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
Rifles, Bullets, Barrels & Ballistics
6mm Hammer bullets
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="RockyMtnMT" data-source="post: 1775773" data-attributes="member: 7999"><p>[USER=9467]@adam32[/USER]</p><p></p><p>The problem is this bullet is close to 6x caliber in length. 6x caliber in length seems to be the threshold where bullets have terrible dynamic stability issues. </p><p></p><p>I always do my calculations at sea level and don't consider elevation for hunting. What we see with the Miller stability formula is it was created at a time when there was no such thing as non lead bullets and there just wasn't long for caliber bullets. Thus the formula does not take into account material density. What we see is the longer for caliber bullets get the required twist needed goes up more rapidly. I would say that long for caliber bullets that are pure copper are fully stable at 2.0 sg at sea level.</p><p></p><p>It is interesting that our very long for caliber bullets shoot very well for some guys with the min twist and others shoot them sideways with the same twist. For a while I was going to remove several of the bullets from the site. Every time I was ready to delete a bullet I would get a report from a customer that is shooting it lights out. High air density plays heck on them. Also very high vel can cause issues. Makes them want to swap ends. We designed a 165g 6.5mm bullet for a 6" twist rifle that we have been working on for [USER=30671]@HARPERC[/USER]. It was shooting great until we broke 3300fps, then it started printing oblong holes at 200y. We have a customer that is running our 73g .224 cal bullet very well. Once he broke 3700 fps they started shooting sideways. The 83g .224 has these issues as well but worse. But then there is a bunch of guys that shoot it great.</p><p></p><p>I will be very interested in you results.</p></blockquote><p></p>
[QUOTE="RockyMtnMT, post: 1775773, member: 7999"] [USER=9467]@adam32[/USER] The problem is this bullet is close to 6x caliber in length. 6x caliber in length seems to be the threshold where bullets have terrible dynamic stability issues. I always do my calculations at sea level and don't consider elevation for hunting. What we see with the Miller stability formula is it was created at a time when there was no such thing as non lead bullets and there just wasn't long for caliber bullets. Thus the formula does not take into account material density. What we see is the longer for caliber bullets get the required twist needed goes up more rapidly. I would say that long for caliber bullets that are pure copper are fully stable at 2.0 sg at sea level. It is interesting that our very long for caliber bullets shoot very well for some guys with the min twist and others shoot them sideways with the same twist. For a while I was going to remove several of the bullets from the site. Every time I was ready to delete a bullet I would get a report from a customer that is shooting it lights out. High air density plays heck on them. Also very high vel can cause issues. Makes them want to swap ends. We designed a 165g 6.5mm bullet for a 6" twist rifle that we have been working on for [USER=30671]@HARPERC[/USER]. It was shooting great until we broke 3300fps, then it started printing oblong holes at 200y. We have a customer that is running our 73g .224 cal bullet very well. Once he broke 3700 fps they started shooting sideways. The 83g .224 has these issues as well but worse. But then there is a bunch of guys that shoot it great. I will be very interested in you results. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
6mm Hammer bullets
Top