What Is The Fastest, Flattest Shooting Shoulder Fired Rifle?

[M-Tecs]

The OP didn't address intended usage and yardage. Light for caliber bullets are easy to push fast but they shed velocity quickly so as the distance increases what is the fastest and flattest changes.

[357Mag]

Doug -

Howdy !

I wanted to pass along a few quotes and data inputs from ballistician Homer Powley, inventor of the " Powley Computer ". These were gleaned from an article called " The Powley Papers ", which appeared in the " Guns & Ammo 1974 Annual ".....

" The main purpose of a gun is to deliver energy at a distance ".

" With a particular cartridge, lighter bullets ( if at least 2.5 calibres long ) always have less drop and less remaining energy than heavier bullets which exhibit more drop and more remaining energy; with the same bullet shape ".

Powley included a chart that allowed one to estimate the expansion ratio ( ER ) of rifles having 28" barrels, and varying calibres of . 20 through .50; w/ a max
( IMR ) powder charge of a notional 100gr. This chart only listed Expansion Ratios as low as 4, and as high as 14. A low ER value of 4 indicating less efficiency in the conversion of burning powder into kinetic than would a higher ER value; such as 6. Powley used IMR powders for his 1960- 1961 Powley computer, likely because they were the dominant brand back then ( I.E. duPont de Numours ). Powley used an averaging of the IMR powder's bulk densities, a value which I believe was .86 .

From what I can tell, a .224" cal wildcat holding 75gr of IMR powder, would have an ER of 4.
A 6mm wildcat holding 85gr of IMR powder, would have an ER
A .25" cal wildcat holding 94gr of IMR powder would have an ER of 4.
All the above based on 28" barrel length.
*** Powley apparently did not feel compelled to chart cartridges that were so large in capacity as to produce ER's lower than 4. ***

Above the powder charge levels in the 3 calibres listed, significant amounts of the powder charge would end contributing less and less to the practical production of
useful velocity/ bullet energy.

I DK if this helps you any ?


With regards,
357Mag

[357Mag]

OOPS -

Correction to previous.....

" A 6mm wildcat holding 85gr of IMR powder would have an ER of 4 ( 28" barrel )


With regards,
357Mag

[Tripplebeards]

When I think flat shooting I always think what shoots the flattest to 400 yards. Most varmint calibers loaded at 4200 fps will shoot pretty flat to 400 yards. Usualy sighted in 1.5"
high at 100 yards drops around 2" or so at 400 yards. After 400 yards my crosshairs have to be raised above "fur". Anything father is not predator hunting to me and just taking long range "hail mary" pokes when spotting animals.

[17nut]

Many moons ago the airforce did a rifle on a 20mm case necked down to .50 cal.
Long time since i read it but was for testing jet cockpits simulating air to air speeds on conventional bullets.
Seem to remember something like 5000fps with a 650grain bullet.


Do i win a price?

[Tripplebeards]

I want one!

[Lloyd Smale]

flattest shooting rifle ive owned is a 300 rem ultra mag. But heads up. You don't want to shoot it without ear plugs even once on a deer. Close second is my 7 stw.