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
To bush or mandrel
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="Mikecr" data-source="post: 2131050" data-attributes="member: 1521"><p>Sizing means yielding.</p><p>That is, dimension change beyond springback causes yielding, and yielded only allows partial recovery to a new dimension (i.e. sizing). </p><p>When downsizing necks for more than ~1thou interference, seated bullet bearing will just re-expand/size that much of it. </p><p></p><p>Unless you size necks beyond seated bearing, you have no more than springback energy from cal dimension gripping your bullet (tension).</p><p>This is not a 'problem' as that's what you have.</p><p>Where you do size necks beyond seated bearing, you add bearing-base binding and bring donut area/shoulder angle into tension, which is a horrible plan for hunting capacity cartridges.</p><p></p><p>Good minimal sizing brings necks down ~2thou interference (after springback) for no more length than seated bullet bearing. This would be followed by an expander mandrel at cal in a pre-seating operation. That drives any thickness variance into yielding outward, away from seating bullets, to reduce loaded runout. It also sets interference to ~1thou, which is what you'll have anyway, but without using your bullets for expansion sizing. Better to use a mandrel for this, as bullets make terrible mandrels.</p><p>If you had left a carbon layer in necks (the perfect lube) then with this sizing plan you reduce seating forces, so you reduce seating depth variance. It get's a lot easier to set exact CBTO.</p><p>Less annealing rate is needed. And tension is then tweaked through sizing LENGTH adjustment (with a bushing die).</p><p>After all, neck tension is springback force X area applied to seated bearing. It's PSI.</p><p></p><p>Whatever you do, apply it through load development.</p></blockquote><p></p>
[QUOTE="Mikecr, post: 2131050, member: 1521"] Sizing means yielding. That is, dimension change beyond springback causes yielding, and yielded only allows partial recovery to a new dimension (i.e. sizing). When downsizing necks for more than ~1thou interference, seated bullet bearing will just re-expand/size that much of it. Unless you size necks beyond seated bearing, you have no more than springback energy from cal dimension gripping your bullet (tension). This is not a 'problem' as that's what you have. Where you do size necks beyond seated bearing, you add bearing-base binding and bring donut area/shoulder angle into tension, which is a horrible plan for hunting capacity cartridges. Good minimal sizing brings necks down ~2thou interference (after springback) for no more length than seated bullet bearing. This would be followed by an expander mandrel at cal in a pre-seating operation. That drives any thickness variance into yielding outward, away from seating bullets, to reduce loaded runout. It also sets interference to ~1thou, which is what you'll have anyway, but without using your bullets for expansion sizing. Better to use a mandrel for this, as bullets make terrible mandrels. If you had left a carbon layer in necks (the perfect lube) then with this sizing plan you reduce seating forces, so you reduce seating depth variance. It get's a lot easier to set exact CBTO. Less annealing rate is needed. And tension is then tweaked through sizing LENGTH adjustment (with a bushing die). After all, neck tension is springback force X area applied to seated bearing. It's PSI. Whatever you do, apply it through load development. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
To bush or mandrel
Top