Home Forums Hunting & Shooting Hunting Rifles Ackley Improved Question

I have a sako a7 that I had rechambered to 243 ai. As others have mentioned, I enjoy not having to trim brass and I can shoot the same speed as the normal 243 at less pressure which makes by 243 ai brass last even longer. The cost of the rechamber job will pay for itself in savings because my AI brass lasts longer and I have some extra horsepower for 80gr ttsx for hunting. If I had any other cartridge worth AIing I would do so again in a heartbeat.

That’s why these are made:

The 243 AI will perform about like a 243 with 2” more barrel length. I.E. you will never, ever see the difference in the field.

So the guys that do not like the AI do you guys just not like wildcat rounds or just old fashion

I’ve owned a dozen or so rifles chambered for various Ackley Improved cartridges, as well as designing and building a Wildcat cartridge. They were fun, but none did anything a standard round wouldn’t do just as well. If I were to do it all over again, I might still go through the process just to learn....but the extra money for dies and chambering would have been much better spent on components for current rifles. Or hunts.

If looking to chamber a new barrel, an AI round makes a little more sense, as the chambering costs should be the same. But rechambering a barrel that shoots fine is a waste of money. Also, one is highly unlikely to see the money of chambering and dies recouped in brass savings (especially in a relative barrel burner like a 243 AI), unless the original chambering was loaded really hot and the AI not so much, or the original chamber was really sloppy and brass was overworked during resizing.

In my experience, the Ackley Improved rounds have been weighed, they have been measured, and they have been found wanting.

Most of the velocity gain in AI rounds over the parent round is due to handloaders working up loads to the point where they start to see "pressure signs," then backing off a little. This normally results in somewhere between 65,000 and 70,000 PSI in most brass.

I ran an experiment a couple years ago, loading up the the standard .223 with TAC and 40-grain Ballistics Tips, increasing loads by half a grain of powder until pressure signs appeared. This resulted in 3950-4050 fps, depending on barrel length (my wife and I have several bolt-action .223's with various barrel lengths from 22-26"), vvery close to what .223 AI users report. This is because the standard SAAMI pressure for the .223 is only 55,000 PSI, so working loads up by "pressure signs" is adding at least 10,000 PSI. Naturally this results in considerable more velocity.

Some cartridges gain more by the AI process than others, obviously, both because of the standard round's SAAMI pressure limitations, plus case shape. But in most modern rounds with little body taper and fairly sharp shoulders the gain in powder room isn't more than 10% and often closer to 5%. (In the .35 Whelen AI, the most useless AI round ever developed, it's more like 3%.) This means an increase of around 1% to 2.5% increase in velocity when loaded to the same pressure as the parent round, but most AI rounds are loaded to higher pressure, because very few commercial cartridges have a SAAMI maximum pressure of 65,000 PSI.

The lack of case-stretching in AI's is sometimes a handy feature, but many modern commercial rounds have shoulder angles of around 30 degrees, pretty close to the AI 40 degrees, and don't stretch much either. The .223 AI does stretch a lot less than the standard .223 with it's 23-degree shoulder, and the same is true of the .243 AI and .257 Roberts AI. But the .204 Ruger already has a 30-degree shoulder so doesn't stretch much anyway.

Diminishing returns and keeping schit simple.

I like the AI due to lack of trimming. I hate the AI due to having to have a fireform charge and a formed charge.

Oh did I say gentleman?

I meant poofter.

The "question" regarding AI chambers comes up about once a month, answers are generally the same. If it floats your boat, roll with it. A fella can be pretty satisfied when he does what he wants.

Probably have about a half dozen posts left before the whole thread turns to schit. Sounds like we're almost there...

I always avoided AI and wildcats of every type as much of my rifle uses were in remote parts of BC and I could not have loading gear with me, so, factory ammo was it. That was limited in supply and was usually only available in a few very common cartridges.

I am retired, new 4x4 and lots of fine bolt hunting-wilderness working rifles, sooooo, I decided to try a Kimber 84L MA-.280AI....and I am liking it very mucho so far.

A "looneys" round and I called Accurate Arms for loading data/advice, but, it DOES beat any of the several .280Rems I have had since 1985 and it certainly shoots.

So, whatever blows your skirt up, its all fun, eh!

Keep in mind that a properly executed AI will shoot the parent cartridge just fine. And as I've read in several reloading manuals and proved in my AI cartridges, the accuracy with the parent cartridges can be pretty amazing. No need to be concerned about having to load ammo in the field unless you can't find the parent cartridge in the area you are shooting/hunting. What's not to like?

Bob

Expound on this concept please.

I think Ive been missing something....

Ingwe,

Here is a link. http://www.littlecrowgunworks.com/wft.html


I just purchased one of these Frankford Arsenal trimmers and it works great. http://www.midwayusa.com/product/628405/frankford-arsenal-platinum-series-case-prep-and-trim-center

Thanks!!!

Welcome to the 21st century Ingwe.

I found this pic of a trimmer made specifically for AI cases:
















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My favorite part is how guys will spend hours tinkering with the most minute reloading process, then bitch about trimming, which might take a few hours a year, if a guy shoots a lot.

If some of these guys spent one tenth the time trimming cases as they spent bitching about trimming cases on 24hourcampfire, the job would be done. But then they would have to find something else to complain about.

But hey, this is America. Spend your money as you wish. Buy a one ton pickup to haul a gallon of milk. Spend money on useless cartridge conversions and justify it by saying it will save a minute amount of time in case trimming, so you can feel like you accomplished something. It's your money to piss away as you see fit.

Why does this subject make you so angry?