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6/21/2017 8:25:40 PM
Posted: 6/5/2012 11:18:32 PM EDT
Please bear with me, this is my first post and I am still getting used to the features of this board.

I am looking for a chart showing the distance a standard supersonic 300 blackout can go before dropping. I am not factoring wind in this equation. I would also like to know joules or force at drop point.
As an example, for a given round of standard supersonic 300 blackout (no reload or special stuff), how far does the round go before dropping with a 6 inch, 8 inch, 10 inch, 16 inch, 20 inch barrel and so forth. What is the force of the bullet.

If there is a link please let me know.
Link Posted: 6/6/2012 5:15:13 AM EDT
Link Posted: 6/9/2012 4:58:56 AM EDT
The most accesssible general ballistics calculator I have found is at URL:

http://www.hornady.com/ballistics-resource/ballistics-calculator

You can run parametrics with it. Your basic problem is finding out the muzzle velocity generated by the different barrel lengths
Link Posted: 6/9/2012 6:09:49 PM EDT
I find this ballistic chart pretty easy to use too... If you don't know the BC of the bullet, on the left is a little calculator which can give you a good estimate based on weight, diameter and bullet type

http://www.handloads.com/calc/

Link Posted: 6/10/2012 6:13:41 AM EDT
heres some muzzle velocity data for you...

Link Posted: 6/10/2012 7:50:35 AM EDT

Originally Posted By abinok:
heres some muzzle velocity data for you...

http://sphotos.xx.fbcdn.net/hphotos-ash4/412260_343799122333216_617473682_o.jpg

Two questions...

What is the significance of the 110gr Barnes loading? Is that a pretty standard round? What makes it comparable to M193?

Also, are the highlighted muzzle energies chosen to show the common 5.56 barrel lengths and the comparable length required for the same energy out of a 300BLK?
Link Posted: 6/10/2012 11:22:04 AM EDT
[Last Edit: 6/10/2012 11:22:16 AM EDT by abinok]
The Barnes is a purpose built bullet, designed specifically for the 300 blackout. It is designed to expand at lower velocities... down to 1300fps, and its longer tip and ogive enhance feeding in ar rifles.
I picked it because there is lots of data on it in a variety of barrel lengths. Hornady 110 vmax can be driven a bit faster, and has a comparable muzzle velocity. The highlighted sections correlate muzzle energy from a given length barrel, for both loads. While I can't comment on the exact reason the m193 was chosen for this particular chart, I would assume its because it offers the best average performance across the entire spectrum of barrel lengths, and because most readers will be familiar with the load. Mk 262, M855 or even XM777 will show the same relationship until you get to radically heavy or light projectiles.

Put another way, a 45gr loading will show less fps lost per inch at shorter lengths compared to a 77gr loading, and the energy will follow. While the barnes 110 loading is one of the lightest for the cartridge, this bullet weight will probably be the most popular weight for supersonic loads... just like 55gr 556.

You might head over to http://www.300blktalk.com/forum/ for more info, if you're interested.

Of course with the caveat that you will find more fanboys there than here.
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