BillC79
Gold $$ Contributor
As part of a study on temperature sensitivities of powders for .223 Wylde high power service rifles, I had a chance to compare old and new Vihtavuori N140 under the same conditions. Since I was unable to find data on the new N140, I am posting mine here for more easy access in online searches. Apologies to the forum editor if double posting of the same data on the forum is prohibited.
The link to the full study in progress is below and is being discussed in a separate thread on this forum:
The newer N140 is reported (and advertised) to be “Temperature-stable” and to contain a “Decoppering agent.”
The new N140 appears to be less temperature sensitive below 68°F (20°C) than the old in the temperature range I tested. New N140 produces significantly higher velocity than the old at the same case charge with a 77 grain bullet. Both the new and the old N140 are moderately temperature sensitive above 68°F compared to Varget. With a case powder charge of 24.3 grains, both the old and the new N140 at 129°F (54°C) produce overpressure signs on primers (primers flattened and partially extruded from the primer pocket).
*p<0.05 Significant temperature-induced increase in muzzle velocity, one-way ANOVA, Holm-Sidak multiple comparison.
There is also a significantly higher velocity (p<0.05) with new N140 by two-way ANOVA and Holm-Sidak multiple comparison.
New Vihtavuori N140 on the left (Lot# 02.06.2021) and Old N140 on the right ( Lot# 01.12.2017)
The link to the full study in progress is below and is being discussed in a separate thread on this forum:
The newer N140 is reported (and advertised) to be “Temperature-stable” and to contain a “Decoppering agent.”
The new N140 appears to be less temperature sensitive below 68°F (20°C) than the old in the temperature range I tested. New N140 produces significantly higher velocity than the old at the same case charge with a 77 grain bullet. Both the new and the old N140 are moderately temperature sensitive above 68°F compared to Varget. With a case powder charge of 24.3 grains, both the old and the new N140 at 129°F (54°C) produce overpressure signs on primers (primers flattened and partially extruded from the primer pocket).
*p<0.05 Significant temperature-induced increase in muzzle velocity, one-way ANOVA, Holm-Sidak multiple comparison.
There is also a significantly higher velocity (p<0.05) with new N140 by two-way ANOVA and Holm-Sidak multiple comparison.
New Vihtavuori N140 on the left (Lot# 02.06.2021) and Old N140 on the right ( Lot# 01.12.2017)
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