[cajun_chooter]

because of the shortages i will have to change from 124gr JHP bullets to 124gr FMJ bullets for 9mm.. i am presently loading WST - 5.0gr ---- 124gr PD JHP to a COL of 1.15 to shoot in my STI Steel Match.. .. i noticed of the 2 mentioned bullets there is some difference in length.. are they any adjustments either in powder or COL i should be making ?

[Hoser]

I would back off a tenth or two and see how it goes.

[Boxerglocker]

I agree with Hoser if you extrapolate the bullet length differences you will have less cartridge area with the FMJ. I too would back off the power at least .5g and work up.
For reference I load a Bear Creek 135g moly RN 9mm with WST for my STI Spartan at 1.150 OAL, 4.0g consistently gets me 1000 fps.

[fredj338]

As noted, both, since you are running the top end of WST. In low to midrange pressure leves, not as critical, but at the top end, everything matters. Drop the load back 5% & work it back up.