I'm wondering if anyone has done any of their own BC testing on the 20 cal 39gr and 40grain Ballistic Tip bullets since manufacture claims are often questionable?
Also, what's the length of the 39gr BlitzKings? I trust Sierra's claimed BCs most. For short range shooting, the BC of the BlitzKing seems to average around .260 or .265 (less the further out one goes). Seems pretty good for a flat-base bullet! But I don't have any to measure.
What's really throwing me off is that Nosler is only claiming a BC of .239 for their 40 grain 20 cal Ballistic Tip, and IMO, Nosler tends to exaggerate their BCs pretty heavy. I would certainly think the BC of the SBK and Nosler BTs would be very very close...but they are pretty far off for some reason.
Finally, Hornady claims a BC of .275, which seems too high on the surface, but if we are to believe Sierra's #s, this makes sense given the bullet has a long boat-tail and a total length of .759" (I measured myself); this is clearly why a 1-11" twist is recommended (.3 longer). I don't have any Noslers to measure, but the length is .730 I believe.
Also, what's the length of the 39gr BlitzKings? I trust Sierra's claimed BCs most. For short range shooting, the BC of the BlitzKing seems to average around .260 or .265 (less the further out one goes). Seems pretty good for a flat-base bullet! But I don't have any to measure.
What's really throwing me off is that Nosler is only claiming a BC of .239 for their 40 grain 20 cal Ballistic Tip, and IMO, Nosler tends to exaggerate their BCs pretty heavy. I would certainly think the BC of the SBK and Nosler BTs would be very very close...but they are pretty far off for some reason.
Finally, Hornady claims a BC of .275, which seems too high on the surface, but if we are to believe Sierra's #s, this makes sense given the bullet has a long boat-tail and a total length of .759" (I measured myself); this is clearly why a 1-11" twist is recommended (.3 longer). I don't have any Noslers to measure, but the length is .730 I believe.
