This is taken from an article by Frank Haertlein, former President CVCA(California Varmint Callers Association), entitled "Accuracy Velocity".

Has anyone every read this article?

Basically, they did an extensive experiment to determine how velocity effects accuracy using several different bullet combinations. Their findings show a "sweet spot" at a a particular velocity.

They also conclude thet "sweet spots" can be found at other velocities. Sort of like nodes on a sinusoidal wave.

Has anyone else heard or done this?

[url= http://"http://www.hunt101.com/?p=48473&c=556&z=1"] [/url]

[I'll try to post a link if I can find one.]

Have a good one!

Kenati

This isn't anything new. These "sweet" spots are due to barrel harmonics (vibrations) that occur when you fire the rifle. The theory is that you want to find a load where the bullet is exiting the barrel a the end of a harmonic.....where the vibration is changing direction and barrel movement (from the vibration) is the slowest.

Barrel time can be affected by many things (the program QuikLoad calculates this) including the type and amount of powder, the bullet (bearing surface mostly) and of course the primer used. You can plug these various factors into QuikLoad and see how barrel time changes.

My .308 M7 was shooting .7 MOA with groups opening up to 1.3 MOA with just .01" change in seating depth both shallower and deeper.

That was a sweet load, with 165gr Partitions.

Though it was under book max the primers were well-flattened (probably due to flashhole deburring) so I decided to back off a half grain of powder and it took me back to square one.

This idea of a "sweet spot" seems to form the basis for the Browning and Winchester B.O.S.S.
systems. I agree it works and works well. The only problem is you have to experiment enough to find the sweet spot for each bullet you use. The findings from one bullet are not transferrable to another. I've never felt up to that much testing. Best wishes.

Cal - Montreal

I THINK MOST PEOPLE FEEL THE "SWEET SPOT" EXIST BUT I COULD NEVER FIGURE HOW YOU COULD MAINTAIN A CERTAIN VELOCITY. I HAVE NOTICED VELOCITY CHANGES OF 150FPS WHEN THE TEMPT. DROPS IN WINTER AFTER I WORKED THE LOADS UP IN THE SUMMER. YOU CAN HAVE THIS LEVEL OF VELOCITY LOSS WITH ONLY A DROP IN TEMPT OF ABOUT 50-60 DEGREES.?

BR5555...turn off your CAPS please.