Help read OCW results

[coyotezapper]

My impression of OCW was that you look for a string of consistent group centers not just vertical consistency.

Its not a OCW so don't get them confused. Do one or the other. This method look at vertical only - not group size. Pick two that are vertically the same and then go to the middle between the two and start working seating depth. The two you pick have to be next to each other i.e. 60 @ 60.5 grains and are in the same vertical in POI. This method will make it so you will not have to chase lands, or not as much.

 

[bill123]

Its not a OCW so don't get them confused. Do one or the other. This method look at vertical only - not group size. Pick two that are vertically the same and then go to the middle between the two and start working seating depth. The two you pick have to be next to each other i.e. 60 @ 60.5 grains and are in the same vertical in POI. This method will make it so you will not have to chase lands, or not as much.

I guess where I'm confused is that the method that you linked to looks like ladder testing but shooting groups at 100 yds instead of single shots at longer distance.

 

[Bigeclipse]

Its not a OCW so don't get them confused. Do one or the other. This method look at vertical only - not group size. Pick two that are vertically the same and then go to the middle between the two and start working seating depth. The two you pick have to be next to each other i.e. 60 @ 60.5 grains and are in the same vertical in POI. This method will make it so you will not have to chase lands, or not as much.

So by this which two do you think I might look at?

 

[Kiwi58]

Hi Guys
I have just got into Long range hunting after many years of working as a government hunter in Newzealand.

I have purchased a new Tikka T3x hunter in 270win which I am in the process of developing handloads for.
I will be shooting out to 500 yards on Himalayan Thar in the rugged southern alps in NewZealand.
What are your good folks views on the nodes of my OCW tes below?
Cheers
Vaughan

 

[coyotezapper]

Hi Guys
I have just got into Long range hunting after many years of working as a government hunter in Newzealand.

I have purchased a new Tikka T3x hunter in 270win which I am in the process of developing handloads for.
I will be shooting out to 500 yards on Himalayan Thar in the rugged southern alps in NewZealand.
What are your good folks views on the nodes of my OCW tes below?
Cheers
Vaughan

Do you have any velocities to go with the targets??? You can't determine OCW without velocities.

 

[Kiwi58]

Do you have any velocities to go with the targets??? You can't determine OCW without velocities.

yeah they are printed in pencil on the targets.
The best I could get was 2780 fps out of the 52.8 grains

 

[WildRose]

Hi Guys
I have just got into Long range hunting after many years of working as a government hunter in Newzealand.

I have purchased a new Tikka T3x hunter in 270win which I am in the process of developing handloads for.
I will be shooting out to 500 yards on Himalayan Thar in the rugged southern alps in NewZealand.
What are your good folks views on the nodes of my OCW tes below?
Cheers
Vaughan

Your best groups to me are 9 & 10. If it were me I might try just tweaking seating depth from there and see if it improves any more. Keep in mind that the closer you get to the lans the quicker the pressure will spike.

 

[coyotezapper]

yeah they are printed in pencil on the targets.
The best I could get was 2780 fps out of the 52.8 grains

Even when I open the targets in another window there are some that the velocities can't be seen. As far as OCW, what you are looking for is a minimal velocity increase from one powder charge to the next. For example if you are only seeing a 10 fps increase from one half grain increase compared to say a 50 fps increase then this is what is considered OCW, powder node or flat spot, whatever you want to call it. Its in this area where you want to do your seating depth testing.

Groups 9 and 10 look ok also and could be tightened up with seating depth testing but because of the difference in velocity between the two, the powder node will be very narrow. I like to have a minimum of a half grain window which allows me to have a good load longer without having to a change charge weight and seating depth as often.

 

[coyotezapper]

Hi Guys
I have just got into Long range hunting after many years of working as a government hunter in Newzealand.

I have purchased a new Tikka T3x hunter in 270win which I am in the process of developing handloads for.
I will be shooting out to 500 yards on Himalayan Thar in the rugged southern alps in NewZealand.
What are your good folks views on the nodes of my OCW tes below?
Cheers
Vaughan

What's your barrel length and the powder and bullet you are using?