Once fired brass what happend?

[BoydAllen]

Back in the day when I first tried it, I tried it both ways on .22-250 cases, and looked at the results with a concentricity gauge. Necks first had a slight edge. I suggest that you do your own testing.

 

[AZHunter12]

Use case data wins. Thanks, Boyd.

 

[Nomad47]

The OP said he fire formed 243 brass. To what? 243AI? Or 6CM?

 

[dkhunt14]

The OP said he fire formed 243 brass. To what? 243AI? Or 6CM?

I believe to 243. I don't believe their is enough of a capacity change to make that much difference in volume. Matt

 

[Drop Port]

Fire formed new brass 243 win 28in PAC NOR barrel samii min chamber 1in7 twist shot great ,hit golf balls at 300 till got tied of hits. Reloaded brass neck size only ,105 nosler C.C. 4831sc 43.5gr cronod at 2958 aveg. Shot like I had a bent barrel, look like a shotgun blast ,same mount same everything,temperature was lower by 30 degree ,barrel has only 150 rounds on it so not shot out any thoughts? Winchester brass, trimmed and sized before first firing./

And I wonder, If you were hitting golf balls at 200 yards what did you have to gain by changing anything? If your cases were minimum length/full length sized I believe that would be a good place to start.

Then there are factors that change when going from fire formed to neck sized.

F. Guffey

+1 why speculate on powders and other factors. Go back to what worked in the first place and duplicated it, to include same neck tension.

 

[lbran]

like 243winxb said, your case volume change! try bumping your shoulder 2 or three thousands and I bet your groups come back!

 

[scott_at_vortex]

OP,
Are you saying the barrel has 150rds total?

If so, that is about when new barrels start to speed up.So if your original load happened to be close to the edge of the node or it was just a narrow node this would cause that load to be out of tune now. I would try dropping your charge .5-1.0 grains and see what happens.