buying commercial cast is a hit or miss proposition. Most are cast of alloy that is usually too hard so they can be shipped with less chance of being deformed during transit. Also the lube used may or may not be compatible with the loads used. Most of the alloy I use is in the 12BHN range
After experiencing leading with "harder" 20+ BHN commercial hardcast bullets, I ended up with 18 BHN Missouri Bullets that deformed/bumped/obturated the bullet base better to seal the gas and eliminated leading problem with my 9mm/40S&W/45ACP loads -
https://missouribullet.com/details.php?prodId=57&category=5&secondary=13&keywords=
Curious, I tested different BHN/powders/charges and found "softer" 14-16 BHN bullets worked better to deform/bump/obturate the bullet base with lower powder charges and not produce leading like Z Cast bullets -
https://www.jacobeagle.com/bullets
And with even softer 12 BHN, low 4.0 gr charge of Red Dot/Promo worked well to deform/expand the bullet base enough to eliminate leading problem in my PT145 with oversized barrel and produce 2" accuracy at 25 yards with railed Sig 1911 and 2"+ with M&P45 with soft recoil that became a pleasure to shoot even with compact PT145 and favorite of wife shooting M&P45 with small grip insert -
https://missouribullet.com/details.php?prodId=56&category=5
I have only one gun that still leads and it baffles me. CZ shadow 2. even leads up with coated bullets. ran everything from 356 to 359 in it. commercial, home brew. several different weights, profiles, hot and mild loads. all of it leads. Can't see or feel anything that would cause it. Bore is great, no choke points, no bad rifling, nothing pin gages right at spec. walked through every land and groove with a bore cam ... Gave up and run plated through that one.
With any new pistol, my seasoned bullseye match shooting mentor pounded into my head 30 years ago to properly "break in" a new barrel. I shoot several hundred rounds of jacketed bullets to "burnish/polish" bore surface and my various 45ACP (Sig 1911, M&P45, even PT145 with oversized barrel but using softer 12 BHN bullet), 40S&W (M&P 40 and Lone Wolf Glock 22/23/27 40S&W barrels) and 9mm (G22/23/27 with KKM, Lone Wolf, Tactical Kinetics, BCA 40-9mm conversion barrels) barrels do not lead with 12/14-16/18 BHN bullets using lead load data.
If you shot several hundred rounds of plated bullets through Shadow, barrel may be burnished/polished enough to have smooth surface and could try shooting lead bullets again to see if barrel leads.
BTW, which load data/bullet BHN/powder charges were you using?
With 18 BHN MBC 9mm 124 gr Lead RN (SmallBall!, no step RN), loaded to 4.3 gr referencing Hodgdon lead load data, I got full length leading -
https://missouribullet.com/details.php?prodId=51&category=5&secondary=8&keywords=
- 125 gr Lead CN W231/HP-38 COL 1.125" Start 3.9 gr (1,009 fps) - Max 4.4 gr (1,086 fps)
But when I referenced Speer lead load data with lower charges, using 3.8 gr eliminated leading problem -
https://reloadingdata.speer.com/downloads/speer/reloading-pdfs/handgun/9mm_Luger_125.pdf
- 125 gr Lead RN W231 COL 1.130" Start 3.8 gr (911 fps) - Max 4.1 gr (982 fps)
With "softer" 14-16 BHN Z Cast 9mm 124 gr Lead RN (Stepped RN), bullet base seems to deform/expand better even with lighter powder charges of W231/HP-38 and Promo/Red Dot to not lead my KKM/Lone Wolf/BCA barrels -
https://www.jacobeagle.com/product-page/9mm-124-grain-rn-500-count
And with lighter charge "target" loads, not only will using "softer" BHN bullets help with leading but using faster burning powders seem to build initial chamber pressures better to exert pressure on the bullet base to deform/expand to seal better with the barrel to reduce/eliminate leading.
