The few I've shot through 1/7 and 1/8 barrels grouped wonderfully.
I wrote for Varmint Hunter Magazine for 14 years and was their senior technical writer. I was in on the Nosler 40Ballistic from the beginning.
Gail Root, who was Nosler's Ballistician, developed the 40Ballistic and he loved the bullet. Strangely, the ballistic coefficient came out considerably higher than the "Army Program" calculated it. After a few years, we settled at a BC of .221, but I swear that in field shooting, it looks more like .260.
The wind drift of the 40Ballistic is often less than calculated ... another vote for a higher BC.
I've probably shot 50,000 or more 40Ballistics in the field and they are unreal on prairie dogs and fabulous on big coyotes. And they really cream bobcats and badgers.
Yep, I've whacked a couple of mule deer with the 40s, too. Worked perfectly.
My go-to bullet in the .223 Remington and .223 Ackley is the 40Ballistic.
God Bless,
Steve