PUBLIC Forums => Public Forums => Forensics => Topic started by: Michael Haag on November 21, 2012, 09:14:54 AM

Title: Military Subsonic Bullets
Post by: Michael Haag on November 21, 2012, 09:14:54 AM

http://www.cnn.com/2012/11/20/tech/innovation/subsonic-bullets-wired/index.html?hpt=hp_c3 (http://www.cnn.com/2012/11/20/tech/innovation/subsonic-bullets-wired/index.html?hpt=hp_c3)

Title: Re: Military Subsonic Bullets
Post by: Dan Alessio on November 21, 2012, 04:43:59 PM

"Breaking the sound barrier also pretty much negates the use of a sound suppressor, or "silencer," which the special forces would likely want to use"

"Normally, a bullet expands -- or obturates -- to the size of its barrel after being fired"

Wow.

Title: Re: Military Subsonic Bullets
Post by: rwalker on November 23, 2012, 10:02:10 AM

I reference these polymer cased cartridges and its continued development in my book, there some different approaches from different "players" out there. 
 
Walker.

Title: Re: Military Subsonic Bullets
Post by: Justin Bechaver on November 26, 2012, 11:28:53 AM

I second your "Wow" Dan,

However, I met these folks at the SHOT show last year.

http://www.pcpammo.com/index.htm (http://www.pcpammo.com/index.htm)

Title: Re: Military Subsonic Bullets
Post by: Axel Manthei on November 26, 2012, 12:36:52 PM

For those who have CartWinPro:
Check for "5.56 Synthetic" in the calibre database and follow the relation link to the cartridge.
You can find the data and pictures of the 5.56 SCF Steyr
With 4855 fps this is the last cartridge/ firearm I would try to put a silencer on  :)


Axel

Title: Re: Military Subsonic Bullets
Post by: winterh on November 27, 2012, 05:37:00 PM

Ok, Lets look at this from a differant perspective. In order to be relativly silent the velocity must be kept to a minumum, lets say 950 fps. In order to get the desired results you must increase the weight of the bullet and at the same time maintain stability. In order to maintain stability we need a projectile that is perfectly balanced at any rpm. In other words your bullet must resemble in some way the configuration of a football. An object that will fly with rotational stability at a variety of velocities. Imbalance is the culprit...HW

Title: Re: Military Subsonic Bullets
Post by: Aaron Brudenell on November 27, 2012, 05:41:42 PM

Another approach is to use a bullet that's front heavy--I believe a forward center of gravity will enhance stability as well.

Title: Re: Military Subsonic Bullets
Post by: winterh on November 28, 2012, 08:04:32 PM

In the case of say the 7.62x51mm. If one was to seat a 168gr. MatchKing backwards with the base forward and the hollowpoint to the rear the same result would be had, I would think...HW

Title: Re: Military Subsonic Bullets
Post by: Jerryp on February 13, 2013, 05:27:14 AM

Winteh

Wouldn't the heaver bullet be longer and require a faster twist rate?

Title: Re: Military Subsonic Bullets
Post by: Paul Murphy on February 14, 2013, 09:50:28 AM

If you turn some bullets around and seat them base forward it defnitely improve penetration.  Years ago we did the experiment with 150 grain 7.62 x 51mm Nato FMJ ammunition.  If you shoot at a falling plate (12" x 12" steel about 1/2" thick) the bullet will knock the plate over and mak a small indentation - if you turn the bullet around it will "punch" a neat round hole throug the steel plate.

Title: Re: Military Subsonic Bullets
Post by: Jerryp on February 14, 2013, 12:01:20 PM

Maybe we should invent wad cutters for rifle cartridges?

Title: Re: Military Subsonic Bullets
Post by: Axel Manthei on February 15, 2013, 10:53:22 AM

Too late, already invented by Dynamit Nobel/RUAG!  :-0
Short range practise ammo in .50 BMG
See collection record M3006 in CartWinPro

Axel
 (http://www.cartwinpro.com)