The faster you push the bullet, the slower twist rate is needed.

This is just as confusing to some as the BC at a certain velocity… You need a certain twist rate for a certain velocity.

So maybe 1:8 is OK but only if you run it fast enough.

I think you are correct, an 8″ twist will handle the Sierra 6 mm, 110 gr. MatchKing but probably not at 50-feet AMSL, 20 deg. Fahrenheit, 30.50″ Hg corrected barometric pressure and 3000 f/s muzzle velocity.

Now at the Whittington Center in the Summer, there is no question, an 8″ twist is adequate for about Sg = 1.5 for the 110 gr. MK.

Please, as a matter of interest, in what conditions did the 8″ twist handle the new 6 mm Sierra bullet.

Henry

Thank you!

This problem isn’t helped by catalog companies like Midway that only have one number for BC and simply print the highest number with no mention of velocity bands. If this was your only source of info, it’s certainly misleading.

Also, It’s been quite some time since we’ve (Applied Ballistics) measured the MatchKing line of bullets and many of them are now being pointed. This is the case with the 107’s discussed above. We’re making it a priority to update our measurements for bullets that have changed and will be re-measuring the entire MatchKing line of bullets for re-publication.

As far as performance goes, this new 110 SMK looks pretty good. Just be careful to consider the whole range of velocity-BC’s, and not just the high velocity numbers.

Sierra was perhaps the first to acknowledge the velocity dependence of BC’s and offer the velocity banded solution for G1’s. Over the years they’ve suffered from this approach because of shooters only looking at the high velocity number and then accusing Sierra of inflating BC’s. The solution is to provide a single G7 BC, averaged over long range. Nearly every other major bullet company (Berger, Hornady, Nosler, Lapua, and Barnes) have adopted G7 BC’s in recent years. Sierra has the ability to do the same if they chose. Either way, AB will continue to provide independently measured G7 BC’s for all brands as we always have. One caveat to the AB data, in this case the bullet changed since we last measured it, and so we’ll measure it again.

-Bryan

Nope… Berger knows how to publish accurate G7 data for their own bullets. Hornady doesn’t have a Litz so they got a doppler. You can do better Sierra!