Ladder test 7RM Upacreek

[upacreek]

Forgive me for being a little green here, but I wanted to share my findings and start to document so progression. I picked up my rebarreled action last spring and have just gotten around to load development. They way i was taught to reload was load as hot as the primer indicated you could and back powder down to pick up accuracy. The last couple years readin this forum has made me almost relearn everything about reloading.
I have new cases for this rifle but got cheap and used my old winchester brass for load development. Today it caused an issue, more on that later. After sizing my brass and sorting 10 peices out that were same weight, same length at the shoulder and all respects identical I loaded bullets .002" off the lands (cause i am chicken) from 66.5grains to 71grains of Magpro. My chonograph is old but reads 69gr at 3080 to 3100fps consistently.
I have a place half a mile from my house that i could shoot 2000 yrds if you could deal with the badger holes so I set up a target at 400yrds. My scope is a 22x44 vortex with fine cross hairs. Hind sight is that i should have brought sand bags because off bipods the best I could do was to wobble the crosshairs about the 1" the bulls eye was round. It was the best i could do.....
My first shot was higher than expected and a little right so i opted to make an adjustment of 4 clicks (1moa) down and 2 clicks (1/2moa ) left. The rest of the shots were at the same elevation and windage adjustment. There was a 3mph wind coming at me from about 70 or 80 degrees, but basically in my face.
Shots 67.5 through 69 did exactly as expected. Then I got lazy and chose not to walk the 400 yrds to the target so after shooting 2 shots and finding them both below the 69gr hole I have no way to know which was which.
The 70.5 hole was generated by old brass that i have no clue how many times its been reloaded. Upon ejecting the brass the neck was found to be cracked lengthwise. My next reloading step to learn is annealing my brass........
Since 71 landed close to 69 and 68.5 I hope my node is 69 through 71. The case loaded at 71 had the only weird bold feel. No ejector mark, but felt marginally stiffer to lift the bolt.
So at the end of the day the gun shot 4 holes (68.5, 69, 69.5 or 70, and 71) in a 3" wide by 1 3/4" tall group. The other 69.5 or 70 unknown hole makes it 4.5" wide and 2.5" verticle.
These were at 400 yrds and i really expected a better spread than this. So what would you guys do at this point? What should my next step be?

 

[upacreek]

Here is a picture.

 

[upacreek]

Just a curious side note. While doing barrel break in I was really discouraged at the poor performance of this gun. My groups at 100yrds averaged 2 to 2 1/2". When I asked my gunsmith about this he told me to quit wasting ammo at 100yrds. So when moved to 200yrds the groups averaged 3/4" to 2" depending on load. So I am shocked how well this 400 yard group is! Never would have expected it. Cant explain it.

 

[den]

looks to me like had you not adjusted your scope the first two would have been real close together with the third not having any vertical out of the three shot group it would have made it is hard to tell from a picture, I would measure the distance down and left relative to the adjustments you made and see if they would have been close

 

[upacreek]

Went to do a ladder test on H1000 tonight. Had 4 of 5 shots within 1/2" verticle and a flier that made the 5 shots 2" verticle at 400yrds. Since my chonograph battery died it was a pretty disappointing night. I did shoot 3 shots of 70gr magpro tonight and was very pleased it grouped 2 1/2" at 400yrds. That is good considering i have shot about 20 rounds every night the last week and my shoulder was killing me. The best i could do was 1 to 1 1/2" orbit around the bulls eye. So a 2 1/2" group is something i can live with.

As a side note the stiffest load in H1000 was 71gr with a 162sst. It chonographed 3200fps just before the battery finally died. Could that be right? No pressure signs or flat primers either. Any input or experience like this?

Thanks.