Group shapes.. what does it mean.

[johnmventers398]

3 shot groups usually work as well as 5 for me when looking for an accurate load to start tweaking . The reason most groups tend to open with 5 shots are from the shooter rushing them and not relaxing and taking the time to be consistent from shot to shot. As for variables such as ojives, neck tension, powder charge variances, etc, if small, these don't manifest themselves to be corrected at 100 yd ranges. Stretch it out to 200 -300 if possible and see if your minute of angles stay close to the same. Small variances in powder charges will start affecting accuracy as ranges increase. I can use a Lee dipper to dip powder in my 308 and get 1/2 inch groups at 100 yds all day, but when the range is extended to 200, they open up significantly from the variances in charge weights. If I carefully weigh the powder my groups stay consistent as range increases ( within my eye capability) After a certain distance loads don't matter for me because I can't see the target clearly enough to aim at the exact point each shot.
I have found that brass prep needs to be the same for a load to repeat. Everything from annealing to carbon in necks vs squeaky clean can drastically effect bullet tension.
Vertical strings usually mean velocity swings. Horzontal, with windage removed from the equation often means as the barrel heats it is making contact somewhere along the channel in the stock. Then there's the action screws.. It's not always about the load.
In short this is a very deep rabbit hole you and all of us have been down.

Thanks for the detailed information. I think what I will do is load up charges 5-7 again and possibly go up to 51 gr see if things repeat. .5 is in reality good enough for what I do. But it was the shapes that confused me.

I can stretch the range as far as I like along as it is safe. I've got 40,000 acres of land to play with.

 

[SGK]

These look like three shot groups. You are dealing with statistics. Combine all the three shot groups into one group and that is your group. Mother Nature is a bitch.

Yup

 

[Greyfox]

Are you shooting over wind flags?

Rick

 

[johnmventers398]

Are you shooting over wind flags?

Rick

Hi Rick,
No I was set up in a typical hunting set up.

 

[Greyfox]

Hi Rick,
No I was set up in a typical hunting set up.

Two comments. If it's a hunting situation you're working with 1/2 MOA is as good as you need. If you are looking for smaller groups without factoring in the wind by using wind flags, you are wasting time and components. Once in a while you may get a tiny group, but it's more likely you will get larger than the rifle is capable of. A 5 mph wind will move a .308 bullet a full bullet hole in 100 yards and you can't even see a 5 mph wind down range. Yours is an exercise in futility and you are getting load advice from people who are clueless.

Rick

 

[johnmventers398]

Two comments. If it's a hunting situation you're working with 1/2 MOA is as good as you need. If you are looking for smaller groups without factoring in the wind by using wind flags, you are wasting time and components. Once in a while you may get a tiny group, but it's more likely you will get larger than the rifle is capable of. A 5 mph wind will move a .308 bullet a full bullet hole in 100 yards and you can't even see a 5 mph wind down range. Yours is an exercise in futility and you are getting load advice from people who are clueless.

Rick

Evening Rick,

Thanks for the advice.
I went back out today and got repeated results.

I also loaded up two more charges increasing my total load by .4 grains. 51.0 was looking to be outstanding.. then before the bullet even hit the target I knew I mucked up. I yanked the trigger before the cross came to rest. Completely wasted the time and effort of loading the extra loads.

I want to say that it would have been a good group because of the previous shots, the screw up call and the following group was .29"

I take onboard what you say about shooting over flags completely. I also can't help but do things anyway just to see what happens.

I have attached pictures of my target board. It is messy cause I shot at the same one from yesterday and have doodled over it.

One piece of info I could not gather was weather or not the re testing of yesterday's loads hit the same poi.

I had to remove my file from its stock to diagnose why the bolt release was not working. . . The rear trigger pin had wiggled just about out and the spring slipped of the end of it. Good old remi eh!

What I want to do. Weather it's the proper choice or not I don't know... Is load at 51.1 and roll with that.

Thanks for taking the time to give me advice.

John.