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Join Date: Oct 2005
Location: In the Woods Pa
Re: ackley lmproved
The Ackley Improved AI is a wildcat. No factory ammo nor chambering available.
The word improved means you can shoot the factory ammo in it. Which isn't accurate but OK and it makes the case then form fired to the AI shape.
An AI improved case is one that was developed by P. O. Ackley. A respected gunsmith having a shop in Trinidad CO. He wrote for Guns and Ammo and shooting times. Now deceased.
P.O. had the cases made with the same shoulder dimensions, so they headspaces properly with thefactory case. T significant thing is to make a generally straight wall case body, this increases powder capacity DEPENDING on the factory case in question.
Factory cases with generally little body have little advantage being AI (regardless of what people say). Factory cases with significant body taper will have significant increase case powder capacity nad therefore more velocity. The 30-40 Krag is the perfect example of a good AI case. The 300 h&H is another cartridge that increases its capacity by the AI process, as it too also has a ot of body taper. And while these were worth wile in 1960s, today one can get a 300 win mag or a 300 rum and get better velocities than with the old AI improved cases.
Most modern cases like the 243, 308, etc have little increase in powder capacity by reducing the body taper. By comparison the 280 AI gives one extra grain o h20 in case capacity. Hardly worth the effort. so one might say, where does the extra velocity come from?? We AI cases are wildcat so there is no real standard and most are loaded above the pressure in the factory case.
Improving (AI) modern factory cartridges generally give about 150 fps or less at the same pressure. each shooter needs to decide if it is worth the extra activity and expense.
AI cartridges were more significant when we did not have all the factory choices we have today. Today if one wants more velocity than a standrd 280, ,one merely buys a 7 mag. and uses the sved $$$ for more ammo to shoot.