RichZ, I get you and agree that bullet drop has little to do with "repeatable precision placement" when it comes to the seemimgly over used term "inherent accuracy". Bullet drop, when all factors are equal, will be a measurable and there after predictable effect based on drag and gravity alone. This can be compensated for and reduced to a practical zero variable in some few ways; first, a laser range finder and ballistics chart for your given load. Second, shooting a known distance coarse and using the same ballistics chart. Other factors to be compensated for in reducing the variable of drop would be: wind (leading or following), temperature, pressure, humidity, bullet wieght and ballistic coeffientcy of the projectile. All of these factors regard to drag and can be measured and there by have their effects on bullet drop be compensated for and reduced to, as I said, a "practical zero".

Therefore, we can eliminate bullet drop from the equation that we are trying to "inherent accuracy". Wind as a crossing effect is more responsible for a left/right stringing and we could reduce this variable by measuring a vertical group size with regard to "inherent accuracy".

We can also eliminate terminal ballistics from the equation. The expansion rate, wound channel and bullet path are irrelevent. Repeatable shot placement is all that matters and after the proj. peirces the paper/skin, terminal ballistics begin.

We are left with internal ballistics and external ballistics.

External ballistics are effected mostly by the two aforementioned factors: drag and gravity. The true relationship of these factors was eventually determined by the inventor of the ballistic pendulum, Benjiman Robbins. Sort of a crude chronograph, with it he was able to find the remaining energy of a projectile after a known distance and knowing the wieght of the proj. determine the velocity at impact. The ratio is a whopping 85:1! That is air drag has 85X the effect on a proj. than gravity. And ever since, ballisticians have been trying to decipher the most perfect and truest effects of drag on trajectories. These effects are stated in part above: temperature, pressure (altitude), humidity, distance to target and leading or following wind.

NONE OF WHICH I feel relate to the basic design of a cartridge or it's "Inherent Accuracy"!

Except for two factors... Sectional density and ballistic coefficient. A small mass with large cross section (pingpong ball) will be more effected by drag than a similar shape of higher density; a lead pingpong ball will fly further and a hollow, plastic one. Simply put, the ballistic coeficient (C= w / (i x d<2>)) is the wieght/("form factor"x diameter <sq>). All this means is finding out "how much" drag effects and certain bullet shape. i.e.- "long and pointy" IS better! The basic cartridge design that can accomidate bullets of prefered S.D. and B.C. are MORE INHERENTLY ACCURATE.

That leaves internal ballistics!

The firing pin ignites the primer causing an explosion that, in turn, ignites the powder developing an expansion of burning gasses. These gasses develop more preasure which increases the burn rate of the powder until the gas pressure overcomes the friction of the crimp that is holding the bullet. Yeah... yeah... WE KNOW!!!

The rest of it; the bullet passes the "leade" and engages the rifleing, pressure is still building, the bullet begins rotating and accellerating and pressure is still building until, at some point, the pressure begins to decrease due to the expanding volume of the bore behind the bullet. This continues until the bullet leaves the muzzle. However, this pressure wave is still there and can effect the bullets flight path even after it leaves the muzzle (that's why my M1A flash hiders are taper reamed to M21, MTU specs... but that would be external ballistics

).

Discounting rifle to rifle variations in the cut of the bore and lands and crown of the muzzle, which in thier way DO effect accuracy, but NOT the "inherent accuracy" of any cartidge design, we are left with the ignition, detonation and subsequent build up of pressure of our powder as it relates to case shape (internal and external), primer consistancy and flash hole size and uniformity. Primer consistancy is NOT case design and can be dropped from the equation as a variable. Yes, it

*will* effect your accuracy, but should NOT be considered as a variable w/regard to "inherently accurate cartridges" because you can use the same primers in any two cases and have only the variables of flash hole shape and size and case shape and size left as unique.

So there it is! Case shape and size and flash hole shape and size as the remaining design factors that contribute to any ONE cartridge being MORE accurate than any OTHER. As I said above:

Now if they had gone on about "a shorter powder column gives a more consistance burn pressure from shot to shot.", as in the case of the actual cartidge design of the .22PPC, 6mmPPC, or the new crop of short and super short magnums, I could have bought it!

And for me, that's about all there is to "inherently accurate cartridges"...

anodes.

btw, Rich, I put a recliner in my Ivory Tower...