How far off the lands ?

[Bluejay]

I am building up a target load for my 6,5x57R, using Lapua 139 grs. Scenar bullets.

How far do you suggest I keep the bullet off the lands to start ? My barrel twist rate is 1:8"

Thanks
:wink:

 

[DrMike]

You should be able to load out to the lands with that bullet. Everything else being equal, I tend to load close.

 

[Bluejay]

You should be able to load out to the lands with that bullet. Everything else being equal, I tend to load close.

Touching then...? :mrgreen:

I would like to get an overall length that goes well with powder density inside the case, even though not looking for a load too hot, so the more the bullet's out......the more powder's in..... :mrgreen:

:wink:

 

[DrMike]

I would start 0.010 off the lands and test at 0.005 increments closer and away once I found a load that provides good standard deviation. The problem with loading to the lands is the possibility of pulling a bullet and dumping powder should you need to remove a chambered cartridge at some point. For my own rifles, most cup and core bullets work best between 0.010 and 0.020 inches off the lands. Monolithic bullets are in a different league (though the jury is still out on the GMX).

 

[rick smith]

Fit the mag box, if you have one, and not be into the lands. I usually start 10-15 off the lands and work with the powder. If nothing looks good I change powders. I use seating depth and primer change as fine tuning tools.Rick.

 

[DrMike]

I made the assumption, perhaps wrongly, that since it was a 6.5 X 57R, that this rifle was either a drilling or a single shot, in which case loading to the lands makes perfect sense. However, if it has a magazine, Rick would be correct.