.30 cal 155grn tipped matchking supersonic range question

[Dan Rhodes]

Hello all,

Just wondering if any of you have tried out the 155 grain tipped matchking bullet much and could help me out with some real-world info concerning it's supersonic capability at different ranges. Sierra's website claims the G1 BC for this bullet is an amazing .519 @ 1900 fps and above, .490 between 1900 fps and 1600 fps,.420 @ 1600 fps and below. If I fired this bullet out of my rifle at say 3200 fps at say 1000ft. of elevation above sea level, I'm just wondering how far this bullet might travel while staying supersonic. Hornady's 4D calculator doesn't list this bullet as a choice in the drop-down menu, and their regular ballistics calculator gives far different numbers than the 4D because I'm guessing it doesn't factor in these changes in BC throughout the entire shot as the bullet loses speed. Are there any other calculators out there that might help me figure this out? Thanks for any advice I can get.

 

[JFrank]

Have you looked at
Federal Ballistic Calculator.

 

[Dan Rhodes]

no I haven't. I'll check out their website. Thanks

Have you looked at
Federal Ballistic Calculator.[/QUOTE

 

[Rtheurer]

JBM. is your friend. It will tell you what you want to know.
http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.1.cgi

 

[Rtheurer]

Looks like at 50* , 1000ft elevation, and 3200fps. it will just above Mach 1 at 1200 yards and will go into the Transonic stage right after that.

 

[Dan Rhodes]

Looks like at 50* , 1000ft elevation, and 3200fps. it will just above Mach 1 at 1200 yards and will go into the Transonic stage right after that.

Thank you for your reply on that! Curious to know what kind of ballistics calculator you are using to figure that out though. I know sierra has a very nice ballistics calculator program you can download for a price, but unfortunately I don't have the cash for it at the moment. I checked out the federal website and their ballistics calculator is even more rudimentary than the hornady standard calculator that doesn't really give a super accurate reading at ultra long range.

 

[Ned Ludd]

JBM Ballistics is an online [free] ballistics calculation website:

Simplified Trajectory - http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.1.cgi
Many additional tools - http://www.jbmballistics.com/ballistics/calculators/calculators.shtml

 

[Evan]

Not sure what your intent or level of experience is so I'll throw this out there: Even the most sophisticated calculators rely upon good data in. If you don't have accurate barometric pressure, temperature, altitude, azimuth, etc. for right where you're shooting, then all any of the calculators will do is get you close. At Mach 1 way out there, close could be plus/minus 10 ft. Enough to potentially see the splash and correct from there.

I wouldn't sweat the calculator. They get you close, then you develop your real tables from there by actually shooting.