In this video, Rex walks you through the process of logging your muzzle velocity variation (MVV) due to varying bore conditions and ammunition temperature variations. If you do not have access to Microsoft EXCEL, you may have to do this by hand. Either way, this video gives you the information you need to get started. The graph produced by this calculator will be the first page of your ballistics tables and will be used every time you calculate a new firing solution in the field. Failure to account for your MVV in the field will undoubtedly throw you off target. Evan at medium ranges, MVV due to ammo temperature can be huge! Your MV can change by over 200 fps due to varying ammo temperatures, and that will obviously have to be accounted for.

NOTE: Even with the use of propellants designed to have limited burn rate changes over different temperatures, MVV due to ammo temperature will STILL exist due to numerous other factors (see previous video).

Below is the link to the Ammo Temp MV Curve TABLES by TiborasaurusRex:

DOWNLOAD THE CURRENT VERSION by hitting the downward pointing arrow at the top left of the page and OPEN or SAVE the document so you can use it.

This calculator was created on Microsoft Excel by TiborasaurusRex using brn rate data
obtained from the “Ammunition Burn Rate Conversion Chart” figure in the book titled:
“The Complete .50-Caliber Sniper Course Hard Target Interdiction” by Dean Michaelis,
pages 175 and 176. ISBN 1-58160-068-2 This book is a great source of information, be sure to check it out at

All the music in this video was created by TiborasaurusRex, an unsigned artist.

Song Title: Wadi Watir, Minefield
Music and Lyrics by: TiborasaurusRex
Instrumentation and Vocals by: TiborasaurusRex
Recorded by: TiborasaurusRex


Xem thêm bài viết:

41 thoughts on “SNIPER 101 Part 59 – Ballistics Tables – Muzzle Velocity Variation (2/2)

  1. 1 i should make 3 000 crosses for 3 000 rounds on this paper ?
    2 how i would measure my velocity for every shot ?

  2. Great video, when you are documenting these muzzle velocities at different temps are you just taking on shot with a cold barrel? or are you taking several shots and averaging the velocity and then basing the data on that?
    Thanks for your help, these videos are incredible!

  3. Impossible to measure the surface temperature of brass with an infrared thermometer. Emissivity of shiny metals makes it notoriously hard to measure surface temp. Please help if you have any suggestions how to measure surface temperature of brass with the most accuracy, im currently having great difficulty doing this

  4. I know this is several years old…  Is there anyone who can post an updated link to be able to use the curve chart for the MV?  Thank you

  5. on this ammo temperature MV calculator, are the numbers above the 70 degree row, do you subtract that number from you're velocity of 2,971 or do add?????

  6. How does the temperature curve vary for ball powder (more temperature sensitive) vs. stick powder (less temperature sensitive)… Wouldn't the MV curve also depend on if you're using a ball or stick powder? i.e. flatter curve with stick.

  7. first off, Rex,you are a gentleman and a scholar, so generous of you to give out this service to those who are interested. Second, do the charts go down to say -40? the Yukon get chilly sometimes…

  8. Thank you so so much for doing this man, I can’t tell you how much I appreciate you, and the amount of time this took.

  9. New to this series and just binged my way through every episode to this point. Very informative and looking forward to the remaining episodes. Can't wait to get a chrony and start logging velocity/temp fluctuations. Which is actually what brought me here in the first place after noticing my POI changing from what I thought was established dope.

  10. Wouldn't different velocities coincide with different wind drift? I only ask because the chart he displayed only had one windage column?

  11. What amount of Muzzle velocity variation is acceptable from hand loaded ammo. The best I have been able to achieve is a deviation of 58FPS based on a sampling of 20 rounds. What's weird is that the same load through my Savage has almost 3 times more variation close to 110. At 100 yards the Savage is more accurate. Am I right to expect the Savage to not be as accurate at longer distances?

  12. Rex, this is my first post on your vids and I want to thank you on behalf of all the patriots for all the information you provide. Isn't ammo heating in the chamber unavoidable when you shoot a semi auto? How can we account for the expected ammo heating when we can't control when the round is chambered?

  13. I’m a deer hunter in upstate NY and normally shooting less than 100 yards. I’m not a long range shooter but I have experienced those first cold rifle shots being low at 100 yards in 30°F weather. Needless to say I found your videos “Sniper 101 parts 58 and 59 very interesting and it opened my eyes as to the potential solution to my problems. I realized what you were doing and I immediately down loaded the software “Ammo Temp MV Curve TABLES – TiborasaurusRex.xls“. 

    I’m also somewhat fluent with programing in Microsoft Excel and I saw the opportunity to improve the worksheet. The revised version consists of two tabs. The first accepts entries of test firings, calculates their respective 70°F MV’s and builds a reference table which best fits the entry data. The second tab provides the chart showing not only the MV vs Temp curve but also includes test firing data in scatter chart form.

    If you are interested, I would consider sharing my program with you. It’s the least I could do in return for sharing your knowledge through those great YouTube videos. Let me know.

  14. So did you go out to your range at those different temperature ranges (0-100) with a chronograph and that how you got you information for your curve or is there a calculator that can give you the different velocities at those different temperatures?

  15. Rex very nice series of video's, however I can't download the exel sheets via the links you've put above and below. Neither the sheets of part 63 and 64. Can you send them to me via mail plz? Thx

  16. What about us that live in Europe, we have everything here in metric system so feet per second and Fahrenheit doesn't tell much for us. And the conversions aren't always so exactly calculated. So how do I make my tables?

  17. stupid question but whee can I find data for like a 308 Sierra matching temp data to plug in if I don't have time to do all the testing?

  18. Keeping track (data) of actuals as rifle ages can be plotted using linear regression software (any standard statistics sw package) and you can get a new lines generated. The various statistic generated can give you an idea of the general fit of curve (i.e., how good the curve generated fits the actual data). Additionally, software can provide data to ID outliers.  Dang…wish I had these type of examples when I took statistics in college. Might have actually paid more attention… LOL.

  19. Hi.. First off Great Series. Keep the videos coming. Do you have the curve numbers for temps over 100 degrees F?? up to say 110 F??? … Texas gets hot from time to time…

  20. Hey rex for coloum 3 this is the formula i came up with for the phone app i made to shoot with it takes in ammo temp and bore temp

    put your ammo temp in for x and it will tell you MV
    *This is for my rifle will not work enless you have the same 70F MV as me

  21. Howdy Rex , hope you're getting better day after day , i got a question for you :

    You said using this calc every cartridge like a 30.06 ( so a good LR BC cartridge i suppose)  it's really similar to 50 BMG .
    Now my problem it's that i'm trying to use this calc for 22 LR and confronting it to other Ballistic Softwares both in pc and smartphone i get different MVV for temperatures , it's 22 maybe too far to use this calc?
    Thank you Sir!

  22. I didn't get a graph when I entered the MV data. When I clicked on the corresponding chart, I had lines with updated MV on the Y axis, but didn't get a line graphed out. Did anyone else experience this? Any help is much appreciated.

Leave a Reply

Your email address will not be published. Required fields are marked *