That's sort of a non-conventional setup but looks like it works just fine.
The only thing I see with it is that it would be a little slower then the block sets I used and possibly not as solid a set up.

I found over the years that when working professionally it pays to use correct tooling for the job.
Customers tend to get upset for some reason when a gunsmith tells them their beloved revolver frame cracked because the 2x2 through the frame failed to prevent it from bending or cracking.
Working on your own guns is one thing, other peoples is another.