My kind of math project.

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11 years 8 months ago #23701 by Siscowet
My kind of math project. was created by Siscowet
My son has decided for his project for statistics class that he is going to plot the trajectory curve of my most recent reloads for my 5.56. We have a trajectory curve for xm855 rounds which should be pretty close, so we are headed to the range this weekend with 100+ rounds and do plots at 25, 50, 100, 150, and 200 yards and project the trajectory curve from there. I knew there was a reason for that course!
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11 years 8 months ago - 11 years 8 months ago #24035 by Siscowet
Replied by Siscowet on topic My kind of math project.
He decided the above project was a little ambitious for a statistics class, and more of a trigonometry question. Instead, he decided to compare a factory Lake City XM855 Load to a Hand load with the xm855 bullet. He shot 11 five round groups of each for 22 total targets, and threw out the worst one from each group.Interesting results. The average group size at 25 meters was only .1 smaller for the hand load, showing that the standard military bullet has only so much accuracy potential. Consistency wise, though, the hand load won hands down, with a sample variation of only .17 between the smallest and largest groups while the factory variation was .38 between groups. All shooting was done with a Colt HBAR, 1 in 7 twist. Hand Load was 24.9 grains of reloader 15 with a CCI small rifle primer and Remington cases. Front bench rest and rear sand bag. Basically proved that good hand loads are more consistent than factory loads with the same bullet, at least mil spec bullets from Lake City. Wasn't the most scientific endeavor, but a good excuse to shoot up a hundred rounds or so. Pictures of 2 of the handload groups below. We had a 10 to 15 mph crosswind, and did not finetune the sights for 25 meters, since we were more interested about the diameter of the groupings.



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Last edit: 11 years 8 months ago by Siscowet.
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