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Rifles, Reloading, Optics, Equipment
Reloading
.284 Win and RL 17
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<blockquote data-quote="Fitch" data-source="post: 376879" data-attributes="member: 19372"><p>Sure, with a disclaimer - I've not ever used RL17 - I'm planning to get a pound of it to try but I don't have any "real world" experience with it yet.</p><p> </p><p>Results would be more accurate if I knew the COL of the loads in question and the H2O capacity in grains of the fired, unsized, brass. Small changes in COL and brass capacity (which reflects chamber size) make significant changes in pressure because they affect the initial volume.</p><p> </p><p>The E-Tip bullet isn't in the QuickLOAD library and I don't have one to measure so I can add it, but if you can tell me the length of the bullet I can get pretty close by assuming it is the same shape as the 180g BT and adjusting the length.</p><p> </p><p>With the data you gave me for the .300WSM, assuming a max for the cartridge COAL and using the library value for brass capacity, and a 180 NBT in place of the E-Tip I get the following results:</p><p> </p><p>Input: 180g NBT, 2.860" COL, 81.3g H2O capacity, 67.5g RL17 (99.1% fill ratio), 24.375" barrel. </p><p> </p><p>Results: 3,188 fps, 79,601 psi. </p><p> </p><p>I don't really trust that answer because there are so many unknowns that can have a significant effect. To illustrate the sensitivity of the results to COL and H2O capacity, if the COL is 2.9", pressure drops 2,000 psi. If the water grain capacity is two grains more (fairely common) the pressure drops 5,000 psi. </p><p> </p><p>For the .25-06.</p><p> </p><p>Input: 115g Ballistic Silver Tip (which is in the QL library - I think it is a moly coated bullet so I adjusted the start pressure to 2400 psi), 3.25" COL, 26.0" barrel, 65.8g H2O capacity, 55.5g RL17 (95.5% fill).</p><p> </p><p>Results: 3,446 fps, 81,848 psi.</p><p> </p><p>These look high to me, but RL17 seems to have a reputation for modeling a little higher than it runs. QL isn't usually "that" far off though. The load that models at 90ksi in the original post is an over pressure load, I'm pretty sure of that. These may be just pretty stout if the right water grain capacity data is used. </p><p> </p><p>So, how does this compare with what you are seeing at the range and in the brass? And can you get H2O capacity data on your brass?</p><p> </p><p>If this is significantly different from what you expected and you have data for some other powders in these rifles I'd like to model that data as well to see if the issue is the QL model of RL17. </p><p> </p><p>Thanks</p><p>Fitch</p></blockquote><p></p>
[QUOTE="Fitch, post: 376879, member: 19372"] Sure, with a disclaimer - I've not ever used RL17 - I'm planning to get a pound of it to try but I don't have any "real world" experience with it yet. Results would be more accurate if I knew the COL of the loads in question and the H2O capacity in grains of the fired, unsized, brass. Small changes in COL and brass capacity (which reflects chamber size) make significant changes in pressure because they affect the initial volume. The E-Tip bullet isn't in the QuickLOAD library and I don't have one to measure so I can add it, but if you can tell me the length of the bullet I can get pretty close by assuming it is the same shape as the 180g BT and adjusting the length. With the data you gave me for the .300WSM, assuming a max for the cartridge COAL and using the library value for brass capacity, and a 180 NBT in place of the E-Tip I get the following results: Input: 180g NBT, 2.860" COL, 81.3g H2O capacity, 67.5g RL17 (99.1% fill ratio), 24.375" barrel. Results: 3,188 fps, 79,601 psi. I don't really trust that answer because there are so many unknowns that can have a significant effect. To illustrate the sensitivity of the results to COL and H2O capacity, if the COL is 2.9", pressure drops 2,000 psi. If the water grain capacity is two grains more (fairely common) the pressure drops 5,000 psi. For the .25-06. Input: 115g Ballistic Silver Tip (which is in the QL library - I think it is a moly coated bullet so I adjusted the start pressure to 2400 psi), 3.25" COL, 26.0" barrel, 65.8g H2O capacity, 55.5g RL17 (95.5% fill). Results: 3,446 fps, 81,848 psi. These look high to me, but RL17 seems to have a reputation for modeling a little higher than it runs. QL isn't usually "that" far off though. The load that models at 90ksi in the original post is an over pressure load, I'm pretty sure of that. These may be just pretty stout if the right water grain capacity data is used. So, how does this compare with what you are seeing at the range and in the brass? And can you get H2O capacity data on your brass? If this is significantly different from what you expected and you have data for some other powders in these rifles I'd like to model that data as well to see if the issue is the QL model of RL17. Thanks Fitch [/QUOTE]
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.284 Win and RL 17
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