People the OP is talking about Flat Point bullets it looks like several suggestions might be based on Round Nose bullets. We need to be careful when we make recommendations that we are on the same page.
Yes, OP is using FP bullet which will get seated deeper than RN and thus require smaller powder charge than RN bullet.
9mm ... 124 gr Xtreme FP copper plated bullets ... interested in the COL ... for several different guns (Ruger LC9S, Sig Pro, Beretta 92FS, Taurus PT-111)
When I reload for multiple pistols/barrels, I use the OAL/COL that will work with all the barrels (especially for those with shorter leade or no leade). To determine this "
working" OAL, I do the following:
- First determine the shortest max OAL using the barrels - https://www.thehighroad.org/index.p...rel-find-a-max-o-a-l-with-your-bullet.506678/
- Next starting with this max OAL, determine the shortest working OAL by feeding/chambering dummy rounds (no powder, no primer) from the magazine and releasing the slide without riding it. If the dummy rounds do not feed reliably, incrementally decrease the OAL by .005" until they do in all the pistols - This is your working OAL you want to use for the powder work up.
- My quality control check for testing neck tension is measuring OAL before and after finished rounds are fed/chambered from the magazine. While I prefer no bullet setback, I will accept reduction of a few thousandths. If OAL reduction is more than several thousands (say more than .005") I will investigate why I have insufficient neck tension.
Comparison picture below shows 124 gr RN on the left and FP on the right. While RN loaded to 1.130"-1.155" will work in most barrels, you need to use shorter OAL for FP bullet (essentially FP is RN with tip cut off and added to the base). While FP loaded to 1.060"-1.070" may work for most barrels, you may need to use shorter OAL like 1.040"-1.050" depending on the barrel's leade length and start angle of rifling.
... looking for some data on starting loads ... have Universal, Unique, WST, WSF, HP-38, HS-6, Bullseye
As Walkalong posted, X-Treme's regular plated bullets are rated to 1200 fps with .006"-.008" copper plating thickness and I have used lead load data with good results -
https://www.thehighroad.org/index.p...ng-at-25-50-yards.808446/page-3#post-10470195
BTW, since they are sized .355" I would suggest using .377" taper crimp -
https://www.thehighroad.org/index.p...re-sized-the-same.818806/page-2#post-10567453
Hodgdon does not publish 9mm load data for WST as, depending on OAL/bullet seating depth, compressed charges are often needed for 125+ PF loads and pressure will get spikey at the top. Of the powders you have on hand, I would suggest using Bullseye, HP-38 (Same as W231) and WSF as powder charge levels in the case won't be compressed by deeper seated FP bullet base.
Hodgdon publishes start charge of 3.9 gr for W231/HP-38 with Berry's Thick Plated HBRN (sized .356") loaded longer at 1.150" so I would suggest dropping the start charge to 3.6 gr for X-Treme FP bullet seated deeper in the case. I would test 3.6, 3.8 and 4.0 gr for my powder work up and see how the accuracy trend is -
http://www.hodgdonreloading.com/data/pistol
Current Alliant published load data doesn't offer much help with 124 gr plated FP bullet but 2004 Alliant Load Data lists max charge of 4.9 gr for Bullseye with 125 gr Lead bullet (likely RN) at 1.150" and since Bullseye downloads well, I would use 4.0 gr as my start charge and go lower (so test 3.6, 3.8 and 4.0 gr) -
http://www.thehighroad.org/attachment.php?attachmentid=182147&d=1364769070
FYI, my Bullseye powder testing with Berry's 124 gr HBRN-TP -
https://www.thehighroad.org/index.p...ow-base-rn-for-9mm.581070/page-3#post-7266869