Throat + jump?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by 300WSMMAD, Jan 24, 2009.

  1. 300WSMMAD

    300WSMMAD Well-Known Member

    May 19, 2008
    Ive been told that on big magnums like 338 Lapua, 338 Edge etc it is very important that they have large jumps, up tp 250 thou is ok!
    Its to do with the massive pressures involved.
    Even on The defensive edge website in the load data is states throat+50 thou.
    This worries me slightly because load info I was given 10 thou off lans for my 338 LM.

    Can any one shed any light on this please

    Thanks in advance

  2. davewilson

    davewilson Well-Known Member

    Feb 19, 2004
    for me personally, the first rounds i put out of a barrel, which are the break in rounds, i have the bullets at least .050 off the lands with a very low charge of powder. i don't care what cartridge it is. as you break the barrel in you get a feel for the pressure in your gun and slowly walk the powder charge up.

    as far as a big jump being "needed" that is just not the case. what i have heard a couple very experienced 338 shooters tell me is that not only will i get better accuracy, but my spreads will be lower jumping the bullet a little. with my gun that seems to be the case. i load mine about .050 off the lands.