For CZ's and the Smith, you probably can't exceed 1.125". I would put a bullet in a FIRED case and push it into the chamber, either by hand or with the aid of a plastic mallet. When the casemouth stops in the chamber remove the dummy round and measure its OACL.
For me, I then load .005" shorter than the measured length. This will establish freebore. I also increase the amount of freebore if the press will not hold a +/- .001" tolerance for OACL. Example: if your press yields a variation of +/- .003" OACL I would increase freebore to .008", which based on a measured OACL of 1.125"/28.5mm using the dummy round, would mean you'd set the seating die to yield an OACL of 1.117".
For SIG, Ruger and several other pistols, I use an OACL of 1.142"/29mm with the 124 gr. Golden Saber and load into the +P velocity range.
While this bullet is a great buy as far as JHP's go, don't let that fool you. At +P velocity there aren't many bullets that will exceed the performance. The Remington standard 124 gr. JHP has always been a more accurate bullet in my pistols and I use them a great deal. But, for years I used the GS and field tested with water jugs in front of, and behind wet newsprint, as well as recovering bullets from sand berms. Especially after Remington debugged the core separation issues this bullet had very early on. Recovered bullets were more than impressive and I've routinely had expansion to .700"!