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
Reloder 26, Temperature Stability Sensitivity Data
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="Pdvdh" data-source="post: 1394785" data-attributes="member: 4191"><p>I agree the temperature affect on velocity isn't linear. Just hoping that the temps most are testing across and reporting for are typical fall hunting temperatures.</p><p>I've tested different temperature rate values with two different cartridges across the same temperature ranges. Here's an example with RL33.</p><p></p><p><u>338 Lapua Improved, <strong>RL33</strong>, 300gr Berger OTM</u>:</p><p>Temp Sensitivity between 23 and 68*F = <strong>0.48</strong>fps/*F</p><p>Temp Sensitivity between -4 and 23*F = <strong>1.44</strong>fps/*F</p><p>I hunt between 23F and 68F, so it's very workable in that range in my 338 Lapua Improved. Sensitivity picks up once the temp drops below 23F, but doesn't matter to me. I'm not hunting in those cooler temps.</p><p></p><p><u>30/375 S.I., <strong>RL33</strong>, 215gr Berger Hybrid</u>:</p><p>Temp Sensitivity between 23 and 68*F = <strong>0.67</strong>fps/*F</p><p>Temp Sensitivity between -4 and 23*F = <strong>1.44</strong>fps/*F</p><p>The 1.44fps/*F duplication isn't a typo or error. Just happened to record the same 39fps difference in MV with both cartridges across those temperature ranges. This colder temp data also included MV recorded at 5*F.</p><p></p><p>Different bullet weights might also change the temp rate change on MV with the same cartridge. I haven't tested for that. I only test the bullet I hunt with.</p><p></p><p><u>Anyhow, back to <strong>RL26</strong></u>... if members can add the temperature ranges they tested across, that would be a fringe benefit! Two members posting around 0.5fps/*F which is consistent with Alliant's testing. So I'm already off to a good starting value. I'll do my own testing along the way, but it takes time, and I'm just getting started with RL26.</p><p></p><p>When I test, I bring the ammo and the rifles completely down to outdoor ambient temps. I fire at a slow rate, allowing the barrel to come back down to ambient temp. It's tedious, and it's time consuming. I don't expect most will be doing this. That's fine. Not holding anyone to the nitty gritty details. Whatever you have established will help get us in the ballpark.</p><p></p><p>Eventually I'll update with my own test results. But, don't hold your breath waiting. I do this over months. Not weeks. I continue to refine it with the bullet I hunt with until I end up with pretty solid numbers for my loads in my rifles. I never collect data in temps above ~72*F. Because it's a cold day in you know what before we ever see a temp above 72*F where I live in Alaska... <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /></p></blockquote><p></p>
[QUOTE="Pdvdh, post: 1394785, member: 4191"] I agree the temperature affect on velocity isn't linear. Just hoping that the temps most are testing across and reporting for are typical fall hunting temperatures. I've tested different temperature rate values with two different cartridges across the same temperature ranges. Here's an example with RL33. [U]338 Lapua Improved, [B]RL33[/B], 300gr Berger OTM[/U]: Temp Sensitivity between 23 and 68*F = [B]0.48[/B]fps/*F Temp Sensitivity between -4 and 23*F = [B]1.44[/B]fps/*F I hunt between 23F and 68F, so it's very workable in that range in my 338 Lapua Improved. Sensitivity picks up once the temp drops below 23F, but doesn't matter to me. I'm not hunting in those cooler temps. [U]30/375 S.I., [B]RL33[/B], 215gr Berger Hybrid[/U]: Temp Sensitivity between 23 and 68*F = [B]0.67[/B]fps/*F Temp Sensitivity between -4 and 23*F = [B]1.44[/B]fps/*F The 1.44fps/*F duplication isn't a typo or error. Just happened to record the same 39fps difference in MV with both cartridges across those temperature ranges. This colder temp data also included MV recorded at 5*F. Different bullet weights might also change the temp rate change on MV with the same cartridge. I haven't tested for that. I only test the bullet I hunt with. [U]Anyhow, back to [B]RL26[/B][/U]... if members can add the temperature ranges they tested across, that would be a fringe benefit! Two members posting around 0.5fps/*F which is consistent with Alliant's testing. So I'm already off to a good starting value. I'll do my own testing along the way, but it takes time, and I'm just getting started with RL26. When I test, I bring the ammo and the rifles completely down to outdoor ambient temps. I fire at a slow rate, allowing the barrel to come back down to ambient temp. It's tedious, and it's time consuming. I don't expect most will be doing this. That's fine. Not holding anyone to the nitty gritty details. Whatever you have established will help get us in the ballpark. Eventually I'll update with my own test results. But, don't hold your breath waiting. I do this over months. Not weeks. I continue to refine it with the bullet I hunt with until I end up with pretty solid numbers for my loads in my rifles. I never collect data in temps above ~72*F. Because it's a cold day in you know what before we ever see a temp above 72*F where I live in Alaska... :) [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Reloder 26, Temperature Stability Sensitivity Data
Top