Seating Depth for Sierra 155-2156 Palma Bullet

[ehampel]

My first set of test loads with the 2156 Palma bullet was less than great. I used Varget from 44-46 grains, Fed 210M, LC 77 Match cases at magazine length - 2.80 inch. (29 inch Obermyer barrel 308). These bullets are more VLD shaped than the original 155's. The best success I have had with any VLD bullet was seating depth well into the lands. Any thoughts on the best way to go? Any experience with seating these 155's into the lands?

 

[ftrrookie]

My rifle likes them set at .024" off the lands.

 

[skiutah02]

Maybe this helps. I did this early in my load development just to see. I jumped from 5 to 50 thou and saw very little difference. 1st pic is 5, 10 ,20, and 25 jump (hopefully clear) at 100 yds day two of my load development. My 5 thou jump was slightly better than others and 40 thou was also a contender, so I compared 0.005"" jump to 0.040" jump at 300 yds (pics). Ultimately I am using 0.040" jump because at 0.005 " jump the bullet is barely hanging in the neck of the case and as my throat erodes, I will have problems.

As always, this is in MY rifle so be sure to test in YOUR rifle since YMMV. Drew

 

[MNFinn]

.020 Jump has worked the best for me

 

[watercam]

I have three barrels. Two don't really care as long as they are jumped from .015" - .030". The last one likes them right at .010" off the lands. Interestingly enough those barrels like the Berger Fullbores jumped the same amount.
The two barrels that are more forgiving are Bartleins, the third is a Krieger tight bore.

 

[FilippoMo]

We got much better results after selecting bullets from base to ogive we seat in the lands.
Filippo

 

[NickB1075]

My rifles all like the 2156 jumped when I tried jam the groups got horrible. I have found that the bullet is fairly easy to tune. A friend of mine jumps his at .030 to .040. And shoots cleans at 1k regularly.

Nick

 

[wolley]

With a tight throated chamber. .3085" or less they will shoot at any distance off the lands.
Big throat may require a light kiss of the lands.
I shoot em .015" out.

 

[ehampel]

Thanks for the feedback. The consensus seems to be some amount of jump to the lands is desirable.

I'll try to work with that.