Berger VLD seating test

[Butte Sink]

Hello All,

Kind of a crazy question and I'm sure this is an old topic that has been addressed many of times but if any of you have a recommendation to this would be great.

I decided to give Bergers recommended VLD seat test, by seating the bullet .010, .050, .090 & .130 and the shooting 2 groups of "3" each and they state that one will shoot far better then the others. When you find which one, you then can fine tune +/- .002 to dial it in.

This is 300RUM with a 210VLD and it actually worked real well and at 310 yards I got real good results with .050. roughly
1/2" MOA but there was one flyer out of the 6 and I'm pretty sure that one was on me.
I could probably leave it where its at and have good results, custom build I use for hunting but I want to see what it can do.
Question I have is how would you approach this, call .050 middle ground? and then go both ways and if so, how far would you go each way?
Again being 300 RUM barrel life is short

Thanks!!

 

[Jeff Porter]

How much better was 0.050” than the others ? In my experience with other Berger jump tests I get most in the .75-1.5 moa then one snugs up at 0.5 or better. My typical action plan would be to repeat the test with 5 shot group at the 0.050” jump and another 5 0.005” either side if that. If it is still at 0.5 or better I would call it done for a hunting rig in that caliber. Since you are hunting you may want to let the barrel cool all the way down between shots too so you get 5 first shots.

 

[Butte Sink]

Perfect Thanks
Exactly what the others showed as you said.

That sounds like a plan!!

 

[mikecr]

Did you back off the load for testing, or test from some powder node?

If you've found a good coarse seating (sounds like you may have), then do powder development with that, then fine tweak seating in it's window for tightest group shaping.
Seating windows are typically 8-10thou wide for long ogives.

 

[Butte Sink]

Thanks
Took it from a powder node
N570- 93.0 -96.3 and getting good results at 94.6 / 3185 +\-
Going to stick with it and fine tune seating and see what I can get.

 

[HSMITHTX]

I'd go +/- 5 and 10 thousandths, see which direction it likes. If that isn't conclusive do another set 15 and 20 thousandths plus and minus. I want to find the longest load that still shoots well and the shortest load that shoots well, then I can load and shoot for a good while without having to find the jump that it likes. If I find a window that is 20 thousandths long I can load at the long end of that and throat erosion is bringing me back toward the middle and eventually to the end of the window. Even a RUM run hard you can get quite a few rounds out of 20 thou before you have to do anything. I like shooting, load development is a necessary evil.