120 vs 123

[Dub]

In general, the 120's were first made, and they have a tangent (a bit more stubby) ogive.
The 123's were made for the Grendel, and have a secant (longer, sleeker ogive) ogive. Usually also a higher BC.
The 120 is more forgiving in terms of OAL seating distance from the lands, where a secant ogive can be more picky.
A 120 will probably need to be seated a bit shorter as to OAL.
Either one can shoot fine in a given barrel.
The sierra 120 SMK is often used on here as a "proof" bullet, if a barrel can't shoot the SMK decently well, probably won't shoot anything well.

Thank you for all the insight.

Really helpful.