Reducing number of No.4 Barrel grooves to speed production?

[CINDERS]

I think the 2 groovers are easier to clean IMO and given as stated larger bearing surfaces translated to greater accuracy, one can procrastinate on what's good and what isn't but when you think of the phases of production and War time pressures it really was a bit of rafferty rules if you got a shooter being at the lower rung.
Then you probably wouldn't as they would have been pulled from service after accuracy testing to give to the Marksmen, or fitted up into Sniper config.

To think of the 303 barrels being straightened by eye and a hammer then that is the real skill knowing where and how hard to strike the barrel to straighten it all through looking through it and the light reflected from inside the bore that is a real art long lost I surmise.
As now days you can have what you want and the limit is only determined by the length/depth of your pocket, all machined polished air gauged, lapped and yada yada with whatever your desire takes you I think Bartlein offers gain twisting as the Carcano rifles had in WWII (I might be mistaken there with the Carcano!).

P L did they ever do that type of thing when you were in service, hand straighten the barrels the old way or was it by eye and press or just machine.

Just like the old ways of making cars as Wes Harrison said you push the side of a car in now days and you get the ding but not the boing of the dent coming out!