Seat into the lands or "jump"?

Discussion in 'Reloading' started by Alucard, Jun 23, 2008.

  1. Alucard

    Alucard Well-Known Member

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    Hey Guys,

    I am starting to play around with seating depths in most of my rifles. The question is, which shoots better: seating into the lands by say 0.005" or "jumping" the bullet to the lands?

    If seating into the lands, typically how far should one be going? If "jumping", once again, about how far should one be going? I am looking for what gives the best accuracy. Thanks for the help!
     
  2. .280Rem

    .280Rem Well-Known Member

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    Lots of schools of thought here. Mine is if the magazine allows it, I seat in to the lands. Just touching. I figure if it wont shoot that way, I can't figure how it will not touching, but I know a lot of guys that develope their loads playing with seating depth too. No wrong way, and ultimately, your gun, and only your gun will tell you the answer for you and your gun.
     

  3. Jim/Iowa

    Jim/Iowa Member

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    I usually seat at .010 off. I noticed a thread on another board about a shooter having great luck in accuracy with a 100 g hornady bullet in a 7mm mag. I tried it in my Ruger 77. Using the formula that the bullet must be seated a min of its diameter, this load worked out to .26+inches in jump. 5 shot groups were less than 1". I would say it depends on??? That is a way better group than I get with any loads off the bench with this rifle.
    Jim
     
  4. Gene

    Gene Well-Known Member

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    It really boils down to what your rifle likes. Some shoot best with 5-10 thou jump. Others with that much or more jam. You need to experiment. Seat .005 difference at a time. In general, VLD's shoot better with jam. I shoot 80 gr. Berger VLD's in my competition .223 and it likes .020 jam.
     
  5. BHP9

    BHP9 Well-Known Member

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    I'm with Gene on the first part.

    Can't say about VLD's - yet.

    My .308 Remington can be seated out to 2.942", forget about using the mag.

    I tried everything but load to 2.80" OAL because the best accuracy came from that and 0.020" off the lands.
     
  6. Lightvarmint

    Lightvarmint Guest

    YOu can tune your gun to shoot with a little jump. It sure makes it easier to finesse into the magazine and to get loaded rounds out. All mine jump. I quit shoot in the lands when I had one come apart on an expensive hunt.

    Got them all tuned with at least .020 jump and some as much as .060. They all will shoot bug holes as well.

    James
     
  7. Reloader

    Reloader Well-Known Member

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    May 27, 2004
    It depends...

    It depends on the rifle. I've loaded for several that it just didn't matter. For hunting ammo, I like them just off the lands to keep from having any mishaps in the field. The mag length kills many hunting rifles. One reason I prefer 700 LAs.

    If you are just punching paper try several and see what proves best, but for your hunting rigs, you may want to have alittle "jump."

    Good Luck

    Reloader
     
  8. Alucard

    Alucard Well-Known Member

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    Ok, thanks for the help guys! Hopefully I will have some time to experiment this weekend.
     
  9. kfrye

    kfrye Well-Known Member

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    I am working on this issue with my 338 RUM. Mag length creates a long 'jump', but I have 200 grain Ballistic Tips and 225 Accubonds down to 1/2 MOA with a poor rest and seated to work in the magazine. I think they have a potential for one ragged hole group if I can do my part holding it still. BTW, the rifle is a Sendero accurized by Bob Hart, it didn't come shooting that well.