Are these numbers for a rifle or a smoothbore?
All rifle. Few shot smoothies except as shotguns when the book was written
External ballistics in terms of how rapidly a ball loses velocity would be the same
Internal ballistics would vary due to friction with a tight fitting load and in the case of a smoothbore gas blow by. However expanding hot gas converting to velocity would remain relatively the same.
Looking at velocities of a 240 grain .45 conical compared to a 220 grain.54 round ball we see the guns getting similar velocities vs powder charge. With the conical being a bit more efficient in this case solid base conical.
The .54 hollow base becomes almost a carbon copy of the .58 hollow base in the same weight, the smaller being a tad more efficient
One place we see a variance is a ,62 cal ball shot today vs a 320 grain .58 minnie tested by Lyman. Shooters record 11-1400 fps with a ball compared to 800-1000 Lyman was getting with the small minnie. I would suspect the small minnie was real poor at using the gas, and suffered a lot of blow by before expanding.
On the other hand in air the 320 grain minnie performed about the way a ,62 ball of near the same weight in terms of maintaining velocity mid range trajectory
While smaller bore rifle won’t carry over one to one to large bore smoothies I would hazard the trends are the same.
Reading Lyman we see shots fired under controlled conditions at constant temps. What can .54 data from Lyman tell us about cold November morning in the deer woods?
We probably get lower performance from our guns in the field then Lyman got in test, but the trends would remain constant
So I THINK the data is applicable even if the numbers are not directly translatable