Sierra 107 smk in 243 jump or jam?

Discussion in '6PPC, 6-6.5x47, 6XC, 6 Rem, 243' started by NickT, Aug 6, 2018.

  1. NickT

    NickT

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    I’ve been working up a load in my 243 with an 8 twist, and could use a little advice. Do the Sierra 107 grainers like to be jumped or jammed. So far I have worked up a powder load of 42.5 rl19 and a jump of .015 and am getting half minute accuracy. I know my gun can do a bit better. Has anyone had experience jumping then more or jamming them in 10 or 15 thou?
     
  2. #40Fan

    #40Fan

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    Mine always shot good at .020" off the lands. If you have the time and can find some, try a load work up of RE-23. I bet you'll find some lovin' around 43 grains.
     
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  3. urbanrifleman

    urbanrifleman Gold $$ Contributor

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    N160. The end.
     
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  4. Petey

    Petey Gold $$ Contributor

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    Every one of my 6mm Kriegers like a .005 or .008 jam, 4 like a .005 and one likes a .008 for the 107 SMK’s. Not sure if it’s practical with your throat or application, but it’s just the ticket for what I do. I always start on touch and found moving in works better than out. More than .008 in has always produced negative results as well. Your barrel will tell you what it likes but that’ll give you a place to start.
     
    Last edited: Aug 6, 2018
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  5. TerryPohl

    TerryPohl

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    My 8 twist likes them touching behind Varget
    Terry Pohl
     
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  6. Dgd6mm

    Dgd6mm Silver $$ Contributor

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    Nick, check out the 6mm improved and wildcat forum. In the column on the left at the very top is .243 loads. You may find some good information. You also could go to the search function and possibly find something also. I only used the 107 to fire form .243 brass into 6mm Competition Match brass.
     
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  7. swd

    swd Gold $$ Contributor

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    107's love to be in the lands. Start with the engraving marks square. They frequently shoot extremly well right there.
     
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  8. expiper

    expiper

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    most times accuracy is found with the bullet "touching" the lands,,,however I think it is more dependent on the powder charge than the bullet as to whether to jump or jam,,,Roger
     
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  9. AckleymanII

    AckleymanII Gold $$ Contributor

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    +1
     
  10. abishai

    abishai Gold $$ Contributor

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    I have always shot a healthy amount of jump with my 243 and the SMK. That grey ring that can be seen around the bullet hole in the Xring, that's the memory of where your lands used to be.
     
  11. Mark W

    Mark W Gold $$ Contributor

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    The 107 SMK load for my 243 RPR started out jumping .025. After close to 1k rounds is probably jumping a little more now but it stil shoots good so I haven’t checked it yet.
     
  12. tbeasley

    tbeasley

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    I've found 107smk to like .007 past kiss
     
  13. Raptor

    Raptor

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    Personally I think they will shoot well touching or jammed. I just shot two groups with my 6SLR at 600yds off the hood of my PU that both measured 1.8" for 5 shots and I am jumping them .045 It is a kreiger and has been set back twice. It started life as a 6BRX then re-chambered it to a 6SLR at around 2000rds then shot it for another 1000rds and pulled the barrel. It set for several years then I had it checked and the smith said it didn't have any fire cracking so I had him cut a couple of inches off the chamber end and re-chamber it to the SLR again. At 22"s its a little slow but damn it shoots good!!!
     

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