Load work up...seating depth test first OR charge weight first?

[FatOldMIHunter]

Just joined this site because this thread was so informative. I haven't read all the way through it, but I have the opposite problem of short magazine length in my 6.5X55 Swede. I can't get a bullet anywhere near the lands. The amount of bearing surface of the bullet in the neck gets to be dangerously low if I try. I just try to get a minimum of .150" bearing surface and then verify that the round chambers. I don't want to go lower in a hunting situation, so I don't test with less. In my other rifles, I will be trying the reduced load with seating depth testing first. I had heard that the optimum seating depth is independent of charge, but not vice versa

 

[Rhovee]

So basically .003 TO .005. which direction?

If .020 shot great at a lower powder charge, I would shoot groups of .006 each direction going .003 at a time cause i know i am close. With my 28 Nosler, when i ran a node close to 3000 FPS .020 off was most accurate. The picture i showed above was coming out of that node and go back into another higher node. The 3 shot group on bottom right was at .026 off. I originally stuck with .020 off and increased powder .3 grains at a time and had a flat spot in the 3050 range. This was found while shooting a ladder at .020 off but the three shots were a horizontal group. So i knew that over .9 grains had an ES of 8 but my seating depth was off a touch. The horizontal group was 1.75" at 300 yards with no vertical.

 

[Lonewolf74]

Rich that is a great example.

What really floors me is the Fed's match primer with the most consistent velocity having the second largest group size average. Just seems contradictory to what "should" happen!

 

[Lonewolf74]

If .020 shot great at a lower powder charge, I would shoot groups of .006 each direction going .003 at a time cause i know i am close. With my 28 Nosler, when i ran a node close to 3000 FPS .020 off was most accurate. The picture i showed above was coming out of that node and go back into another higher node. The 3 shot group on bottom right was at .026 off. I originally stuck with .020 off and increased powder .3 grains at a time and had a flat spot in the 3050 range. This was found while shooting a ladder at .020 off but the three shots were a horizontal group. So i knew that over .9 grains had an ES of 8 but my seating depth was off a touch. The horizontal group was 1.75" at 300 yards with no vertical.

Thanks for this info. So you have found that the rough seating depth sweet spot holds across different charge weights but you may need to fine tune a few thous one way or another once you have found the node your looking for?

 

[Tidus56]

@timberelk

 

[Tidus56]

tag

 

[Rhovee]

Yes I have found that to be correct. It can obviously make different shapes and move horizontal and vertical until it fine tuned. It's defently not as bad as group you will see when your way off your seating depth.