Ackley Improved Education

Hello all!

I started this thread about the .22-250 which quickly went to…get that chamber improved!
https://www.longrangehunting.com/threads/custom-22-250.355626/#post-3066278

The above thread interested me in the AI treatment of a cartridge greatly. So I'm doing research. The vid below was insightful.


What is your experience with the AI world? What is your opinion why more cartridges aren't SAMMI approved?

What cartridges have you tried and didn't think the juice was worth the squeeze?

Fire forming tricks/shortcuts?

Dies…how hard to obtain what you need? Redding seems to make many. Other ideas?

Gun smith pluses or minuses with your experience?

Can you do prefits? If so, who?

Is the case life extension a legit?

I'm a very traditional guy when it comes to cartridges. I enjoy getting what I can out of factory rifles. I've been loading for 30 years and I feel it's time to get weird. Thanks in advance!

AI everything is what I say, not trimming brass is one of the greatest benefits

The 22.250 ackley improved pretty well equals the 220 swift loads. In Ackley's own words he saw more improvement with the 250 savage after improving. Than any other cartridge. There was quite an increase in powder capacity because of the taper of the cartridge. The 250 savage being the parent cartridge of the 22.250. I have a 280ai and it does show some improvement with heavier bullets, over a 280. Good luck on your project. If the chambering is done right( setting the barrel back one thread). Then you can fire your regular ammo in your chamber and voila the improved case pops out.

I have a 22-250 AI and a 6.5 Sherman (basically 6.5-06 AI but with more shoulder movement). The 22-250 is a great cartridge to AI for various reasons, already stated in the previous thread.

If your barrel is chambered correctly, factory ammo should have a slight "crush fit" when chambering a round. This will ensure correct headspace.

ButterBean said:

AI everything is what I say, not trimming brass is one of the greatest benefits

Click to expand...

What calibers have you done @ButterBean?

My question about doing AI to a CASE is if it was such a great benefit why does not the Ammo, Die, REAMER, Rifle manufactures all make cartridges in AI???
And yes we do have AI cartridge

Coyote Shadow Tracker said:

My question about doing AI to a CASE is if it was such a great benefit why does not the Ammo, Die, REAMER, Rifle manufactures all make cartridges in AI???
And yes we do have AI cartridge

Click to expand...

Feeding issues with ai's they claim which for manufacture stand point i get

Coyote Shadow Tracker said:

My question about doing AI to a CASE is if it was such a great benefit why does not the Ammo, Die, REAMER, Rifle manufactures all make cartridges in AI???
And yes we do have AI cartridge

Click to expand...

Valid question!

There are now many examples of cases being 'improved', just not having the name attached, other than the 280AI.
I have many 'improved' cases, not all are Ackley mimics, some are my own criteria running absolute minimum case taper of .005" per inch.
I don't form my cases using bullets 99% of the time, I use COW and toilet paper, it is cheap and does not diminish barrel life if the barrel is allowed to cool often enough.
The advantages are many, such as, my 375 Weatherby has not needed trimming since the cases were formed, most have been loaded and fired 5 times, some are more. An additional 200fps+ over the 375H&H is substantial, it changes the outcome immensely, etc, etc.

Cheers.

Coyote Shadow Tracker said:

My question about doing AI to a CASE is if it was such a great benefit why does not the Ammo, Die, REAMER, Rifle manufactures all make cartridges in AI???
And yes we do have AI cartridge

Click to expand...

I could be wrong, as always, but I would suspect it's because there isn't an AI SAAMI spec.
Like it said in the video, there are a lot of incorrectly done AI chambers and the manufacturers won't touch that.

MtPockets said:

I could be wrong, as always, but I would suspect it's because there isn't an AI SAAMI spec.
Like it said in the video, there are a lot of incorrectly done AI chambers and the manufacturers won't touch that.

Click to expand...

Anytime a case has been designed with much less case taper, forgetting what shoulder angle is used, is simply an Ackley concept adopted and used, SAAMI accepts that and implements those dimensions. Winchester were fundamental in reducing case taper on many of their 1950's case designs. I'm sure these were inspired by P. O. Ackley's designs.

Cheers.

243AI, 250AI, 257AI, 280AI, 7x57AI, and a 244 RemAI in the works. Love em. I use manson hs gauges since they have the .004 crush fit built into them

Coyote Shadow Tracker said:

My question about doing AI to a CASE is if it was such a great benefit why does not the Ammo, Die, REAMER, Rifle manufactures all make cartridges in AI???

Click to expand...

Its incredibly expensive and risky marketing to develop a new round but several new calibers that have become popular these days have very similar attributes to the Ackley Improvements.

I think most factory cartridges don't follow Ackley's case dimension standards (40* shoulder and 0.10/in case taper) because of the potential for feeding issues but likely the weight is more towards the case taper hiding pressure signs and having potential for extraction issues.

I think the biggest benefit is likely usually reduced trimming, but can significantly increase powder capacity depending on the cartridge. 260 rem and 6.5 Sweden both have significant gains in powder capacity. 308 win ai, not so much.

A benefit of minimal case capacity increase could be for being able to hit a certain powder charge weight and bullet combo that shoots particularly well. Alex Wheeler's work is a good example of improving cartridges. He does iterations on chambers to find what works best for a particular bullet. BUT, that is for a single use scenario. If you're looking for general speed and accuracy, that may not fit your specific use case.

For gunsmithing, doing AI work is not as simple as running the AI reamer in.... To do it properly the barrel needs to be set back so that a 0.004 headspace crush fit is obtained when loading the factory case. Which brings another benefit; being able to shoot factory ammo in the AI chamber.

I did a 30-284ai, mostly for slight powder capacity increase and reduced trimming. The jury is out on if it would be better than a straight 30-284 because my first chamber cut with the reamer was sloppy. That's my one experience with an AI chamber aside from researching it heavily.