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A Histogram of Hornady 180 gr 10mm XTPs

BigDanSBigDanS Senior MemberPosts: 6,973 Senior Member
My Kel Tec Sub 2000 .40 project continues. Today I purchased a box of 100 Hornady 10mm / .40 cal 180 gr XTP's from Bass Pro Shops.

I decided to weigh and separate the box just as I did the Berry's 165 gr bullets, and here is the result of the entire 100 Hornady XTPs:

EF4E8C0A-DA1E-4030-8B42-9FC9A39E0199_zps1nfigm6d.jpg

in my opinion that is a pretty significant variation. Certainly it isn't just bullet weight consistancy that makes a bullet fly straight and true, so I am reserving my judgement for the range.

I loaded a full test batch of rounds from 6.8 gr to 8.0 gr of Longshot in .2 gr increments. I threw out the lowest weights and started at 179.7 gr and loaded sequentially to 180.6 gr, keeping each test batch of bullets loaded within .1 gr over the same powder charges. I have enough to run accuracy tests, chronograph and water jug penetration tests, that I am hoping the weather will cooperate this week.

D
"A patriot is mocked, scorned and hated; yet when his cause succeeds, all men will join him, for then it costs nothing to be a patriot." Mark Twain
Alcohol, Tobacco, Firearms and Explosives.... now who's bringing the hot wings? :jester:

Replies

  • Big ChiefBig Chief Senior Member Posts: 32,995 Senior Member
    You get bored or run outta bullets to evaluate...........come on by I got several thousand of all kinds you can sort and categorize for me :tooth:
    It's only true if it's on this forum where opinions are facts and facts are opinions
    Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
    I'd rather have my sister work in a whorehouse than own another Taurus!
  • Big ChiefBig Chief Senior Member Posts: 32,995 Senior Member
    So in retrospect the Berry's Bullets were pretty consistent. Seems slight weight variations don't make a hoot in handgun bullets. Hornady are some of the best on the market.
    It's only true if it's on this forum where opinions are facts and facts are opinions
    Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
    I'd rather have my sister work in a whorehouse than own another Taurus!
  • Big ChiefBig Chief Senior Member Posts: 32,995 Senior Member
    Seems concentricity and how well handgun bullets are made is the key.
    It's only true if it's on this forum where opinions are facts and facts are opinions
    Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
    I'd rather have my sister work in a whorehouse than own another Taurus!
  • breamfisherbreamfisher Senior Member Posts: 13,490 Senior Member
    BigDanS wrote: »
    I loaded a full test batch of rounds from 6.8 gr to 8.0 gr of Longshot in .2 gr increments. I threw out the lowest weights and started at 184.7 gr and loaded sequentially to 185.6 gr, keeping each test batch of bullets loaded within .1 gr over the same powder charges. I have enough to run accuracy tests, chronograph and water jug penetration tests, that I am hoping the weather will cooperate this week.

    D
    What do the bolded weights mean? Is that bullet + powder charge?
    Overkill is underrated.
  • BigDanSBigDanS Senior Member Posts: 6,973 Senior Member
    What do the bolded weights mean? Is that bullet + powder charge?

    If you look at the histogram, bullets weights run from 179.1 to 181.1. That's a typo on my part. It should have been 179.7 to 180.6. My senior brain was thinking 165's, translated it to 185's when I was working on 180's... Too much math, too little sleep.

    Thanks, I will correct it.

    D
    "A patriot is mocked, scorned and hated; yet when his cause succeeds, all men will join him, for then it costs nothing to be a patriot." Mark Twain
    Alcohol, Tobacco, Firearms and Explosives.... now who's bringing the hot wings? :jester:
  • CHIRO1989CHIRO1989 Senior Member Posts: 12,430 Senior Member
    Do you think the variation in weight is going to make a difference at the ranges the bullet was designed to be shot at?
    I take no pleasure in the death of the wicked, but rather that they turn away from their ways and live. Eze 33:11
  • breamfisherbreamfisher Senior Member Posts: 13,490 Senior Member
    So running your data, you have a median of 180.3, mean of 180.237, and standard deviation of 0.445778. Coeffecient of variation is 0.2473. Highest value is 0.6 % of your nominal value. That's pretty tight manufacturing, really.

    Further, unless your scale was isolated from ANY wind/air effects in weighing, along with possible vibration and other influences, the variation you see may be instrument/environment-induced or -inflated. Not knowing the actual precision of your scale, whether it was recently calibrated, what the manufacturer considers "acceptable" variation, and other factors also bring the spread into question. One grain is about 0.065 grams. To measure that level of actual precision, scales are usually in a box to make sure the air is still, perfectly leveled, and isolated from vibration.

    My opinion: what you think is too much variation really isn't.
    Overkill is underrated.
  • BigDanSBigDanS Senior Member Posts: 6,973 Senior Member
    So running your data, you have a median of 180.3, mean of 180.237, and standard deviation of 0.445778. Coeffecient of variation is 0.2473. Highest value is 0.6 % of your nominal value. That's pretty tight manufacturing, really.

    Further, unless your scale was isolated from ANY wind/air effects in weighing, along with possible vibration and other influences, the variation you see may be instrument/environment-induced or -inflated. Not knowing the actual precision of your scale, whether it was recently calibrated, what the manufacturer considers "acceptable" variation, and other factors also bring the spread into question. One grain is about 0.065 grams. To measure that level of actual precision, scales are usually in a box to make sure the air is still, perfectly leveled, and isolated from vibration.

    My opinion: what you think is too much variation really isn't.

    You are likely correct. I am just adhering to my rifle load philosophy. Make them as close to the same as possible, since these really are not handgun bullets. And thanks for the statistical analysis. FWIW my scale is my Lyman Gen 6 electronic scale. I calibrate every day it is used.

    D
    "A patriot is mocked, scorned and hated; yet when his cause succeeds, all men will join him, for then it costs nothing to be a patriot." Mark Twain
    Alcohol, Tobacco, Firearms and Explosives.... now who's bringing the hot wings? :jester:
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