Originally Posted by
Ridge Runner
a bullet your rifle likes is the main thing to accuracy, the little things like seating depth, neck tension and the like will improve them. also the bullet exiting the muzzle at a consistant velocity helps also, how do you do this, use a slower for capacity burn rate (not the slowest your velocity will be down) powder that peaks in pressure in your chamber after the bullet enguages the rifleing, this keeps the velocity even and a smooth buildup to peak pressure which will cause the bullet to exit the barrel at the same place in the harmonic travel of the barrel every shot. find this sweet spot and it will be as good as your rifle is capable of.
RR
All good advice but I'll add a few things to it.
When you get new brass, spend a few minutes making it uniform. Often the brass will not be square across the mouth and the walls of the mouth may not be uniform all the way around. When I get new brass I lube it and run it through a full length sizing die and then I trim it 1/1000th less than the max recommended brass length. That gives me some leeway as the brass will stretch as it is shot and resized. I also turn the mouth so the walls are uniform. That way as the bullet is released from the brass the tension is the same all the way around. There are several brands that make sizing and turning eqpt. I happen to like Foster.
After I have the brass prepped I load a minimum load with cheap bulk bullets and fireform the cases to my chamber. From then on, all I do is neck size the brass and trim it as it stretches. Brass last a lot longer if you limit the amount of time you full length size it.
Also, often a max powder load isn't the most accurate load. The whole point of reloading for me is accuracy so I usually don't max it out. One thing that can make a big difference is primers. In my 7mm Mag it is Federal Mag Rifle primers. CCI, Rem and Win don't produce the same accuracy as the Federals do. I believe it has to do with Federal being a "hotter" primer and giving more even burning to the powder. Another thing that can make a big difference is seating the bullet to the right depth. On the above 7mm if the bullet is just barely touching the rifling, it is spooky accurate. Seat the bullet a little deeper and the group opens up. This is because the bullet has to "jump" forward before it engages the rifling. The further the distance the more likely the bullet will not be perfectly centered in the bore.
Sometimes the little things can make a big difference.