Site Notices
9/23/2014 4:41:23 PM
Author
Message
Amphiprion
Offline
Posts: 1
Feedback: 0% (0)
Posted: 6/6/2012 3:18:32 AM
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.
Eric802
It's not the years, it's the miles...
Online
Posts: 17412
Feedback: 100% (15)
Link To This Post
Posted: 6/6/2012 9:15:13 AM
It starts dropping as soon as it leaves the barrel. If you want a ballistics chart showing how far it drops at various distances, you'll need the muzzle velocity and ballistic coefficient of the bullet.
There is no such thing as too much money, too much sex, or too happy on the happy switch. - TRG

I have to return some videos.
Phantom30
Offline
Posts: 4
Feedback: 0% (0)
Link To This Post
Posted: 6/9/2012 8:58:56 AM
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
imaguy3
Offline
Posts: 33
Feedback: 100% (1)
Link To This Post
Posted: 6/9/2012 10:09:49 PM
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/

abinok
Offline
Posts: 628
Feedback: 100% (4)
Link To This Post
Posted: 6/10/2012 10:13:41 AM
heres some muzzle velocity data for you...

felrom
Fighting Naturalist
Offline
Posts: 2260
Feedback: 100% (3)
Link To This Post
Posted: 6/10/2012 11:50:35 AM

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?
The NFA's days are numbered. One day I will walk out of a gun show with a new machine gun in my hands. No tax. No wait. Present CHL. Hand over cash. Fill out a 4473. And leave.
abinok
Offline
Posts: 629
Feedback: 100% (4)
Link To This Post
Posted: 6/10/2012 3:22:04 PM
[Last Edit: 6/10/2012 3:22:16 PM 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.