Sierra Heavy TMK 6MM Testing

[Formidilosus]

Honestly, any decent 6mm projectile does that in a Dasher over 30 grains of Varget!

That was the point.

 

[jjohnsonElknewbie]

Weatherby's long freebore came from necessity more than anything. Roy was a true believer in ballistic superiority and that speed killed. The problem in that day and age was that the cases and actions that were available couldn't contain the pressure he needed to create the fastest 30 cal magnum on the market. He achieved the extra speed by lengthening the feebore, which essentially changes the pressure curve, and allowed him to pump the velocities much higher than any other cartridge that was commercially available.

With that said, you have always been able to achieve some impressive accuracy without seating at or into the lands. Other cartridges also had long, long, long throats like the 6.5x55 and the 7x57 to name a couple. Some of these cartridges also could shoot accurately, but maybe not to the same level they could if you could have reached close to the lands with a bullet.

That's where todays new cartridges really do shine. So many guys poo poo them because the cartridges they know and have loved accomplish similar goals. And honestly, in a lot of ways they do. The big thing that's different though is the fact that all these modern cases have much less need of being able to touch the lands to create top end accuracy. The case dimensions, shoulder angle, and especially the freebore clearance (distance on either side of the bullet as it transitions from the case to the lands) all lend themselves to allow for bullets to engrave straight into the bore, which in turn delivers very good accuracy without the type of gyrations we used to have to go through to see cartridges perform.

Thank you for the information in this and previous posts. It just reinforces my love for my black sharpie and "crude" and "caveman" seating depth process. I use the same process for 7-08, 25-284, and 6.5 WSM, with every different bullet, and the result is always the same- excellent accuracy without any extra tools or fuss.