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
224 Valkyrie Bullet Choices for 6.5 Twist Barrel
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="RegionRat" data-source="post: 2811058" data-attributes="member: 57231"><p>You mentioned 1:7 twist, is that right?</p><p>For that long 64 Hammer bullet, here is what they recommend.</p><p></p><p>[ATTACH=full]460087[/ATTACH]</p><p></p><p></p><p>Ambient pressure (altitude) plays a role in stability. The higher you are, the easier it gets because the average pressure is lower and that makes for less dense air flow to destabilize the bullet. You are doing better than their recommended 1:8.5 so you should be fine.</p><p></p><p>If you have the bullet dimensions, it isn't difficult to run the SG numbers. Just keep in mind those are not real hard stability calculations so take them with a grain of salt.... You would like to run a SG of 1.5 or just a little higher, but if you drop under 1.5 it isn't instant death.</p><p></p><p>If you were running below SG 1.5, you have less margin and some of the shots may act like they have a worse BC value, some may not. Take that number closer to SG 1.0 and you will almost certainly see poor performance or even tumbling. Those ones in the grey zone of say SG1.25 - 1.35 often give a poor vertical performance at distance because some will wobble and some will not. </p><p></p><p>Here is their 1:8.5 at sea level and MV 2650,</p><p>[ATTACH=full]460088[/ATTACH]</p><p></p><p>And here is your 1:7</p><p>[ATTACH=full]460089[/ATTACH]</p></blockquote><p></p>
[QUOTE="RegionRat, post: 2811058, member: 57231"] You mentioned 1:7 twist, is that right? For that long 64 Hammer bullet, here is what they recommend. [ATTACH type="full"]460087[/ATTACH] Ambient pressure (altitude) plays a role in stability. The higher you are, the easier it gets because the average pressure is lower and that makes for less dense air flow to destabilize the bullet. You are doing better than their recommended 1:8.5 so you should be fine. If you have the bullet dimensions, it isn't difficult to run the SG numbers. Just keep in mind those are not real hard stability calculations so take them with a grain of salt.... You would like to run a SG of 1.5 or just a little higher, but if you drop under 1.5 it isn't instant death. If you were running below SG 1.5, you have less margin and some of the shots may act like they have a worse BC value, some may not. Take that number closer to SG 1.0 and you will almost certainly see poor performance or even tumbling. Those ones in the grey zone of say SG1.25 - 1.35 often give a poor vertical performance at distance because some will wobble and some will not. Here is their 1:8.5 at sea level and MV 2650, [ATTACH type="full"]460088[/ATTACH] And here is your 1:7 [ATTACH type="full"]460089[/ATTACH] [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
224 Valkyrie Bullet Choices for 6.5 Twist Barrel
Top