www.hodgdon.com has IMR4064 loads for 58-100gr bullets for 243WSSM.

Hodgdon now owns IMR.

58 GR. HDY V-MAX
58
IMR 4064
.243"
2.220"
42.5
3698
49,300 PSI
45.5
3966
60,400 PSI

70 GR. NOS BT
70
IMR 4064
.243"
2.280"
40.0
3420
49,100 PSI
43.5
3672
61,900 PSI
80 GR. SIE BTSP
80
IMR 4064
.243"
2.220"
39.0
3250
51,700 PSI
42.2
3458
62,400 PSI

90 GR. SFT SCIR
90
IMR 4064
.243"
2.300"
36.0
2995
54,900 PSI
38.3
3138
61,600 PSI

100 GR. SPR BTSP
100
IMR 4064
.243"
2.300"
35.0
2847
53,000 PSI
38.0
3029
62,300 PSI
PSI