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
264 win mag
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="CONatureBoy" data-source="post: 2201177" data-attributes="member: 118769"><p>I agree, of course, that QuickLoad generates maps, not territories. But they're very useful maps, especially for comparing bullets, powders, and calibers. In my experience QuickLoad is usually within 25 fps of actual muzzle velocities, as long as I'm careful to input all of the relevant parameters, especially cartridge and barrel length. (As far as I know, QuickLoad doesn't let the user input some parameters relevant to internal ballistics, notably ambient or cartridge temperature.) My point about the hot loads is that readers need to realize that claims of muzzle velocities well in excess of published velocities, or velocities estimated by QuickLoad, should be understood as statistical outliers, upper limits that one might or might not be able to duplicate safely if they approach handloading with appropriate caution.</p><p></p><p>To make a fair comparison between calibers, one should not compare hot-load velocities reported by a single hand loader (who may shoot a 28-30" barrel) with velocities obtained under laboratory conditions within SAAMI pressure guidelines, and using standard (22-26") barrel lengths, by professional ballisticians at Nosler, Hornady, etc., and published in reloading manuals. That's comparing apples to oranges. To answer the question "Which caliber shoots faster?", a more scientific approach is to pick a bullet and a barrel length, and then for each caliber you want to compare, use QuickLoad to estimate a maximum load with whatever powder achieves maximal muzzle velocity for the caliber, using the default (SAAMI) COAL and Pmax (SAAMI-specified maximum safe pressure) for each caliber. (H1000 might be faster in a 6.5-284, but RE-26 might be faster in a 264 Win Mag, for a given bullet.) Then you compare those muzzle velocities.</p><p></p><p>I realize that SAAMI specifies different Pmax values for different calibers. Some (especially older) rifle calibers may have Pmax values in the 50,000 psi range, while modern calibers are usually in the 60,000-65,000 psi range. If you read the SAAMI specifications, you'll</p><p></p><p>I recommend that novice hand loaders read carefully the "Velocity & Pressure" section (pages 5-35) of the current SAAMI Standards document at <a href="https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.4-CFR-Approved-2015-12-14-Posting-Copy.pdf" target="_blank">https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.4-CFR-Approved-2015-12-14-Posting-Copy.pdf</a>.</p><p></p><p>I agree, of course, that QuickLoad generates maps, not territories. But they're very useful maps, in two senses: (1) they make for a scientifically well-founded, apples-to-apples comparison between calibers, and (2) in my experience developing dozens of handloads they're usually within 25 fps of actual performance, as long as I'm careful to enter the true COAL and barrel length, and to develop loads at roughly the same ambient temperature.</p><p></p><p>It is not scientifically sound to compare a single hand loader's hot loads either to max loads published in reloading manuals, or to max loads estimated by QuickLoad. A single hand loader's results for a single rifle (and bullet) are just one "data point," one member of a large statistical population of rifles. If that one rifle happens to produce exceptional muzzle velocities, we need to be careful to treat them that way: they're outliers, upper limits to what one might hope for. They're not scientifically well-founded estimates of what one may reasonably expect from any rifle randomly chosen from that population. Sure, carefully built rifles and pricey semi-custom rifles are a non-random sub-population of that larger population. They may have more favorable average numbers than the larger population. But (as a purely mathematical matter) a single sample from that sub-population does not provide anything close to scientifically adequate evidence for such a claim. Suggesting otherwise, and encouraging others to seek exceptional muzzle velocities by developing hot loads based on one shooter's experience, encourages others to wander into the Land of Unsafe Peak Pressures. Sometimes the first "sign of unsafe pressure" is the barrel or action failing explosively. That's a big risk to take, hoping to gain a few fps that for almost any shooter will never matter in the field (or even, for most shooters, in competition). </p><p></p><p>I encourage novice hand loaders to read carefully the "Velocity & Pressure" section (pages 5-25) of SAAMI's current standards, available for download at <a href="https://saami.org/technical-information/ansi-saami-standards/" target="_blank">https://saami.org/technical-information/ansi-saami-standards/</a>. Quoting from that section:</p><p></p><p><em>Due to the fact that sporting firearms for general distribution are typically manufactured to dimensional tolerances greater than those specified for test barrels, there should be no expectation that these velocities can be duplicated from any test utilizing firearms. This situation is further confounded by discrepancies in barrel length. Furthermore, once ammunition has left the control of the manufacturer, storage conditions outside those recommended by the manufacturer may cause variations in the velocity as measured using test equipment and procedures which conform to the requirements of this Standard.</em></p><p></p><p>Thus SAAMI reports a mean velocity of 3,105 fps for a 140-grain bullet in its tests at a maximum average transducer pressure of 64,000 psi (or crusher pressure of 54,000 cup). </p><p></p><p>One scientifically sound way to compare caliber performance is to look at these SAAMI numbers. Another way is to compare the maximum achievable velocities reported for a given bullet across calibers in a reloading manual. The professional ballisticians produce those numbers under very controlled conditions, repeating experiments enough times to obtain statistically defensible scientific conclusions about achievable muzzle velocities. Given a bullet, the numbers in the manuals can suggest which powders produce the fastest loads for a given caliber. That scientific, and it's also prudent, safe.</p><p></p><p>I use QuickLoad in a similar fashion. I compare calibers using the same bullet and barrel length, and using each caliber's SAAMI-specified COAL (the default value in QuickLoad), but choosing whatever powder maximizes muzzle velocity (at maximum safe pressure) for that caliber. That tells me, in some sense, which caliber is "faster." It's a fun exercise, and it can suggest which powders are likely to produce the fastest loads for a given bullet and caliber.</p><p></p><p>I strongly advise anyone reading this post to pay close attention to the advice in the reloading manuals about "approaching maximum loads with caution." I personally follow the "ladder procedure" (see <a href="https://precisionrifleblog.com/2012/07/13/creighton-audette-ladder-testing/" target="_blank">https://precisionrifleblog.com/2012/07/13/creighton-audette-ladder-testing/</a> for details), and I work up in 0.5- to 0.2-grain increments, depending on various things. Not only does the ladder procedure help you find accuracy nodes, it helps you approach maximum safe loads with an appropriate degree of caution. </p><p></p><p>Finally, I advise novice hand loaders to find the most accurate load possible in an acceptable velocity range. I myself have done this with my own rifles in a way that results in all three of my long-range rifles having the same drop curve out to 600 yards. I don't have to try to remember three drop curves for three rifles. That makes it easier to hit near my point of aim in the field. Hot loads burn out barrels. "Speed thrills, but accuracy kills."</p></blockquote><p></p>
[QUOTE="CONatureBoy, post: 2201177, member: 118769"] I agree, of course, that QuickLoad generates maps, not territories. But they're very useful maps, especially for comparing bullets, powders, and calibers. In my experience QuickLoad is usually within 25 fps of actual muzzle velocities, as long as I'm careful to input all of the relevant parameters, especially cartridge and barrel length. (As far as I know, QuickLoad doesn't let the user input some parameters relevant to internal ballistics, notably ambient or cartridge temperature.) My point about the hot loads is that readers need to realize that claims of muzzle velocities well in excess of published velocities, or velocities estimated by QuickLoad, should be understood as statistical outliers, upper limits that one might or might not be able to duplicate safely if they approach handloading with appropriate caution. To make a fair comparison between calibers, one should not compare hot-load velocities reported by a single hand loader (who may shoot a 28-30" barrel) with velocities obtained under laboratory conditions within SAAMI pressure guidelines, and using standard (22-26") barrel lengths, by professional ballisticians at Nosler, Hornady, etc., and published in reloading manuals. That's comparing apples to oranges. To answer the question "Which caliber shoots faster?", a more scientific approach is to pick a bullet and a barrel length, and then for each caliber you want to compare, use QuickLoad to estimate a maximum load with whatever powder achieves maximal muzzle velocity for the caliber, using the default (SAAMI) COAL and Pmax (SAAMI-specified maximum safe pressure) for each caliber. (H1000 might be faster in a 6.5-284, but RE-26 might be faster in a 264 Win Mag, for a given bullet.) Then you compare those muzzle velocities. I realize that SAAMI specifies different Pmax values for different calibers. Some (especially older) rifle calibers may have Pmax values in the 50,000 psi range, while modern calibers are usually in the 60,000-65,000 psi range. If you read the SAAMI specifications, you'll I recommend that novice hand loaders read carefully the "Velocity & Pressure" section (pages 5-35) of the current SAAMI Standards document at [URL]https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.4-CFR-Approved-2015-12-14-Posting-Copy.pdf[/URL]. I agree, of course, that QuickLoad generates maps, not territories. But they're very useful maps, in two senses: (1) they make for a scientifically well-founded, apples-to-apples comparison between calibers, and (2) in my experience developing dozens of handloads they're usually within 25 fps of actual performance, as long as I'm careful to enter the true COAL and barrel length, and to develop loads at roughly the same ambient temperature. It is not scientifically sound to compare a single hand loader's hot loads either to max loads published in reloading manuals, or to max loads estimated by QuickLoad. A single hand loader's results for a single rifle (and bullet) are just one "data point," one member of a large statistical population of rifles. If that one rifle happens to produce exceptional muzzle velocities, we need to be careful to treat them that way: they're outliers, upper limits to what one might hope for. They're not scientifically well-founded estimates of what one may reasonably expect from any rifle randomly chosen from that population. Sure, carefully built rifles and pricey semi-custom rifles are a non-random sub-population of that larger population. They may have more favorable average numbers than the larger population. But (as a purely mathematical matter) a single sample from that sub-population does not provide anything close to scientifically adequate evidence for such a claim. Suggesting otherwise, and encouraging others to seek exceptional muzzle velocities by developing hot loads based on one shooter's experience, encourages others to wander into the Land of Unsafe Peak Pressures. Sometimes the first "sign of unsafe pressure" is the barrel or action failing explosively. That's a big risk to take, hoping to gain a few fps that for almost any shooter will never matter in the field (or even, for most shooters, in competition). I encourage novice hand loaders to read carefully the "Velocity & Pressure" section (pages 5-25) of SAAMI's current standards, available for download at [URL]https://saami.org/technical-information/ansi-saami-standards/[/URL]. Quoting from that section: [I]Due to the fact that sporting firearms for general distribution are typically manufactured to dimensional tolerances greater than those specified for test barrels, there should be no expectation that these velocities can be duplicated from any test utilizing firearms. This situation is further confounded by discrepancies in barrel length. Furthermore, once ammunition has left the control of the manufacturer, storage conditions outside those recommended by the manufacturer may cause variations in the velocity as measured using test equipment and procedures which conform to the requirements of this Standard.[/I] Thus SAAMI reports a mean velocity of 3,105 fps for a 140-grain bullet in its tests at a maximum average transducer pressure of 64,000 psi (or crusher pressure of 54,000 cup). One scientifically sound way to compare caliber performance is to look at these SAAMI numbers. Another way is to compare the maximum achievable velocities reported for a given bullet across calibers in a reloading manual. The professional ballisticians produce those numbers under very controlled conditions, repeating experiments enough times to obtain statistically defensible scientific conclusions about achievable muzzle velocities. Given a bullet, the numbers in the manuals can suggest which powders produce the fastest loads for a given caliber. That scientific, and it's also prudent, safe. I use QuickLoad in a similar fashion. I compare calibers using the same bullet and barrel length, and using each caliber's SAAMI-specified COAL (the default value in QuickLoad), but choosing whatever powder maximizes muzzle velocity (at maximum safe pressure) for that caliber. That tells me, in some sense, which caliber is "faster." It's a fun exercise, and it can suggest which powders are likely to produce the fastest loads for a given bullet and caliber. I strongly advise anyone reading this post to pay close attention to the advice in the reloading manuals about "approaching maximum loads with caution." I personally follow the "ladder procedure" (see [URL]https://precisionrifleblog.com/2012/07/13/creighton-audette-ladder-testing/[/URL] for details), and I work up in 0.5- to 0.2-grain increments, depending on various things. Not only does the ladder procedure help you find accuracy nodes, it helps you approach maximum safe loads with an appropriate degree of caution. Finally, I advise novice hand loaders to find the most accurate load possible in an acceptable velocity range. I myself have done this with my own rifles in a way that results in all three of my long-range rifles having the same drop curve out to 600 yards. I don't have to try to remember three drop curves for three rifles. That makes it easier to hit near my point of aim in the field. Hot loads burn out barrels. "Speed thrills, but accuracy kills." [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Rifles, Bullets, Barrels & Ballistics
264 win mag
Top