Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Newbie Needs Help Sizing!
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="boomtube" data-source="post: 449316" data-attributes="member: 9215"><p>gunaddict62791 your questions are valid and some of the reasons for confusion are posted here. Fact is, Mr. Willis is fully correct about using a gage to get it right.</p><p> </p><p>But first you should know that "cam over" applies only to the press, not the dies or cartridge. All it means is that the lever and toggle has pushed the ram fully up and started back down a tad, "cammed over". It has no more meaning than for a press that comes to a full stop at top dead center and moves no further. Where the die is in that movement is the critical part and that is up to the user.</p><p> </p><p>Now, for very good accuracy, good case life and slick chambering, it's commonly considered to be better to FL size for sporting rifles each time. But, it IS best done with the minimum amount of working the case shoulder. A case shoulder gage (such as Mr. Willis sells - Goggle "Innovative Technologies", or the Hornady, Sinclair or RCBS tools) lets us actually measure where the shoulder of a fired case is. It CANNOT be done by eye or even feel, we must have a gage that measures to the thousant the distance from the case head to the shoulder. (Exactly where we measure to on a shoulder is irrelivant, the entire shoulder is equally usable for comparitive measuring! <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /> )</p><p> </p><p>Somber instructions to adjust a sizer to touch the shell holder plus another magic 1/4 turn, etc, is silly. That presumes every press has the same amount of spring and slack in the lever linkages, every die has exactly the same inside diameter and internal length and every case will give exactly the same resistance to sizing. That's obviously not true. We must find what our combination actually requires, not follow some specific method that only gets most people in the right ball park.</p><p> </p><p>So, how much to "set shoulders back"? Well, why set then back at all? A fired case has expanded to the fit the chamber and sprung back a tad already, it will easily re-chamber just as it is. </p><p> </p><p>Therefore, why not simply set the FL sized shoulder back so the longest sized case is no longer than it was to start with? That will be fine, let the shorter ones fall where they will. I said adjust for the "longest" fired and resized case because individuals WILL vary some 2-3 thou both after firing <u>and</u> after sizing; it's a fact of life that cases are NOT totally uniform in how they springback! Even seemingly trivial things as how hard you press on the lever, how long you hold the pressure, and how much of what type of case lube you use will make small sizing differences too!</p><p> </p><p>Some people call what I'm describing "partial FL sizing" but it's much more than that. Partial is ian ndefinate word, it only means something less that maximum. What I'm talking about might better be called "custom FL sizing", doing it precisely to match YOUR chamber. </p><p> </p><p>Jamming a case into a FL die as far as it will go isn't very helpful for accuracy or case life. Fully restoring cases to original SAAMI dimensions only assures they will be made smaller than needed. The ONLY reason to do that would be so you could fire your reloads in every rirle ever made for that cartridge but that's NOT what you are going to do, is it?</p><p> </p><p>Custom FL sized cases will NOT stretch very much no matter how hot the load is so custom FL sized cases won't seperate at the head. Sure, the necks get worked a lot with FL does but ditto with neck dies. So, neck splits are what will kill most of your cases and, on average, it won't make a bit of difference if you neck size them or neck size them.</p><p> </p><p>Once your FL sizer is set, the ONLY reason to tweak it is to accomidate differences in hardness and springback; the brand, new, old, fired, unfired really isn't the issue. A gaging tool makes it pretty easy to adjust for a custom fit and you will soon learn how much change you need to make to see a difference. Die body threads are coarse at 14 turns per inch (about 72 thou per turn) so they require VERY SMALL changes during adjustment to avoid going too far. </p><p> </p><p>The full head space range for most bottleneck cartridges is around 6-7 thou. The oft seen suggestion to make <u>"small adjustments of 1/4 turn" actually moves the die about 18 thou, some three times the full min to max range</u>! Remember that 1 thou of change occurs with every 1/72th turn, so small changes mean exactly that, not the massive changes that usually get mentioned as "small"!</p><p> </p><p>Have fun!</p></blockquote><p></p>
[QUOTE="boomtube, post: 449316, member: 9215"] gunaddict62791 your questions are valid and some of the reasons for confusion are posted here. Fact is, Mr. Willis is fully correct about using a gage to get it right. But first you should know that "cam over" applies only to the press, not the dies or cartridge. All it means is that the lever and toggle has pushed the ram fully up and started back down a tad, "cammed over". It has no more meaning than for a press that comes to a full stop at top dead center and moves no further. Where the die is in that movement is the critical part and that is up to the user. Now, for very good accuracy, good case life and slick chambering, it's commonly considered to be better to FL size for sporting rifles each time. But, it IS best done with the minimum amount of working the case shoulder. A case shoulder gage (such as Mr. Willis sells - Goggle "Innovative Technologies", or the Hornady, Sinclair or RCBS tools) lets us actually measure where the shoulder of a fired case is. It CANNOT be done by eye or even feel, we must have a gage that measures to the thousant the distance from the case head to the shoulder. (Exactly where we measure to on a shoulder is irrelivant, the entire shoulder is equally usable for comparitive measuring! :) ) Somber instructions to adjust a sizer to touch the shell holder plus another magic 1/4 turn, etc, is silly. That presumes every press has the same amount of spring and slack in the lever linkages, every die has exactly the same inside diameter and internal length and every case will give exactly the same resistance to sizing. That's obviously not true. We must find what our combination actually requires, not follow some specific method that only gets most people in the right ball park. So, how much to "set shoulders back"? Well, why set then back at all? A fired case has expanded to the fit the chamber and sprung back a tad already, it will easily re-chamber just as it is. Therefore, why not simply set the FL sized shoulder back so the longest sized case is no longer than it was to start with? That will be fine, let the shorter ones fall where they will. I said adjust for the "longest" fired and resized case because individuals WILL vary some 2-3 thou both after firing [U]and[/U] after sizing; it's a fact of life that cases are NOT totally uniform in how they springback! Even seemingly trivial things as how hard you press on the lever, how long you hold the pressure, and how much of what type of case lube you use will make small sizing differences too! Some people call what I'm describing "partial FL sizing" but it's much more than that. Partial is ian ndefinate word, it only means something less that maximum. What I'm talking about might better be called "custom FL sizing", doing it precisely to match YOUR chamber. Jamming a case into a FL die as far as it will go isn't very helpful for accuracy or case life. Fully restoring cases to original SAAMI dimensions only assures they will be made smaller than needed. The ONLY reason to do that would be so you could fire your reloads in every rirle ever made for that cartridge but that's NOT what you are going to do, is it? Custom FL sized cases will NOT stretch very much no matter how hot the load is so custom FL sized cases won't seperate at the head. Sure, the necks get worked a lot with FL does but ditto with neck dies. So, neck splits are what will kill most of your cases and, on average, it won't make a bit of difference if you neck size them or neck size them. Once your FL sizer is set, the ONLY reason to tweak it is to accomidate differences in hardness and springback; the brand, new, old, fired, unfired really isn't the issue. A gaging tool makes it pretty easy to adjust for a custom fit and you will soon learn how much change you need to make to see a difference. Die body threads are coarse at 14 turns per inch (about 72 thou per turn) so they require VERY SMALL changes during adjustment to avoid going too far. The full head space range for most bottleneck cartridges is around 6-7 thou. The oft seen suggestion to make [U]"small adjustments of 1/4 turn" actually moves the die about 18 thou, some three times the full min to max range[/U]! Remember that 1 thou of change occurs with every 1/72th turn, so small changes mean exactly that, not the massive changes that usually get mentioned as "small"! Have fun! [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Newbie Needs Help Sizing!
Top