What makes reloading more accurate

[DRC458]

You must tailor the load for that specific barrel, receiver and stock combination, then be consistent in putting it all together. As Dennis said, that can vary with temperature and altitude, depending on what powder you use. Sometimes, a tenth of grain can make a big difference. I have some rifles that will group about an inch, then shrink to half that with a tenth of a grain adjustment ... be that up or down. It's not tied directly to velocity or pressure. Just like people, every rifle is different.

 

[swampratt]

I will add this on consistency. I agree with all the above, but something that will make your groups not as accurate is the way you hold the rifle.

If you put your cheek in a different spot or if you put the front or rear rest in a different spot you can change where the bullet lands.

Placing your thumb on the barrel during a shot can pull the shot, make it look like you got an unexplained flier from the load.

I used to shoot from a homemade rest that held the front of the gun and held the butt like the lead sled type rest.
I found that when I shot with no rest the bullets did not group the same and point of impact shifted.

So I no longer use that rest because it does not duplicate what happens in the field when hunting.

So be very consistent in where you place the bags or how you hold the gun.

 

[furlong222]

you are on the right track....work up an accurate load powder/bullet/brass/primer combination and repeat....if you change anything you will most likely get a different point of impact - sometimes its minute and some times its a significant change....write the good recipes down....your rifle will tell you what it likes....

 

[Blitzfike]

So pretty much it's working up the loads until the gun likes it and then staying in that zone.

Yep, That's it in a nutshell

 

[Jcann]

To stay in that zone you need to buy your components in bulk (8 or more lbs of powder, 1,000 or more primers, 500 or more bullets all with the same lot number). I've had as much as 90fps drop in muzzle velocity due to different lots of the same powder. I've also found that case annealing should be done every 3rd loading due to case harding the brass through repeated loadings. This effects bullet tension which effects chamber pressure. Granted I'm shooting a round with ~65,000 psi.

If you're shooting a barrel burner like a 243, 6.5x284, or 7mm mag you'll probably notice velocity and accuracy degradation between 800-1,200 rounds due to throat erosion depending on how hot your running your loads. You may be able to alleviate this some what by chasing the lands by seating your bullets further out but this is dependent on magazine COAL.

Be mindful that sometimes you feel like you're chasing your tail in the hand loading arena.

 

[Pulp]

While I agree with all of the above, there is one other factor. Factory ammo is made to fit everyone's rifle. Handloads are made to fit your rifle. Example: you buy the first rifle made with a new chamber cutter. Your chamber is going to be a mite bit larger than the next ones, as the cutters wear down, the chambers get tighter. They are still in SAMMI spec, but each chamber is slightly different than the last on bored. Factory ammo is going to be a loose fit in your chamber. Now by loose, I don't mean a 1/2 inch of slop, were talking very tiny numbers, but the difference is there. Your brass will be fireformed for your rifle. By neck sizing only, you'll have a tight fitting cartridge for your rifle. That's less movement in the chamber, less the brass expands on firing. You've just removed two variables from the equation. Of course, there are still a gazillion other variables you have to deal with, that's what makes it fun. Or frustrating.