How do I "tune" a load to be more accurate?
Tuesday, May 10, 2005 (23:48:13)

Posted by DallanC

Each rifle is different and will usually like a specific load “recipe” to achieve best performance. There are several things which can be done to enhance accuracy of a load for a specific rifle. The following are tips in no particular order.

#1) Try altering the amount of powder used in the load. Move up from the minimum recommended load in your reloading manual in .5 grain increments until you either notice excess pressure signs OR you reach the maximum recommended load, which ever comes first.

#2) Try changing powders to a type of powder which will fill the case more. Most rifles like powder charges which fill the case 80% or more.

#3) Try adjusting the seating depth of the bullet. Most rifles will like the bullet a few thousands of an inch off the lands. This usually requires a Cartridge headspace gauge to measure but can be done by denting an empty, sized case mouth slightly and lightly inserting a bullet. Chamber the empty case slowly, letting the bolt act as a press and the rifling to seat the bullet into the case. Take an Gage OAL measurement of this case length and seat the bullet a few thousands more. Barnes X bullets usually like more freebore to the lands so try seating them deeper. *Note: when altering the seating depth of a cartridge, reduce the load slightly as the volume within the case is also altered as the bullet is seated at different depths.

#4) Get a primer pocket uniformer tool and make sure your primer pockets are uniform. When most brass is created, a small burr is left inside the case and can make for a non-uniform burn of the powder.

#5) Try different brands of bullets and even bullet weights. Some rifles are picky as to what weight of bullet they will shoot well. This can depend on the twist of the barrel rifling.