Data from the Hodgdon Site for the .41 Magnum:
210 GR. HDY XTP 210 Lil'Gun .410" 1.580" 20.5 1505 23,500 CUP 22.5 1626 29,900 CUP
220 GR. SPR JSP 220 Lil'Gun .410" 1.580" 18.0 1431 24,300 CUP 20.5 1563 31,200 CUP
250 GR. WFNGC 250 Lil'Gun .410" 1.540" 17.2 1399 30,300 CUP 18.3 1474 36,700 CUP
255 GR. WFNGC 255 Lil'Gun .410" 1.660" 18.8 1424 26,600 CUP 20.0 1500 32,800 CUP
265 GR. WLNGC 265 Lil'Gun .410" 1.710" 20.0 1479 28,700 CUP 21.3 1558 35,400 CUP
As for the .357 Magnum, as said above I also find Lil'Gun works very well with heavy bullets in the .357 Magnum. (170-200gr) H110/W296 still works better with 158gr bullets and lighter IMO. With heavy bullets you get higher velocities with lower pressures without sacrificing accuracy.
Here is the data from the Hodgdon Site for .357 Magnum and Lil'Gun:
158 GR. HDY XTP 158 Lil'Gun .357" 1.580" 16.0 1504 24,100 CUP 18.0 1577 25,800 CUP
170 GR. SIE JHC 170 Lil'Gun .357" 1.580" 15.0 1422 25,100 CUP 17.0 1576 35,500 CUP
180 GR. NOS PART 180 Lil'Gun .357" 1.575" 13.0 1279 27,500 CUP 15.0 1422 34,500 CUP