Home Forums Hunting & Shooting Hunting Rifles Ackley Improved Question

I was doing a Google search about Ackley Improved. Was looking up 243 to 243 AI. Come across a few things people had wrote from various forums saying there are no real advantage to doing this. So thought I would get some opinions and if anyone has had one reamed for AI. Never had one done but if one had a 243 in a tikka t3 what are the steps for a gunsmith to go AI.

Remove the barrel, set the barrel back a full turn, I don't know the thread specs of a Tikka, but it is usually around 1/16", cut a new chamber, and set the headspace.

I have read, IIRC, that the sharper shoulder of the 243AI reduces the speed and amount of throat erosion that is common to the 243.

Yes, in my previous .243 AI rifle it reduced throat erosion by about 10%, judging from measurements taken when it was a .243 and then after it had been set back and chambered to .243 AI. Nothing to write home about but still, it is an improvement.

You only get about a 5% case capacity increase, my cases averaged around 4 point something % increase. The 1 in 4 rule gives an estimated 1.5% increase in velocity at same pressure, so assuming 3000 fps for 100 grain bullets you get a whopping 45 fps increase! Changing the shoulder angle also seems to calm down the .243's bad habit of wider pressure swings in a given string. The .243 had been loaded down a bit after that was discovered in order to keep the highest pressure reading in a string below the max allowable.

I've used those two concepts together to justify going another 50-75 fps over max .243 loads and going by primer pocket life pressures are still very safe. My cases have been fired 22 times and I'm just now seeing some stretching of primer pockets evidenced by easier seating.

Like most all Ackley improved cases, it also greatly reduces or eliminates the need for trimming. Those 22x cases still aren't even close to max length yet from having been trimmed back on their second firing.

Overall, I like it. It doesn't give a huge velocity advantage but you can go a little higher with safety and mostly you get the other advantages of the improved case.

How much does it cost have a gunsmith do that work?

The whole Ackley improved thing is overblown, and if you want
bigger performance, go with a larger caliber.

All you will do is spend lots more money for not much gain.

Depends on the cartridge. If you have a cartridge with a fairly sharp shoulder already, you won't see much gain obviously, because there is very little case capacity improvement available.
However, in the right cartridge it can do wonders. I have a 300 H&H AI that is head and shoulders in performance over the parent cartridge. It's been years since I chrono'd it, but the loading specs for the H&H improved are 300 Weatherby. Same capacity and length, powder charge and performance.

My .223 AI also outperforms the parent cartridge very well. Very close to my 22-250 in performance without the heavy recoil. In both of these rifles, I can shoot the original parent cartridges and the accuracy is phenomenal. Just one more advantage of the AI upgrade.

Bob

Some people say there's no advantage to an AI. They're wrong, they just don't know. There's varying degrees of improvement in velocity depending on which chambering, but it's always there. With the .243AI......a .243 case has a shallow shoulder angle but little body taper, so it doesn't blow out so much as others do. But making it AI moves the performance up a definite step.......70gr bullets will be going as fast or faster than 60's through a std. 243. That's a noticeable gain. In mine, accuracy load with 70's is 3800 to 3860.....depending on which gun/bullet/primer/etc. I don't know if the sharper shoulder means less throat wear. But where many std. cartridges shoot best with less than max load, Ackleys are accurate at or near top end......the extra usable velocity isn't just from more powder. Only you can judge if it's worth doing or not.

100 FPS (2,900 to 3,000) gain with a .500 BC is 3.8" less drop and 0.9" less drift at 500 yards. If that makes a difference for you.

I think unless you're a fearless experimenter, AI cartridges should be avoided because there's usually very little pressure tested published load data available.

I've recently got into my first ever AI, a 250 Savage AI. All you really have is 250 Savage and 257 Roberts data, with the 250 AI sitting about smack in the middle for case capacity. You have Quickload, a little bit of stuff published in the odd magazine article, and the internet experts from which to derive your data.

Add the fact that most 250 Savage and 257 Bob data is maxed out around 45000psi, and working up to loads in the modern rifle 60000psi bracket is a journey into the unknown.

Not suggested for the overly-cautious type.

Perfect example of a dope who posts without knowing what the h#ll he's talking about.

Thanks Ackman. You are a gentleman no doubt.

By the way you did well to determine that I'm a dope from there.

Agreed, AI's aren't good choices for idiots.

Iv'e never felt the need to drive a bullet just as fast as I can push it as I figure accuracy first and most of my rifles seem to be more accurate a little before max. Most of the places I shoot 450 yards is about the max and I have to drive better than an hour to be able to shoot that far. I have, however, considered doing AI in my .223 and .243 for the fact that there is less brass trimming. I'll probably just wait till they need rebarrled. My favorite .243's is getting close I believe.

Dave.

The amount of time saved trimming brass is funnier than schit.

Touchy subject I guess I'm just trying to learn about AI

Jim in Idaho;
Top of the morning and indeed Happy Fourth of July to you sir and kudos for a concise and in my experience very much correct answer.

We've currently got two AI chambered rifles in the safe - a .22-250AI and a .250AI and I've played a bit with an '06AI in the past.

If I could find a local smith that would do the job for a reasonable price, I'd convert our .223 to an AI chamber in a heartbeat.

I'll not rehash your answers, but again found that when using the 1:4 rule, measuring the resulting case capacity and using a chronograph it's no trick to arrive at safe handloads with an AI.

Honestly as I was typing this I can't recall a single time in more than two decades that I've ever trimmed a case for the .22-250AI..... they just don't lengthen. Added - we've only had the .250AI for a decade and didn't shoot it as much, but didn't trim those cases either.

Locally I'd say that having an AI chambered rifle might knock the value down a tad to the "average" buyer, but that's a guess on my part.

As I don't typically buy rifles I want to experiment with and take resale into consideration I'm not sure. By the time I'm done fooling with the bedding, crown, trigger - maybe making a new stock - well again you get the idea sir.

Anyway sir, thanks for the comprehensive answer and all the best to you and all my friends south of the medicine line this Fourth of July.

Dwayne

Everyone has things they value more than others. The effects on trimming brass is the big one for me. A little gain in velocity is nice, but for my uses really not that important. Not having to trim brass makes me smile.

After this spring's varmint season Im sitting here looking at 1600 rounds of .223 brass that now needs trimmed.


Wish I'd taken the .223AI

They ain't called 'Improved' because they do less.

Three paragraphs in your post, all nonsense. And one sentence, also nonsense.