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Thread: bump the shoulder?

  1. #1
    vc5013
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    bump the shoulder?


    Hello I am reloading 6.5 creedmoor match ammo for tac. Precision shooting 400-1400yrds. I have been reloading my 308 ammo for a couple years. I have always neck sized with a neck sizing die once shot from my barrel. I have heard tons of people say you should size with a fls die and just bump the shoulder. I have researched and youtubed but everyone says or shows you adjust slowly until your bolt closes then measure about .002 the question I have is my bolt closes just fine with fired brass from my barrel. I have a model 10p with a shilen select match barrel and using hornady match brass.
    Last edited by vc5013; 02-16-2015 at 03:05 AM.

  2. #2
    Basic Member Robinhood's Avatar
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    Not sure where you got the .200 measurement but that is not even close. On the bright side if you bolt closes with ease you have no issues. When the time comes you can use a full length sizer or a shoulder bump die to move the shoulder back .002". You will need to measure that dimension with a tool/gauge designed for that so you have a reference.

  3. #3
    vc5013
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    But if my bolt closes with ease what is my reference point? What is my end goal and how do I know when I'm there? I've seen the hornady gauge used for this application but it seems the end goal is for the bolt to close and the gauge tells you what that measurement was for repeatability. How do I know when my shoulder is where I want it? Any help on this would be greatly appreciated.

  4. #4
    vc5013
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    Just noticed the .200, sorry meant .002.

  5. #5
    Basic Member barrel-nut's Avatar
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    bump the shoulder?

    If you are only neck sizing, and you already have several firings on your brass in your rifle, and the bolt still closes easily, then chances are your shoulder is right where you want it right now. The idea is, to have the case fill the chamber completely, but not tightly. So when your cases start to cause drag when you close the bolt, or even won't close at all, then it's time to FL resize, or at least to bump the shoulder back with something like a bushing bump die, which sizes the neck with a bushing and pushes the shoulder back without resizing the body any. I have both, and have settled on FL resizing due to case head expansion issues, which can also cause difficult chambering.
    This is where the measuring takes place. When your brass becomes difficult to chamber, measure the case's headspace with the appropriate tool. I like this one but caliper-mounted tools accomplish the same thing:
    http://www.midwayusa.com/product/574...308-winchester
    Once you have this measurement, record it. Check several similar cases for a consistent measurement. Now take your FL die and set it so that it just bumps the shoulder back, barely. Hence the .002". You will be able to measure this with the appropriate tool. Again, record this #. This is your size-to length. This will allow easy chambering again, without needlessly overworking your brass. Do this by starting with your die backed out a couple of rounds, sizing a case and measuring, turning the die in a little at a time, snugging up the lock ring each time, until you get .002 "bump" of the shoulder. Check for repeatability with a few more pieces. If you're getting a consistent .002" less than your previously recorded max length, you're good.
    Last edited by barrel-nut; 02-16-2015 at 06:16 AM.

  6. #6
    Basic Member Robinhood's Avatar
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    Good Post Barrel-Nut. Your post should make the sticky in the reloading forum.

  7. #7
    vc5013
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    Thank you very much. This is what I've been looking for for a long time.

  8. #8
    Basic Member GaCop's Avatar
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    Quote Originally Posted by barrel-nut View Post
    If you are only neck sizing, and you already have several firings on your brass in your rifle, and the bolt still closes easily, then chances are your shoulder is right where you want it right now. The idea is, to have the case fill the chamber completely, but not tightly. So when your cases start to cause drag when you close the bolt, or even won't close at all, then it's time to FL resize, or at least to bump the shoulder back with something like a bushing bump die, which sizes the neck with a bushing and pushes the shoulder back without resizing the body any. I have both, and have settled on FL resizing due to case head expansion issues, which can also cause difficult chambering.
    This is where the measuring takes place. When your brass becomes difficult to chamber, measure the case's headspace with the appropriate tool. I like this one but caliper-mounted tools accomplish the same thing:
    http://www.midwayusa.com/product/574...308-winchester
    Once you have this measurement, record it. Check several similar cases for a consistent measurement. Now take your FL die and set it so that it just bumps the shoulder back, barely. Hence the .002". You will be able to measure this with the appropriate tool. Again, record this #. This is your size-to length. This will allow easy chambering again, without needlessly overworking your brass. Do this by starting with your die backed out a couple of rounds, sizing a case and measuring, turning the die in a little at a time, snugging up the lock ring each time, until you get .002 "bump" of the shoulder. Check for repeatability with a few more pieces. If you're getting a consistent .002" less than your previously recorded max length, you're good.
    BRAVO! Well stated!

  9. #9
    Basic Member barrel-nut's Avatar
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    Thank you all. You're too kind lol

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