Meaning of "A1" after a caliber?

[John_M]

What is the meaning of A1 after .223 Rem and other calibers? Searched the FAQ's on this site and Google to no avail. :confused:

[drybean]

Ackley Improved,shoulders are 40 degrees & less body taper

or so i have been led to belive

drybean

[fgw_in_fla]

A.I. not A1...

Ackley Improved . Read all about it the history of it in Wikipedia....

Interesting info.

http://en.wikipedia.org/wiki/Ackley_Improved

[Blue Avenger]

http://img.photobucket.com/albums/v675/gcidso123/savage/reloading/201_5028.jpg


right and left are .308 cases necked down to .243 win. Center is a .243 blown out to AI. You can see the case now has more internal space for more powder. Speed may not go up much on some cases. but the sharper shoulders help slow the growth of the case from repeated firing. The pressure inside the case caused the brass to flow and the only free place it has to go is towards the neck. Sharper angles are rumored to slow the flow and redirect the blowtorch effect of the powder flame.

[John_M]

Thank you gentlemen, all, for the accurate and precise information. I guess the reason I was unable to find the info on Wikipedia is that I was substituting "A one" for "A.I."

Blue Avenger, you have provided an excellent example of why "A picture is worth a thousand words".

Good luck and best wishes to all.