With regular plated bullets rated to around 1200 fps, I reference lead load data. With thicker plated bullets rated to 1500 fps, I reference jacketed load data. It's been my experience that regular plated bullets tend to lose accuracy at higher than mid-range jacketed load data.
Before you conduct your powder work up, you first need to determine the max OAL using your barrel and dummy rounds (No powder, No primer - Measure some resized cases and use shorter ones) -
https://www.thehighroad.org/index.p...rel-find-a-max-o-a-l-with-your-bullet.506678/
Then determine the working OAL by feeding the dummy rounds at max OAL from the magazine and incrementally decrease the OAL by .005" until they feed/chamber reliably. Now using the max working OAL, you can conduct the powder work up (And once you determine the most accurate powder charge, you can incrementally decrease the OAL by .005" to see if accuracy improves) -
https://www.thehighroad.org/index.p...-and-discussions.778197/page-10#post-11419509
Hodgdon has load data for 115 gr Lead RN -
http://www.hodgdonreloading.com/data/pistol
- 9mm 115 gr Lead RN CFE Pistol COL 1.100" Start 4.9 gr (1,124 fps) - Max 5.4 gr (1,209 fps)
And Speer has load data for 115 gr TMJ which is thicker plated RN that can be pushed to jacketed load data -
https://reloading-data.speer-ammo.c...m_caliber_355-366_dia/9mm_Luger__115_rev1.pdf
- 9mm 115 gr TMJ RN CFE Pistol OAL 1.135" Start 5.1 gr (1094 fps) - Max 5.7 gr (1188 fps)
X-Treme 115 gr RN with working OAL of 1.169" will work with most barrels but I usually load 115 gr RN profile bullets to 1.130"-1.135" OAL (OAL variance typical of many brand bullet nose profile consistency) as when I conducted 1.150"-1.160" vs 1.130"-1.135" OAL comparison test, shorter OAL produced greater accuracy (And I even use shorter 1.110"-1.115" if I want more accuracy).
If your X-Treme bullets are regular plated 115 gr RN rated to 1200 fps, I suggest referencing Hodgdon lead load data for your initial powder work up and around 1.130"-1.135" OAL unless your barrel requires shorter OAL -
https://www.thehighroad.org/index.p...col-for-reference.848462/page-2#post-11465109
And if your accuracy trend improves towards 5.4 gr, you can always test higher powder charges.