6.5-284 coal question

Discussion in 'Reloading' started by Gray R, Oct 23, 2013.

  1. Gray R

    Gray R Well-Known Member

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    Hey everybody I just got my rifle rebarreled from 308 to 6.5-284 and got set up to load. First I just want to say this is my road huntin rig so shots should be about 500 or less and I am NOT using the rifle competitively. Now my question is I loaded some 130 gr vlds to a length of 3.10 and when I chambered the round to check it(habit I developed so I don't make it to the range and have rounds that won't chamber) I got some resistance but the bolt still closed. I measured it and it was down to 3.03 overall length. Is that normal or is there something funky goin on? I ask cause I'm relatively new to reloading and brand new to this caliber plus can always learn something. Thanks ahead for the responses.
     
  2. BrentM

    BrentM Well-Known Member

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    3.10 sounds like the bullet might be entering the lands and is being pushed back into the case. Based on these numbers the bullet is entering the lands .07 before the case is fulling inserted and bolt locked. I can not imagine any other reason for this occurance. My guess, let me know, is that after you chamber and cycle the bolt, the second cycle of the bolt you don't experience this bolt resistance.

    I don't know what book you used to develop the load but I would double check the numbers. Bullet types, weights, etc have to all be measured properly to ensure the correct seating depth is acheived. Two bad things that happen is high chamber pressure and the possibilty the bullet gets stuck in the lands when you try to remove the unfired cartridge. Now you have stuck bullet and powder all over inside your action.
     

  3. Creedmoor shooter

    Creedmoor shooter Well-Known Member

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    I have to agree with brent. It sounds like your bullet is entering the lands. Look at the tip of the bullet, you should see some marking on it if it is. Or at least thats been my experience. Had this happen to me lots of times. Just check your oal.
     
  4. BrentM

    BrentM Well-Known Member

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    Good point OAL vs COAL. OAL is the OGIVE to case base length. This is the only true measurement that is meaningful for your specific rifle and bullet. COAL is what the testers used while writing a book. With a 140 VLD my COAL is 3.15 but my OAL is 2.482. This is .100 off the lands. 2.582 OAL is the bullet touching the lands. If I switch to the 160 Matrix I my OAL 2.508 for a seating depth .100 off the lands. So 2.482 vs 2.508 with different weights of bullets. Here is a weird one..... 140 SMK has the exact same OAL as the 160 Matrix.
     
  5. Gray R

    Gray R Well-Known Member

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    We'll I removed the cartridges with no problems thank god. Powder is too hard to come by to be pouring it in my action. And I figured it was touching the lands I just didn't think it would be maxed out that short. Thanks for the advice guys
     
  6. roninflag

    roninflag Well-Known Member

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    i use a hornady comparator with a modified 6.5-284 case. . they are not that expensive. and i load .030 off the lands for hunting and .010 off the lands for matches.
     
  7. moto450

    moto450 Active Member

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    Where did you find your Hornady modified case? I can't seem to find one anywhere

    Thanks
     
  8. BrentM

    BrentM Well-Known Member

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    I have the same case. At the time I ordered it off midway. You can make your own too. Just have drill and tap.
     
  9. Mikecr

    Mikecr Well-Known Member

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    Cartridge base to ogive(CBTO)
    Cartridge OAL(COAL).

    Gray R, I don't know why you chose the COAL that jammed, but you may be finding that it's not a good practice to blindly follow books here. And you should not have charged ammo until working this out.
    There are a bunch of methods used to find max length, and you can search them here for sure.
    With your new finished barrel you should 1st make an uncharged dummy round at max length for every different bullet you intend to use. You measure this with your chosen tool for CBTO and log the info as a reference.
    Commit to using the same measuring tools/methods forevermore, because this is YOUR standard(better than any other). Now when you want bullets ~10thou off lands for example, maybe because your barrel shoots best there, you just make your ammo 10thou shorter -as measured your way.
    Important is that you can repeat it for every round you make.