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
Sort by bearing length and by weight?
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="Bart B" data-source="post: 608725" data-attributes="member: 5302"><p>I'd say it's external. Whatever it is, it will determine to some extent the meplat shape of a hollow point.</p><p></p><p>The other internal thing is balance. With perfect dimensions in jackets and cores before they're seated and the ogive formed, the core may not be perfectly uniform around the inside of the jacket. Maybe the lead's not perfectly homogenous; one side's heavier than the other.</p><p></p><p>A friend spun some 30 caliber match bullets that had been run through an optical comparator to ensure uniform outside dimensions. Spun at 30,000 rpm, the worst unbalanced ones flew out of the collet holding them. Best ones drew the least amount of current to the motor spinning the collet; evidence there was no unbalance to load the motor bearings up and require more current to spin it up to speed.</p><p></p><p>Those perfect bullets shot an inch or less at 600 yards; the others worse depending on how much unbalanced they were.</p><p></p><p>Bullet companies shooting bullets through chronographs and timers have observed that bullets leaving at the same speed have different BC's. That's caused by the slight unbalance bullets have; the more there is the more drag the bullet has so it's BC will be lower.</p><p></p><p>All of which, to me, means that measuring all the static properties of bullets then sorting them into "perfect" and lesser lots, those "perfect" ones will still have some degree of unbalance that'll cause small accuracy issues. So it's gonna be hard to differentiate between what causes inaccuracy, slight unbalance or mechanically measured differences.</p></blockquote><p></p>
[QUOTE="Bart B, post: 608725, member: 5302"] I'd say it's external. Whatever it is, it will determine to some extent the meplat shape of a hollow point. The other internal thing is balance. With perfect dimensions in jackets and cores before they're seated and the ogive formed, the core may not be perfectly uniform around the inside of the jacket. Maybe the lead's not perfectly homogenous; one side's heavier than the other. A friend spun some 30 caliber match bullets that had been run through an optical comparator to ensure uniform outside dimensions. Spun at 30,000 rpm, the worst unbalanced ones flew out of the collet holding them. Best ones drew the least amount of current to the motor spinning the collet; evidence there was no unbalance to load the motor bearings up and require more current to spin it up to speed. Those perfect bullets shot an inch or less at 600 yards; the others worse depending on how much unbalanced they were. Bullet companies shooting bullets through chronographs and timers have observed that bullets leaving at the same speed have different BC's. That's caused by the slight unbalance bullets have; the more there is the more drag the bullet has so it's BC will be lower. All of which, to me, means that measuring all the static properties of bullets then sorting them into "perfect" and lesser lots, those "perfect" ones will still have some degree of unbalance that'll cause small accuracy issues. So it's gonna be hard to differentiate between what causes inaccuracy, slight unbalance or mechanically measured differences. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Sort by bearing length and by weight?
Top