Posted on 05/11/2011 7:14:14 PM PDT by Redcitizen
The “double the effective range” sounds a little like hype to me.
Isn’t this a lot like “double secret probation” at Faber College (Animal House)?
Can this round defeat cinder block walls at 25 yards? 50? 100? Or is that information “classified” because the laws of physics rule and it can’t do any of these things?
Once a mouse gun, always a mouse gun - I don’t care what kind of pellet it is.
To double the effective range of any bullet, you need to do one or more of several things to increase the ballistic coefficient:
1. Increase the sectional density. You can do this by either increasing the weight of the bullet or decreasing the diameter. Since we’re going to assume that we’re not going to decrease the diameter, we have to increase weight.
2. Decrease the bullet form factor, which is a mathematical way of saying “make the bullet longer, ‘pointy-er’ and blend the transitions from the nose to the body, and put on a boat-tail rear end for the trans-sonic transition...”
3. At the same time you’re increasing mass while sitting on top of the same cartridge, you’re going to quickly reach a point where you cannot achieve the same muzzle velocities with the heavier bullets as you can with the lighter bullets. For something like a .223/5.56, you will see your Vm go from about 3,000 fps to
Here’s a chart of .224 pills and their Bc’s:
http://www.extremeaccuracy.net/Scripts/prodList.asp?idcategory=57&curPage=1&sortField=description
OK, look at p1 and then the VLD pills on p2, especially the 80 and 90gr pills. You’ll see that the Bc’s for the VLD’s are twice that of the 55 to 60gr spitzer-style pills.
So such bullets exist. Why not use them?
Well, they’re so long that you either have to seat them well down into the case, or you can’t fit them into the magazine. If you seat a bullet down into the case, your case pressures go up, meaning that you have to back down on your powder load (and your velocities) in order to get the brass to contain the pressure.
4. There’s another problem with heavier & longer bullets: For heavier bullets, you need to speed up the rifling twist. For longer bullets, you might need to change the chamber throat. If you then switch back to lighter/shorter pills on the same rifle, you will over-spin your bullets (possibly causing fragmentation before they reach the target) and you’ll likely have accuracy problems from the longer leade (the jump from the case mouth to the rifling lands in the throat).
Can doubling the range be done? With a whole lot of caveats, “Yes.”
Can it be done in a rifle where the magazine length is a restriction on overall length of the round AND feed well enough for full-auto fire? Probably not. There are plenty of guys shooting 5.56 at 1000 yards/meters with VLD pills and doing a very good job of it, but they’re not shooting issue battle rifles, nor are they shooting full auto (or even burst fire).
Going back to the OP: Is putting steel into the core instead of lead going to increase the effective range? What mathematics I know of external ballistics says “no.” You need to get heavier, not lighter, bullets, longer bullets (in terms of calibers) and pointer bullets to increase the range. Then again, I don’t know what they might have done to the powder charge under the pill. A longer barrel with slower powder would help increase initial velocities with constrained pressures, but I don’t see that happening on issue rifles either. The trend is to shorter barrels, not longer.
If 0sama got a double tap to the head of 458, he probably ain’t got much left for facial recognition.
They are lying or totally ignorant of ballistics.
The denser the material, the higher the weight possible in a smaller diameter bullet, ie, the denser the material, the higher the sectional density, which translates to a higher Bc.
If we have two bullets of the exact same shape and exterior size, and one is heavier because it is made of denser material, that bullet will have a higher Bc. It will also likely have a lower muzzle velocity due to the increase in weight, but it will retain more of it’s initial velocity downrange than a lighter bullet that starts with a higher muzzle velocity.
Downrange, the kinetic energy of a bullet is given by KE = 0.5 m*v^2. As velocity falls off, kinetic energy declines as the change in velocity squared - meaning that you’re better off launching heavier bullets and retaining more velocity than launching lighter pills and bleeding your speed away.
Mass, however, doesn’t “disappear” as the bullet is on the way to the target.
My (leftie) green neighbor brought some "green" 2-stroke additive and some "green" chain grease for his new chain saw,,,
Guess what...it froze up after a some heavy use...
It used to be that a republican is a liberal who has been mugged...
Here we have a republican is a liberal who's chain saw froze up.
That leaves the problems you mentioned of case capacity, mag length etc.
62 replies and nobody has taken this to its logical conclusion...steel core is ‘copkiller’ and therefore ‘illegal’ to the peasants...so once ‘toxic’ lead is eliminated, we can use airsoft...
At the risk of being redundent to another post, won’t that steel core’s penatrating capability mean round might just pass through our Muslim friends?
How is the transfer of energy from round to Muslim affected?
At the risk of being redundent to another post, won’t that steel core’s penatrating capability mean round might just pass through our Muslim friends?
How is the transfer of energy from round to Muslim affected?
Is the US in its infinate wisdom going to be selling them to our so-called “allies” in this fight and then have them used against US personnel?
Well the current m855 has a steel core core and those rounds already just pierce targets. The new M855A1 rounds don’t transfer any more energy than the M855 rounds.
Turn off the wind. Arrange for all our wars to be fought inside railroad tunnels or reallllly long airplane hangers, instead of Afghani mountainsides and hills.
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