The Remington 102 gr golden saber has a published velocity of 940 fps with 200 ft pounds of energy and a power factor (mass x velocity/1000) of 96.
For SAAMI spec ammo it's a 9 in terms of energy and a 10 in terms of momentum. For comparison:
Win PDX 95 gr JHP at 1000 fps for 211 ft pounds and a power factor of 95.
Speer 90 gr Gold dot at 100 fps for 199 ft pounds and a power factor of 90
On the low end of SAAMi spec loads, you'll find loads like the 90 gr FMJ at 920 fps with 169 ft pounds of energy and power factor of 83, and lighten loads like the Buffalo Bore 70 gr glaser 1200 fps for 224 ft pounds but a power factor of only 84.
However, there are also some non SAAMI spec loads by Buffalo Bore:
95 grs at 1125 fps for 267 ft pounds and a power factor of 107; and
90 grs at 1175 fps for 276 ft pounds and a power factor of 106
100 gr at 1125 fps for 280 ft pounds and a power factor of 112.
If you include those loads on an absolute scale where power factor varies from 83 to 112 with a range of 29, and a resulting 2.9 per numeral on a 1-10 scale, the 102 gr Golden Saber is then only a 4.5 - which is a good indictor how far over SAAMI spec the Buffalo Bore loads are, and how hard they will work your pistol. If you are planning on using hose loads i would not break the spring in, and I'd replace them often - maybe every 100-200 rounds, and quite frankly I would not use them on anything approaching a regular basis.
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For your purposes where you plan to use Federal FMJs, American Eagle has a 95 gr bullet at 960 fps with 194 ft pounds of energy and a power factor of 91. Wolf, Prvi Partisan and Magtech FMJ loads have the same power factor.
102 gr Golden Saber is a bit above those, but it's over kill just to break in a spring. Shoot your pistol with what you plan to shoot and call it good. Abusing a spring first won't add any benefit in terms of wear or reliability.