I have access to a chrono so this will be important as I need to achieve a minimum power factor.
Wobbly commented on this. I will, as well.
As you read in forums like this (even moreso at the Brian Enos forum) about reloading as it relates to action pistol competition, you will read two common bits of wisdom regarding power factor, over and over, where one is gospel, and the other is myth:
Wisdom bit #1 -- Do not load down to the absolute minimum power factor. You want a cushion because if you load to 125, you will eventually have a day when you get chronoed at a match, and due to your extreme spread, a particularly cold day, an unlucky day at the reloading press, or some combination of the three -- EVENTUALLY you will fail the chrono and shoot for no score. This is good advice, and there should definitely be a cushion. Cushions of 128/129/130 are often recommended. To my memory, 130 is the most common recommendation.
Wisdom bit #2 -- At the same bullet weight, lower PF = weaker recoil, and weaker recoil = faster splits and higher scores, so you should load right down to what you consider the minimum PF: 128/129/130 to produce the best scores. MYTH. THIS is bad advice, but commonly given. While there is no reason to go excessively high, and while there IS a point at which recoil is going to affect your splits -- the difference of a few points of PF is inconsequential, so going right to the floor offers no benefit relative to several points above the floor. I have made recommendations to people that would have them at a PF of 133 and had them respond that no no no, 133 is TOO stout and that they prefer to be down around 130.
Here is how irrelevant that difference is: with 124gr bullets, velocity Extreme Spreads of 20 to 30 are considered good, especially with the mixed brass everyone reloads with for action pistol, and up to 40 is not uncommon. With a 124gr bullet and an Extreme Spread of 25 feet/sec, your slowest and fastest bullets have a PF difference of 3. And the shooter can't tell the difference. Extreme Spreads up to 40, still fine, and that has PF swings of 5 from their slowest to fastest bullets. And again, they can't tell the difference in recoil.
PF differences of 3,4,5,6 are insignificant. So do not get hung up on getting that PF as close to the floor as possible.
Where I am going with this, and Wobbly discussed this -- you should load for accuracy. What is your most accurate load in a reasonably low PF range? That should be the goal. I recommend a floor of 130, but look for your most accurate load between 130 and maybe 136/137. I ran some tests a few years ago, and in my CZ ShadowLine, various 124/125gr bullets with a variety of powders peaked in accuracy at an average PF of 133 to 134, depending on exact bullet and powder -- that is where my CZ likes bullets of that weight. 147gr bullets were best at an average PF of 136/137, again based on exact bullet and powder. I have not had much luck with producing satisfactorily accurate 135gr loads in my CZ. It just doesn't like that weight.
But as Wobbly said -- load for accuracy. Within PF range narrow enough that recoil difference remains insignificant, the more accurate load is more valuable to you as a shooter.