[We7det_el_qetal_ra3d]

Bullet has a weight of 100 grains, it's basicly a tungsten core with a steel jacket.

cartridge is .22-243 to give a velocity of around 3000 FTPS

what do u think of that?

 

[We7det_el_qetal_ra3d]

SD=0.287 approx.

 

[mele]

BC??

With a .223 it would require mega fast twist rate....

MEL

 

[We7det_el_qetal_ra3d]

if u could help me with that Mel that would be great coz I can't figure out a BC for that Bullet, and if u could help me with estimating a twist rate I would greatly appreciate it :wink:

 

[muzzleblast]

heh, 1 in 5, maybe?

 

[spade]

heres the problem with that, im not sure if it would happen on a 22-243 but ive seen it on a 22 hornet and 204 ruger before. IF you load too hot, the bullet actually tears itself apart on the way to the target. Its pretty weird when your shooting at 50m and cant get anything on paper. Spotter keeps looking over at you and going " dood, why do i keep seeing this poof?".

 

[mele]

The BC needs to be calculated using actually ballistics data from the range. Some software can guesstimate a value, but its not official until you calculate with live data. (it takes at least two chrono's).

The twist rate is probably 1:5 or 6 maybe.

MEL

 

[spade]

just out of curiosity, how long would this bullet have to be to obain 100 grains? i cant see you seating it really deep cause theres a need for a proper powder charge.

 

[mele]

He said it would be tungsten core which means it physically would not have to be as large to get that weight.

MEL

 

[OLD TOUCH]

22-243vs 22-250

I have not looked to see just what the density of toungsten is but why not just take a 22-250 60grs HP at 3600fps and work up a load for your toungsten rounds from there, you can readily get the cases for the 22-250, also would not the barrel life be very short for a 1 in 5 twist even if it is only traveling 3000fps, and for those that just want a 100gr bullet traveling 3000fps go to a Hornady Spire Point#2450 in your 243 with 47.4 grs of WIN 785 powder or 48.2grs of H450 for about 3100fps.
But then there are those out there that just want to have a bullet that noon else has, why do you want such a slow Round ? Spade says Quote "
ive seen it on a 22 hornet and 204 ruger before. IF you load too hot, the bullet actually tears itself apart on the way to the target."
I personaly have never seen one blow apart but both of those rounds travel at speeds fast enough to disintigrate the bullet if they even hit a bug in flight or a blade of grass.
Rusty[/quote]

 

[6.5shooter]

If i understand it right, the lead core copper jacketed bullets can and will blow up in flight if you load too hot. Strait lead bullets will do it even worse. This is why the copper jacket was introduced. Ive never personally seen it, but my dad did it once with a 22-250.

Tungsten has a density of 19.32 g/ml while lead has a density of 11.35 g/ml.

This bullet sounds good in theory, but are you going to try and put a copper jacket around it? Lost river ballistics technologies completly ditched the copper jacket so they wouldnt have to worry about the jacket seperating from the core. This is what gives their bullets such high BC's (high density metal). Perhaps the solution to the jacket would actually be a moly coating? Ill do a little more digging and see what i can find about tungsten.

Also there is a thread in the forums (cant remember where) somebody gave us the formula for calculating twist rate. The problem you would run into with this formula is 1. i dont know if it would work with a higher density metal and 2. you have to have the length of the bullet.

Just my $.02
Chris

 

[madgunsmith]

With such a hard bullet material, I'd worry about pressures going crazy.

To calculate barrel twist, use the Greenhill formula.


The length of the bullet in calibers multiplied by the twist rate in calibers should equal a constant, the number 150.


Mad

 

[JRP3]

Tungsten is also a fairly brittle metal. Could pose alot of problems I would think, but I am no metallurgist.

J

 

[AK]

Although I am by no means qualified to talk about Tungsten, it was used as armour-piercing ammunition penetrator-rod material. So perhaps it is the manufacturing process that defines how brittle the material is with regards to Tungsten?

 

[We7det_el_qetal_ra3d]

When i posted this thread i didn't expect so much help,

but thanks guys u prooved me wrong :wink:

i'm glad i registered on this forum.

 

[We7det_el_qetal_ra3d]

When i proposed this cartridge i didn't have in mind civilian use, i proposed it as a government project to introduce a bullet suitable for urban ops with penetrating level IV body armour in mind, and because i know the bullet would be under a lot of stress that's why i proposed a steel jacket, but all that sounds good in theory, but i think numbers will be the first step in determining the feasability of such a cartridge for SOF.

 

[We7det_el_qetal_ra3d]

I think this might be interesting

http://www.angelfire.com/art/enchanter/pigboard.html

 

[mele]

Facinating reading.

MEL

 

[genen]

I think this might be interesting

http://www.angelfire.com/art/enchanter/pigboard.html

The only bit that I would question (and the author did too) is the whole 'accelerating after exiting the barrel' part.

1)Even IF there is a column of expanding gas behind the bullet, the amount of energy transfer from that gas to the bullet would be miniscule compared to how much is transferred to surrounding air.

2) at the velocity of the bullet, the amount of energy required to increase velocity due to air friction would be quite large.

Anyone else with a physics background care to chime in?

 

[We7det_el_qetal_ra3d]

Gen it doesn't take a genius to figure out that you are right

that's why we use a barrel to confine gas expansion into one direction, so that part about velocity increase after exit is crap.

totaly agree it's not realistic