I have had two custom 17 Remingtons, one with a lilja barrel and the other with a Shilen barrel. Also, 4 of the 17 Mach 4's.
I had the reamers ground where I could just clean up the necks to give better uniformity.
Using 22.5g of H322 with a 25g Berger I got 3850, and with this speed I could go long strings on p. dog towns.
For coyotes, I shot 24g of IMR 4320 with the 25g berger at 4100.
Groups with the 25g Bergers were from the high 1's to low 3's, and they killed coyotes quite well. I noticed that I got a lot less copper fouling with the Bergers vs the Hornady 25g HP...understatement.
Lilja and Shilen barrels will have several features that are well worth considering:
1. uniform bore dia
2.drilled much straighter
3. micro finish of the bore will be slick as glass
4.ease in cleaning
These two custom barrels will be a much better barrel than any factory barrel, and this should only be a consideration if you want to shoot long shot strings and ease of cleaning.
If you do go for a custom barrel, make sure of the reamer dimensions. You want a reamer that does not give you a big sloppy chamber, and a short leade is preferable. A gunsmith that has a set of reamer pilot bushings to match the ID of the bore perfectly is a must. Also, if he has a uni throater to throat for a 30g vs zero to next to zero freebore(20-25g) would be preferable. It is very impressive to see a rifle shoot a five shot group smaller than a pencil eraser!
These small groups will give you instant confidence when you happen to pick up a coyote staring at you over the top of a bush with only his head exposed at 250 yards and further!
The gratification of shooting a rifle that kills way out there that has the recoil of a BB gun is something that you will just have to experience.