What exactly is Ackley improved??? (I may have spelled that wrong, Im not sure of the correct pronunciation)

AI= Ackley Improved, Years ago there was a gunsmith (P.O. Ackley) that wanted more performance from standard cartridges and still use the same brass. His idea was to leave the shoulder neck junction in the same place on rimless cartridges so a factory cartridge could be fired formed in the "Improved" chamber. To "improve" the chamber he straighten out the case walls to a minumum taper and put a sharp 40* shoulder on the case. This "opened" the case capactiy up for more powder.

Here is an example of an AI 223. As you can see the middle cartridge has the neck shoulder junction is the same place as the other cartridges but the case is larger in the body and the 40* neck makes the case have more lenght capacity.




Some of the Early cases that had a lot of body taper like the 30-30 and the 22 Hornet really gained performance by going to the "improved" version. But cases that did not open up much from the standard design really don't gain enough performance to justify the extra powder burned for the slight gain in performance.

I have a 30-30 AI here if I get a chance I'll take a photo and post it you will see the 30-30 really gains case capacity in the AI version.

cool on the photo tig! i was wishin i had one to show. i definately like the 30-30 version.

Does it shorten the live of the brass by fire forming?

Very good question Rupe.

You are suppose to use the minimal powder charge when fire forming to help will case life. I will have about a 50% success rate on the on the 7-30 Waters if I use a normal powder change to fireform. If I use a minimal powder charge I have about a 95% success rate.

Some of the improvements on wildcats actually have better a life span. One “improvement,” on some of the cartridges is that the case itself has no taper. That will actually help the brass life. It will also make the case more efficient from what I have read. After the case has been fire formed it shouldn’t make a big difference.

Food for thought, a lot of people will make wild cats from strong cases like JDJ's based of the 444 brass or the 475 Lin. off the 45-70 Gov. Others will use 375 Win brass on the 30-30 Akl or the 7-30 Waters.

The term "minimal powder charge" is sort of subjective. You have to use enough powder to fully form the case in one shot, however much that is. Nothing says you can't use them for more than practice either. I've killed several deer with rounds I was fireforming.

HI there Hunlee hear!!!!!Hunlee has never see a 223ai or a 30-30ai but they must but good as hunlee hear of them befor!!!!If Hunlee not allready have nice 7-30 water barrel maybee 30-30ai wood be very good for Hunlee!!!!!

hunlee

i've formed most of my AI cases at max 30-30 loads. they are very accurate, with no "failures" and there is no reason you couldn't hunt with them as well. factory loads are usually near max.
overall brass life....i can't say. i have hundreds i picked up reasonable or from the few boxes of factory loads fired. in rotation for hunting, they will last a long long time.

Thanks for the help Gary. I should have stated the minimal powder charge listed in a reloading manual.

As for the brass life during fire forming, I think it was because I was using 30-30 brass for the 7-30 Waters and tested a few at the “maxim charge indicated in a reloading manual” with a 139 spbt.(It was a wildcat and not a improvement.)

kyode got it right, I wasn't plan enough I was once you already had them fire formed how loong they would last. It seems as though it isn't any different then reloading any brass. I thought that maybe the shoulder area would become thinner and more prone splitting. Thanks guys.

The entire idea of an AI chamber allows one to fire a factory round in it to form the brass to the AI. Ackley kept the head space the same as the factory chamber. One can use a reduced load to fireform brass but it is not necessary.

AS for case life, this is more a function of how tight the chamber is. If the chamber is a min SAAMI spec'd, (body and neck dia.), the brass will last a lot longer. The reason cartridges do not last is mainly due to large chambers and bigger than needed neck diameters. The firing and resizing of brass causes it to work harden, which leads to brass becoming britle and splitting.

A lot of people really do not realize that with a min spec'd or tight chamber and neck that brass can last more than the 2-5 firings. I have competitive benchrest rifles chambered in 6mm PPC and a tight necked 308 obermeyer (0.333") that cases will remain competitive well over 30 firings. I have 6 ppc cases that have lasted over 50 firing/case! However, one also has to make sure that the headspace of the case is just slighlty bumped to allow easy chambering. If you oversize a case, the case will lengthen and cause the case to get thin at the web (0.200") up from the rim of the case.

Lastly, the AI case will also help keep the case from lengthing compared to the parent case that has more body taper.

Mike

Welcome aboard there MSwickard.

Good stuff

Thanks rupe

Mike

Oh yeah the case at the shoulder gets thinner. But in most cases you really dont move it that much . My 218 bee ack jumps almost .25 of an inch and I have about 30% case loss on average. My 30-30 ack even using hot loads has almost no case loss. It all depends on the initial brass you use . They say you shouldn't use anything but new brass , but on my 30-30 ack it doesnt seem to care . It will run anything, and form perfect everytime.Just some food for thought.

Lars