Multiplying avg G1 by 0.51 will get you very close to the avg G7. In this case, Sierra has used their typical banded G1s, so you will need to make an estimate of the avg G1. However, using their highest banded G1, the corresponding G7 would be approximately 0.311. Although that may be a slight overestimate, it is only slightly behind the 200 Hybrid value of 0.316, and about 5-6% behind the 200.20X G7 BC value of 0.328. It looks like it has a secant ogive, so it might be a little less forgiving with regard to seating depth as some of the other TMKs are reputed to be. I haven't run the numbers, but at the slightly lower weight of 195 gr, it just MIGHT be possible to load these fast enough hit OBT Node 4 at reasonable pressure. Certainly the odds of hitting the OBT node with the lighter bullet are better. The advertised price of the Sierra is about $.05 less per bullet than the typical 200.20X selling price. If their names are any indication, I think the major difference is that there is no guarantee of cleans with 20Xs for the Sierras

.