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Rifles, Reloading, Optics, Equipment
Reloading
300 RUM powder choice
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<blockquote data-quote="goodgrouper" data-source="post: 134674" data-attributes="member: 2852"><p>Very interesting. I know you guys aren't bs'ing me and I hope you know I'm not bs'ing you either. Perhaps I have an ultra slow lot of Retumbo or something, but here is my numbers from the last 300 ultra I worked on. <strong>Warning: These loads were started from bottom and were worked up to in incrementations in controlled circumstances in a rifle that had Final Finish fired in it for breakin purposes and will be too HOT for guns that have not had FF fired through them. </strong> It is good for at least two grains of extra powder because of the reduction in friction in factory barrels. I list them for comparison only. Do not load these loads unless you have fired FF through the barrel and even then, proceed with caution!</p><p></p><p>All loads fired through Oehler 35 on 4' rod in 80 degree weather.</p><p>All are 200 grain Nosler Accubonds seated to 2.983" ogive to base measurement so as to fit just barely into an unaltered Remington magazine.</p><p></p><p>Retumbo</p><p>row 1 97.5 grains</p><p>es 18 av 3144</p><p>row 2 98.0 grains</p><p>es 35 av 3199</p><p>row 3 98.5 grains</p><p>es 7 av 3213</p><p>row 4 99.0 grains</p><p>es 16 av 3217</p><p>row 5 99.5 grains</p><p>es 33 av 3244</p><p></p><p>All rows crunched kernels seating the bullets. Last two rows unseated bullets .015".</p><p>conclusion: subtract 2 grains from the optimum charge of 98.5 for normal barrels and you would have 96.5 grains which is still crunching kernels fairly bad and it would probably generate a speed in the area of 3150 fps. Optimum burn rate of Retumbo for 95%-100% load density would put it too slow for this particular cartridge combo. Standard deviations in the single digits for a high end sweet spot are going to be in a charge that is too much for the case volume.</p><p></p><p></p><p></p><p></p><p></p><p>H1000</p><p></p><p>94.5 grains</p><p>es 9</p><p>av 3088</p><p></p><p>95.0 grains</p><p>es 23</p><p>av 3093</p><p></p><p>95.5 grains</p><p>es 7 </p><p>av 3094</p><p></p><p>96.0 grains</p><p>es 31</p><p>av 3130</p><p></p><p>96.5 grains</p><p>es 5</p><p>av 3160</p><p></p><p>conclusion: 97 grains not tried because significant kernels were being crunched and the high end sweet spot was attained. H1000 topped out at 96.5 but was short of 3200 fps. H1000 is slightly too slow for this particular rifle and it is faster in burn rate than Retumbo.</p><p></p><p></p><p></p><p></p><p>Rl25</p><p>95 grains</p><p>es 5</p><p>av 3169</p><p></p><p>95.5 grains</p><p>es 8</p><p>av 3185</p><p></p><p>96.0 grains</p><p>es 16</p><p>av 3210</p><p></p><p>96.5 grains</p><p>es 16</p><p>av 3230</p><p></p><p>Conclusion: top end sweet spot attained at 96 grains (94 in normal barrel) and few kernels were crunched. Near perfect load density at 100% or so. Good speed as well. High end sweet spot is good charge for load density attained.</p><p></p><p></p><p></p><p></p><p></p><p>IMR7828ssc</p><p>93.0 grains</p><p>es 20</p><p>av 3233</p><p></p><p>93.5 grains</p><p>es 7 </p><p>av 3255</p><p></p><p></p><p>94.0 grains</p><p>es 10</p><p>av 3278</p><p></p><p>94.5 grains</p><p>es 14</p><p>av 3291</p><p></p><p>95.0 grains not tried because significant pressure was showing. </p><p>COnclusion: IMR7828 offered really good velo uniformity across all charges and high end sweet spots were hard to distinguish. Best groups were attained with 94 grains (92 in normal barrel) for a speed of 3278 and a load density of roughly 90-95%. It seemed to hit it's preferred pressure harmonic at 90% load density, shot extremely uniform, was accurate, and was produced more velo than all other powders tried. Burn rate is nearly as ideal as RL25.</p><p></p><p></p><p></p><p>Now this is just my last experiment and it shows comparitive burn rates in this case and in this caliber. You might have a gun that shoots great crammed clear full of Retumbo, but it is not in an ideal burn rate for a 300 ultra with bullets as light as 200 grains. My 6br shoots lights out with a case crammed clear full of H4831sc, but velo suffers tremendously. A more appropriate powder for that small case and the 105 bullets is Varget which is comparitively much "quicker" on the burn rate chart.</p><p></p><p>Clear as mud right?</p></blockquote><p></p>
[QUOTE="goodgrouper, post: 134674, member: 2852"] Very interesting. I know you guys aren't bs'ing me and I hope you know I'm not bs'ing you either. Perhaps I have an ultra slow lot of Retumbo or something, but here is my numbers from the last 300 ultra I worked on. [b]Warning: These loads were started from bottom and were worked up to in incrementations in controlled circumstances in a rifle that had Final Finish fired in it for breakin purposes and will be too HOT for guns that have not had FF fired through them. [/b] It is good for at least two grains of extra powder because of the reduction in friction in factory barrels. I list them for comparison only. Do not load these loads unless you have fired FF through the barrel and even then, proceed with caution! All loads fired through Oehler 35 on 4' rod in 80 degree weather. All are 200 grain Nosler Accubonds seated to 2.983" ogive to base measurement so as to fit just barely into an unaltered Remington magazine. Retumbo row 1 97.5 grains es 18 av 3144 row 2 98.0 grains es 35 av 3199 row 3 98.5 grains es 7 av 3213 row 4 99.0 grains es 16 av 3217 row 5 99.5 grains es 33 av 3244 All rows crunched kernels seating the bullets. Last two rows unseated bullets .015". conclusion: subtract 2 grains from the optimum charge of 98.5 for normal barrels and you would have 96.5 grains which is still crunching kernels fairly bad and it would probably generate a speed in the area of 3150 fps. Optimum burn rate of Retumbo for 95%-100% load density would put it too slow for this particular cartridge combo. Standard deviations in the single digits for a high end sweet spot are going to be in a charge that is too much for the case volume. H1000 94.5 grains es 9 av 3088 95.0 grains es 23 av 3093 95.5 grains es 7 av 3094 96.0 grains es 31 av 3130 96.5 grains es 5 av 3160 conclusion: 97 grains not tried because significant kernels were being crunched and the high end sweet spot was attained. H1000 topped out at 96.5 but was short of 3200 fps. H1000 is slightly too slow for this particular rifle and it is faster in burn rate than Retumbo. Rl25 95 grains es 5 av 3169 95.5 grains es 8 av 3185 96.0 grains es 16 av 3210 96.5 grains es 16 av 3230 Conclusion: top end sweet spot attained at 96 grains (94 in normal barrel) and few kernels were crunched. Near perfect load density at 100% or so. Good speed as well. High end sweet spot is good charge for load density attained. IMR7828ssc 93.0 grains es 20 av 3233 93.5 grains es 7 av 3255 94.0 grains es 10 av 3278 94.5 grains es 14 av 3291 95.0 grains not tried because significant pressure was showing. COnclusion: IMR7828 offered really good velo uniformity across all charges and high end sweet spots were hard to distinguish. Best groups were attained with 94 grains (92 in normal barrel) for a speed of 3278 and a load density of roughly 90-95%. It seemed to hit it's preferred pressure harmonic at 90% load density, shot extremely uniform, was accurate, and was produced more velo than all other powders tried. Burn rate is nearly as ideal as RL25. Now this is just my last experiment and it shows comparitive burn rates in this case and in this caliber. You might have a gun that shoots great crammed clear full of Retumbo, but it is not in an ideal burn rate for a 300 ultra with bullets as light as 200 grains. My 6br shoots lights out with a case crammed clear full of H4831sc, but velo suffers tremendously. A more appropriate powder for that small case and the 105 bullets is Varget which is comparitively much "quicker" on the burn rate chart. Clear as mud right? [/QUOTE]
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300 RUM powder choice
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