OAL Length testing question.

[cornfedkiller]

When you guys are doing testing/development, how far off the lands do you start, and then how much do you change it by for your next group?

 

[Quicksilver]

I usually start .010”, most bullets I’ve shot like being there anyway so for me it’s a good starting point. Once I’ve found a powder node I’ll start jumping it in .010” increments in 3 shot groups to find where it likes to be.

 

[16Bore]

Berger has a pretty good tutorial.

 

[rodell]

If I'm shooting Barnes or Cutting Edge, I never get closer than .050", finding that shorter is usually better with the monos.

If using Accubonds, another favorite, I start at .010". I never get closer to the lands for hunting.

 

[16Bore]

Every Barnes bullet my brother and I ever loaded was seated to front of the first driving band out of the gate and never changed.

6x45, 260, 7-08, 270, 30-06, 9.3x62, 338 WM, 375 H&H.

YMMV

 

[PA Hunter]

.10 off for me except all my Barnes need a big jump.

 

[doverpack12]

I like to start 0.02” off especially with Berger hybrids because the seating depth varies drastically with my Forster dies and Berger claims you can’t measure the ogive accurately with hybrids. I haven’t needed to push any closer either. Under half Moa on multiple range sessions is when I call my loads good and 3 of my rifles are all there without burning up tons of components.

 

[Hardwoodmaterials]

I usually start at factory length and don't get closer than .010 but I'm a hunter and not a long range guy.

 

[MrTim]

.015, .030, .045
If magazine length is the limiting factor, start at max mag length and follow the same procedure.

 

[Nealm66]

I try to find the bullet manufacturers recommended coal, if I can’t , like hornady or Sierra I may use the ogive oal off a factory bullet if it is known to be accurate out of the gun I’m loading for. Be careful to start at the low end of the charge when doing the ladder test as pressure can change with seating depth. I’ve found that the same caliber in two different rifles had quite a bit of difference to the lands so that’s why I try to start with the recommended. Closer to the lands is not always better. 20 thousands or more is a common excepted hunting round in the circle I hang out with

 

[PA Hunter]

Depends on my magazine length for OAL. As far out as my mag will allow if I can touch lands back off a few thousands. Unless a Barnes bullet then I back out maybe 70 thousands jump.