Sometime in the past, I did a test on the effects of seating depths on accuracy, and frankly, saw very little difference.

I used match bullets.

Some members have been saying they get better accuracy with mono bullets if there is a jump to the rifling.

This jump seems to vary according to the source.

I am running an experiment to see what the results are.

Rifle is a Kimber 8400 PATROL TACTICAL HB.

Bullets are original BARNES 180 XBT.

Load is 36.0 VVN 540.

I just looked in the book, and added the minimum recommended charge to the maximum and divided by two.

Started off with cartridges loaded to 2.800 inch, which the maximum for the 308 Winchester.

1. 0.596
2. 1.233
3. 1.058
4. 1.250
5. 0.985

Average 1.0244

2.770"

1. 1.611
2. 0.741
3. 1.426
4. 1.428
5. 1.167

Average 1.2746 inch.

I will continue shooting with each increment 0.030 shorter.

Have fun guessing the results.

I will post all targets once I am done.

The rifle does foul quite a lot.

I am cleaning the barrel between each batch.

Comparing one rifle to another is just nuts. There are too many variables to consider. How long is the lead? What type of rifling? Where is the origin of the rifling? Bore size? Brass used and trim length? And on and on.
I do crimp. Not crush. A measured pull of 18 pounds is used. This way, all rounds fired have the same force needed to get the bullet moving out of the case. All I shoot is long range and my loads have won many matches. I load as per the specifications of the cartridge design. This being all bullets will jump into the rifling.
Thanks for your data. Obtaining ballistic data is fun.