Most 4140 steel for barrels have a heat treat that takes them to 28-32 Rockwell C. After button rifling they barrels are stress relieved by heating them but not to the point that the hardness is effected. 4130 steel that is used for liners is also used as aircraft tubing, not as hard but more ductile, meaning it can flex a little without breaking. Old black powder barrels were not very hard. Had an 1886 barrel sent to me that was bent in several places. The story is that the wagon got stuck and they used the rifle to pry it out of the mud. When rifles went to smokeless powder they needed a tougher steel. The 1894 Winchester was made in 32-40 and 38-55 the first year because they did not have the Nickel Steel until 1895, that's when the 30-30 and 32 Special was introduced. Some of the German barrel were marked Krupp Steel which is very tough. 
I have lined higher pressure cartridges but now I recommend making new barrel for thing like 30-30 and up. Not because I'm worried about the pressure but the ware factor with the higher velocity and jacketed bullets.  If a liner is installed correctly there should not be a problem with pressure unless the chamber is too big for the wall thickness, the original barrel should hold the pressure. The liners I use are hammer forged which makes them a bit harder but still not close to the modern 4140 barrel. The stainless steel used in rifle barrels is 416 and not near as tough as 4140. The reason for using stainless in target rifles is the throat does not flame cut like the high carbon steel barrel, can't cut stainless with a cutting torch.
Hope this helps.

A few years back Jerry Cunningham ( Orion Barrel) made a 300 Win. Mag out of 12L14 just to prove that it would not blow up. He did a bunch of test on muzzle loading barrel to see if he could get one to blow up. This was after someone said that 12L14 was not strong enough for barrels. I had the same thing said to me for using DOM for a muzzle loading barrel because it had a welded seam. As far as I know most of the old original muzzle loading barrel were forged welded. 
The only reason I recommend 4140 over 4130 for high velocity jacketed bullets is that I think the tougher steel will last longer . This a personal opinion and I have no proof to back it up. I have been installing liners for over 20 years.