6mm Creedmoor- SUBSONIC

$198.00

5 in stock (can be backordered)

SKU: 6mmCM-SUBSONIC Categories: , , ,

Description

NEW!!! SUBSONIC 6mm Creedmoor- I recently developed a 6mm Creedmoor SUBSONIC round shooting the 85 grain Sierra SP at 1040 fps in 22″ barrel. This is with new Hornady brass and  85 grain Sierra SP bullet. This bullet will stabilize in a 1:10″ twist barrel or faster (1:9″, 1:8″, 1:7″, etc). Most 6mm Creedmoor rifles have a 1:9″ or 1:8″ twist barrel, and this bullet will work very well with these twist rates.

Priced per 100 rounds

 

Why use a 85 grain SP bullet? Most 6mm barrels will have a 1:10″ twist barrel, with some having a 1:9″ twist or faster. To get a subsonic .243″ bullet to fully stabilize at subsonic speeds in a given twist rate, bullet stability becomes a huge factor for it to stabilize and shoot well. Bullet length is a major factor in how stable a bullet is in a certain twist rate. In a given 6mm twist rate (like a 1:9″ barrel twist) and slow subsonic speeds, a shorter, flat base bullet is more stable than a longer BTHP match bullet is of the same weight. The 85 grain Sierra SP flat base is a much shorter bullet than a similar weight BTHP bullet, or a 100+ grain SP or HP bullet. This allows the 85 grain SP flat base to be more stable and have the potential to be more accurate at subsonic speeds than a BTHP design that makes the bullet longer, requiring more twist rate to stabilize it. BC (ballistic coefficient) is for supersonic flight, and does not matter at subsonic speeds. Having a high BC bullet at subsonic does not benefit the shooter at all. This is why the 85 SP flat base bullets work well as subsonic round in the 6mm!