Taken from 6mmBR.com ...
Rear Bags–Match Them to Your Stock Profile
For better accuracy and more consistent tracking, match your rear sand bag to the profile of your stock. Some stocks are curved on the bottom of the buttstock (also called the “toe”), while others have a flat, ranging from 3/8″ wide to as much as 3″. Additionally, the amount of down-angle or “drop” in a stock can vary. Traditional hunting stocks have a lot of drop, whereas a 1000-yd BR stock may have “zero drop” — meaning they are completely straight from the bottom of the grip to the buttplate.
Stocks with a flat on the bottom work best in a sandbag that has a slot between the ears. You "don’t" want the flat resting directly on the stitching–it’s better to have the bottom of the stock contacting the sides of the ears a little bit above the center seam. But you still need spacing between the ears to get the right fit–it should not be so tight as to pinch or “grab” the stock unevenly as seen in the second photo. With a more conventional round-bottomed stock, with a radiused toe, you’ll get better results from a bag with taller ears. Experiment with spacing.
Recently, Forum member Jon complained that his rifle was not tracking well, and needed to be re-positioned after every shot. Jon’s rifle has an HS Precision stock with a radius and quite a bit of drop. He was having the problem because he was using a bag with ears that were too short.
Jon will have better results with a bag with taller ears and more spacing. Rayjay explains why Jon’s rifle wasn’t tracking well: “Everytime you fire the rifle the sand in the ears gets displaced. Then when you slide the rifle forward and work the bolt, etc., the sand moves around some more. Then on the next shot it displaces again… it is not consistent shot to shot.”
Jon also had a sling swivel stud on the rear underside of his stock. Swivel studs, both front and rear, can hang up on sandbags, causing a variety of problems. Ideally, when shooting with sandbags, remove the swivel studs. If that’s not possible, at least adjust your fore-end so the front swivel stud will NOT contact the front bag at all, and adjust the rear bag so that the swivel stud is not dragging between the ears.
2 Comments »
1. Not saying that you are wrong, but I like my stock to ride on the inside of the ears with 2 places touching rather than it sitting on the bottom. Dwight Scott suggested this to me many years ago.
Butch
EDITOR: Butch–what you say make sense. Jason Baney likes to do the same thing–have the left and right “corners” of the bottom flat floating slightly above the stitching. But if the flat is of typical width these days (for a “coffin” style stock profile), one will still need greater separation between the bottoms of the ears and that’s what we intended to illustrate. Thanks for your insight!
Comment by Butch Lambert — September 20, 2007 @ 8 pm
2. Having the flat bottom of the butt resting on the flat space between the ears is almost guaranteed to give you on-target vertical. The problem stems from the different angles of the butts flat (f-r) and the angle of the flat between the bags ears (f-r). As the gun moves rearward in recoil, this relationship changes as does the point-of-contact between the butt and the flat between the ears on the bag.
Comment by Al Nyhus — September 22, 2007 @ 1 pm
I order my rear bags from Protektor with a width 1/8 inch tighter than buttstock width. Art
