THE HANDLOADING BENCH
308 Winchester Rides Again Part 4 By Laurie Holland
The 200gn Sierra MK is a bargain compared to the other ‘heavies’ especially if bought as a 500-bullet box.
140gn match bullets often produce bug-hole groups when so loaded in the .308W based .260 Remington for magazine operation.)
Anyway, the way to get the set-up we want is to increase the amount of ‘freebore’ between the end of the case and start of the rifling lands, ‘throat the chamber long’ to use the vernacular. The downside of this practice is that while lighter (155-175gn) bullets can still be used, they’ll likely sit well short of the rifling even when barely seated into the case-neck. That may or may not affect their grouping performance but it will almost certainly incur a substantial MV penalty.
Actually, it’s surprising how much jump some bullets will take and still produce small groups. I had a new barrel put onto my .308W Barnard/Eliseo tubegun over the winter and the replacement has been throated for 208gn Hornadys/210gn Bergers, whilst its predecessor had been chambered for 155 to 185gn bullets - around 0.110 inches more ‘freebore’ on the new set-up. I fired some leftover 155gn BJD- HBC bulleted rounds through this barrel expecting large groups as they’re making a 0.120-0.130 inch jump into the leade. Despite the bullet having an aggressive secant nose form (VLD type), six rounds promptly went into 0.4 inches at 100 yards – no load development, no messing!
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