Just last night, I did the same thing loading up some various different powders in the 7mm-08, experimenting with a given bullet (Remington 140gr Cor-lokt) and previously determined seating depth (2.830"; 2.850" touches the lands in the throat).
When charging with 41.0gr of RL-15 (VERY ACCURATE, btw.) I had a bit of space left in the case.
When using RL-19, the 48.0gr charge came half way up the neck. Upon seating the bullet with the same setting on the seating stem, I got an OAL of 2.838", requiring me to reset the seating stem to get the proper OAL of 2.830". The resistance of compressing the powder resulted in a slighty longer OAL. This is due to "tolerances" in the press/loader "springing" or flexing under the increased pressure of seating the bullet and compressing the powder charge.
Both loads chrono's ~2,750fps, and both are amoung the 3 most accurate loads I've used. It just requires a little "manipulation" to get things right.
BTW, the Rl-15 load is 2.0gr below the book max. (Alliants), and the RL-15 load is 2-5gr below listed max, depending on who you reference. How Alliant got 50+ grains in that case and seated a bullet over it is beyond me! I used both a drop tube, and touched the case head to a running vibratory tumbler to get it to settle. I still can't get over about 49.5gr of RL-19 in the case, either PMC or Winchester, and seat a bullet over it.
So, thats why reloading is both an ART and SCIENCE.
(I suspect that the lot# of the Data powder, was a bit denser than the one I have. Kinda funny, as I get higher velocities at the same charge weights with RL-22 as compared to RL-19 in the .30/06, both being compressed charges! RL-22 is SUPPOSED to be slower burning than RL-19. Kinda like H4831 compared to H4350.
P.S. The RL-15 load under a Sierra 140gr BTSP loaded to 2.815" (2.825" touches the lands) gave me the best accuracy to date from my Rem Mod-7; 4rds touched, with #4 of 5rds going ~1/2" high for a ctc. 0.850" load. (the four touching were under 1/2" ctc.) Chron'o showed 2,740fps, with max spread of 62fps. A real winner for a 7lb rifle! The Sierra's are a bit tighter in weight tolerance. Uniformity of the jacket and core seem to be a bit better.
The Cor-lokts performed exemplarily on the deer I've shot with them though.