So this is for desktop ballistic nerds. On the surface the 123 scenar seems to be a superior bullet than the 139 scenar if you go off lapuas G7 BC and form factor. 123 G7 .263 form factor .958 vs 139 G7 .290 form factor .982.
If you go to JBM and use the lapua CD figures for both the 123 and 139 scenar the 139 performs better vs the standard G7 and the 123 performs slightly worse than the G7.
As an example using equivalent muzzle energy figures which gives a fair comparison running the 139 scenar at 2750fps the equivalent muzzle energy for a 123 is 2932fps. The CD figures don't give a BC but I played around with the blank values in the bullet section of JBM and changed G7 too match the wind drift figures I get for 1000m with those of the CD drag values and I get approx a G7 of .296 for the 139 scenar vs G7 of .262 for the 123 scenar to match drift figures of the CD values. This is just desktop ballistics so don't take it too serious.
This corresponds to an approx form factor of .962 for both bullets putting them as equal performers when pushed at same muzzle energy.
If you go to JBM and use the lapua CD figures for both the 123 and 139 scenar the 139 performs better vs the standard G7 and the 123 performs slightly worse than the G7.
As an example using equivalent muzzle energy figures which gives a fair comparison running the 139 scenar at 2750fps the equivalent muzzle energy for a 123 is 2932fps. The CD figures don't give a BC but I played around with the blank values in the bullet section of JBM and changed G7 too match the wind drift figures I get for 1000m with those of the CD drag values and I get approx a G7 of .296 for the 139 scenar vs G7 of .262 for the 123 scenar to match drift figures of the CD values. This is just desktop ballistics so don't take it too serious.
This corresponds to an approx form factor of .962 for both bullets putting them as equal performers when pushed at same muzzle energy.
