.243 Seating depth......please help

Discussion in 'Reloading' started by JL523, Sep 10, 2009.

  1. JL523

    JL523 Member

    Jul 14, 2009
    I thought I would work up some varmint loads, so I just started loading for my .243 bolt-action rifle. I do not have a .243 Hornady Modified Case for my OAL gauge yet, so I thought I would just go off the C.O.A.L's listed in my reloading manuals. I started loading Barnes 58 gr. Varminator's last night......using information for Hornady 58 gr. V-max's (per Barnes' technical rep. suggestion). If I load to the C.O.A.L. that is listed in the manual (2.60", I believe), the bullet will not be "one caliber deep" as I have been taught. (Bullet length=0.690 - 0.243 = 0.447" + 2.035"(case) = 2.482"........well, that's how I loaded them all, give or take a few thousandths. I wouldn't have thought too much about this, but I noticed Barnes lists a minimum C.O.A.L. of 2.5" for a .243 Win. All of mine are 2.479-2.482". Will this be ok?

    I ran into a similar problem with the Nosler BT in 55 gr. I was able to get them a little longer than the minimum, but no where close to the C.O.A.L. listed in the manual. I believe my Nosler loads were right around 2.582".

    I hope I don't have to pull a bunch of bullets when I get home tonight......lol!!

  2. KDB

    KDB Well-Known Member

    Jun 26, 2009
    I wouldn't worry about it because you are using some of the shortest 6mm bullets on the market. I also use that same formula for min seating depth and have never had an issue.

    The real advantage of using a OAL indicator is when you are using bullets that are long enough to touch the lands. Then you can adjust your seating depth to jam or jump the bullet. The bulllets you are using won't get there (at least in any 243 I have loaded for).

    I usually measure off of the ogive and not the bullet's tip, as there can be a large variance from tip to tip, even in the same lot or box.

  3. johnnyk

    johnnyk Well-Known Member

    Dec 24, 2001
    For the short bullets in the .22-250 and .243 I have always used a "1/2 a caliber in the neck" approach and runout afterwards has been at a minimum. JohnnyK.
  4. txsendero

    txsendero Well-Known Member

    Nov 29, 2007
    I don't mean to threadjack, but have similar issue in my Rem 700 SPS .243Win. It has a long throat, and if I seat Berger 95 gr. VLD bullets so that .240" of the bullet is in the neck (Not including the boattail), then the bullet will be jumping .150" to the lands, and they don't shoot well at all (1-1/4" to 1-1/2" groups at best from 100 yds). Any recommendations?
  5. DazzH

    DazzH Member

    Jun 19, 2009
    I've been using the 95 VLD as a hunting projectile in my 243 and have tried them from a 10 thou jam to 130 thou jump with very little variation in accuracy.
    With .240 of bearing surface in the neck and 150 thou jump you have a lot to play with. When I had the 95's touching the lands they were held by about 70 thou in the neck, although this is far from ideal it worked. I would say just keep pulling them out further until you find the result you are after. I now use them with 30 thou jump and keep groups to around 1-3/4 inch at 400 yards.
    The rifle is off the shelf Sako 75 finnlight.
    Load is - 45 gr N160, Russian primers (I no longer use), Lapua brass, 3160fps.