When they came out with the 7mm 150 gr E-tip I figured it would significantly beat the 150 ballistic tip, it didn't. Nosler's suggested BC for the 150 E-tip is .498, the BC for the 150 bt is .493.
I may be off but if the BC ratio the same for the 140 bt vs the 140 E-tip it should be this:
140 E-tip .489.9 (estimated), 140 bt .485 (Nosler's suggested BC)
Give them a call and ask them. Post the answer here.
Nosler: 1-800-285-3701