Is there that much of a difference between Lapua and Sierra?

[Afy]

Loading some ammo for tomorrow...

I seem to be able to Seat my Lapua Scenars in 123 and 139 grains out to a COAL of 2.925 inches and still be about 0.01x off the lands...

However with the Sierra Match King 140 grains.. I just about hit the lands at 2.840 ...

Verified with sooted dummy rounds....

 

[Wil Terry]

You Have Answered Your Own Question.

DO NOT substitute without re-developing the load.

 

[Afy]

Nope...

redoing the load from the Vithavouri and Lyman manuals... and Quickload in conjunction with the optimal barrel time formula.