No.
Barrels are drilled with tools like this:
View attachment 1088151
Cutting fluid is pumped under pressure through the holes to force evacuation of the chips. And, the final pass with a gun drill will only go one direction, you do not withdraw them, but disconnect them and pass then through the work.
View attachment 1088152
That barrel looks as if the cutter insert chipped about 1/4 inch into the final cut. It wasn't exactly super sharp to begin with, either. Also, you can tell that the rifling was button formed, as it just pushed over the poor surface finish of the boring. Cut or broached rifling would have cut out the bad sections.
Your photos of deep hole drills ( the single-flute types) do show the type of cutting tool used to establish the bore through the solid barrel blank - it is pushed through the blank which is rotated at high speeds (the drill does not normally turn), and the chips are flushed out through the channel in the drill rod. The finish of a properly drilled hole is usually not as rough as shown in the OP, but is, in any case, considerably under the desired diameter of the finished bore. The final bore diameter is established by reaming, with one or more reamers which are pulled through the drilled bore of the blank, which is rotated at considerably lower speed than in drilling, and also with coolant flood through the reamer rod. Any tool marks remaining in the finished bore are those left in the final pass of the reamer (assuming the maker actually reamed the bore; which, in the OP, looks like the work of a dull twist drill). Those circumferential tool marks after reaming may be so insignificant as to need no further work to improve the surface finish, but can be improved before rifling by lapping, electro-polishing, etc.. Cut-rifling processes (single-point, broaching) will leave tool marks running lengthwise in the grooves, and, again, with properly designed, operated and maintained tooling, may require no further finishing operation after rifling, but can be improved by the same methods as bore finish. Rifling broaches are long, tapered cutting tools with ganged teeth of the desired rifling pattern, increasing in height and on the desired rifling pitch - they must be rotated mechanically as they are passed through the bore (though the same result can be achieved by rotating the blank), because it cannot rotate itself. Broaching may be accomplished with one or more broaches - rougher and finisher - for best finish and groove diameter control. Button rifling is produced by passing a very hard (usually a carbide) tapered 'button' with the desired shape, pitch and dimensions desired in the finished rifling - it can be made to smooth the remaining bore surface (the lands), also, and will lead itself through the barrel on the pitch established on the button, but can be 'helped' through the bore mechanically, to keep the final pitch as uniform as possible (button rifled barrels can have slightly inconsistent pitch due to variations in the hardness of the barrel material at different points in the blank). Hammer-forged barrels are made by passing a mandrel of the desired pitch and dimensions through a short, fat blank with an established bore, hammering the blank with great force to close the material around the mandrel while withdrawing and rotating the mandrel as the work progresses, producing a finished rifled bore and external dimensions of the blank - the chamber can also be established in the same operation. Hammer forged barrels will usually have the best interior finish, if the mandrel is properly made and maintained - the barrels pictured above are almost certainly hammer forged. The drawbacks to hammer forging are that the equipment is massive, very expensive, and the mandrels are not only expensive, but subject to breakage. There is another, fairly recent method of rifling: EDM, but that, too suffers from some drawbacks, in that the equipment is expensive, uses large amounts of electricity, and also requires a specifically-designed electrode for each rifling pattern and caliber to be made. EDM can produce very good barrels, but is not a widely used process ATT.
NOTE: No barrel making process or barrel maker I have knowledge of uses a boring bar for any step in producing a barrel blank.
PRD1 - mhb - MIke