Reg
Without knowing your intended purpose for that rifle, there is no way to recommend a good load. Are you going to shoot jacketed bullets or cast.? Do you want a load to plink at tin cans or something with a little more punch for moose hunting?

My 35-40 is based on a 38-55 case and my 35-55 is based on a 30/40 Krag  case but both sre black powder loads with 10 twist barrels. If you want to shoot smokeless  you would have to have  a slower twist and a lighter bullet. I shoot a 345 grain Paul Jones NASA bullet with 46 to 50 grains of Swiss.

Good reply's all and do appreciate it.  Knew I could get usable information here.

RSW  My intended purpose in the long run is for more of a black bear type rifle.  I already have and have used 35 Remington and a Whelen and at least in our part of the country both have proven to be way too much for deer.  Even with called shots the tissue damage is too great and I have stepped back to a 250 Savage with velocities below 2800 fps as a much better ctg.
In the meantime for just shooting it will be used with smokeless only and will have about everything I can find in it even the 158 gn pistol bullets for the grandkids to plink with.

Longdistance  Yes, I have heard to start with 35 Remington loads but could go out to possibly 35 Winchester loads but considering it is a Krag action think I wont push this.  I test fired the barreled action in a tire with 35, 38 and 40 grains of 3031 ( IMR ) and several cast bullets and several jacketed and the light loads with cast bullets hardly fireformed the case but the 200 gn. Hornaday with 40 gn.  looked good for whatever you can learn from primers and sounded good as well.

HiWall  Will be staying with smokeless in the Krag action but if it works out am thinking of making up one on a rolling block action and that one might well see black.

USCRA  So far have only test fired the barreled action tied down in a tire and charges have ran from 35 to 40 grains of IMR 3031 but this was only to see what the chamber looked like.  I used a Clymer 30-40 reamer with a 35 cal pilot to cut the primary chamber then enlarged the throat area with a home ground reamer then cut a small lead with a Clymer throater.  TIR from the fired cases seems to be running less than .001 so will call that good enough for now.  Did Zyglo the bolt head, all looks OK.

Again, thanks to all for the thoughts and ideas.  Am currently setting the metal down into the wood and hope to have it up and running by spring or hopefully before, it depends on how much snow we get.

What I used for a action wrench was a cobbled up mess that in a moment of need cobbled up for another Krag action several years ago.  Got me by then and sufficed for now but if I ever do another Krag action think I will invest the time in making a proper wrench.
Problem with the Krag is the barrel extension is completely round and it in itself is really not correct for applying force .  You need to go to more to the rear into the milled out recess in the forward bottom of the action and tie it into the round extension.  The two areas tied together into one solid piece should be more than anything necessary to r and r the barrel
Fortunately in both of my cases the barrels were not that tightly screwed in and bottomed out unlike a lot of 1917 Enfields one runs across.  They actually came out quite easy and I put them back together a bit tighter than I found them.

I haven't given too much thought as to how I would make a proper action wrench for the Krag as really doubt if another one comes along.  Once they were very common in our neck of the woods but it seems the ones that could be restored have been done so and rightfully so me thinks and the ones that have been modified so much as to make them hard to restore have been put in closets for safe keeping or something.
Anyway if I were to do it , think it should be approached like Dunlap shows in his book.  That is, a separate fitted wrench for each action.  It would be simple to do.  Take a block of one inch steel and bore in the center for the dia of the receiver ring and just have a separate lug welded on to one side to fit into the offset cutout in the forward section of the receiver.  It would take a bit of careful measuring to get the dimensions correct and one would have to allow a couple thousands for clearance.
So far it seems these Krag barrels are not in very tight nor do they need to go back in with great force.  It would be possible to do a lot of damage quick if one were to get too heavy handed.  Am not sure what torque would be proper but what I did in each case was to get a very nice and close thread fit, turn in until a full solid contact then give it a quick sharp "bump" with the rubber mallet I use when tapping in a action for fitting in wood.  It isnt a very big mallet.  It seems to roughly replicate the amount of force it took to unscrew it in the first place.

The picture isnt the best but does show the relationship of the round receiver and the offset flat.

OK, thinking more about it already see one improvement.
I would still make it as described but hold tolerances very tight until it would just barely slip together on the one action.  This especially would be on the receiver ring but also on the lug that would go into the recess on the receiver.
Then, still with it being made on the one inch thick block, I would set up with the block vertical, lay out and drill and tap and counterbore for 1/2" x 13 tpi allen head cap screws on either side, then laying flat again on a saw I would cut the block through on the center line.
What you would have is more along the lines of a typical action wrench.  It would be much more convent to use and be adaptable so to speak for different actions.  A bit more work but more usable.

Exactly.   Only thing I can add is making the lug the pointy end of the handle, all one piece of metal.  Thus there is little stress applied to the weld.   

This has been MOST helpful!   Including the knowledge that the barrels aren't screwed in so tight that they squeak, like some rifles we know.