.243 Ackley Improved

Yes, but it is only beneficial to some. The 243 and 280 are by far the most popular, and that is because you see the biggest gain with them. The 280AI is almost a 7mm Rem Mag but without the rimmed brass and recoil. With the 243 you are pushing bullets faster then the 25-06 but in a short action rifle with less recoil.

Some people like them, some dont.

Tim
 
I would say yes for any chamber could be “Ackleyized” however, at a price and provided it’s safe to do. You will find most popular commercial cartridges have the 40 degree shoulder Ackley version available both reamer and dies. If you want to do something oddball, you will have to invest $$$ for reamer, dies, and smith to do the work. Then there is time and more $$$ spent to develop the cartridge. Wildcats don’t come cheep but provide me lots of enjoyment. I have a 257 AI, 7x57 AI plus 3 JDJ wildcats. And the wheels are turning as what will be next.

B..
 
My daughter shoots a 22-250AI and my son shoots a 223 AI, I shoot a standard 243, but when I change the barrel it will definitely be a 243AI. They are both very accurate rifles. and the cases look cool too! /ubbthreads/images/graemlins/grinning-smiley-003.gif
 
So for a .223 and .243 rechambered for AI what is a good twist ratio?

What is a good price to have a rechambering done to AI?
 
For twist ratio's it depends on what bullets you plan on shooting out of it.

As for a price, that depends on quite few things.Where you are, quality gunsmiths in your area,etc. And in my personal opinion, I wouldnt re-chamber a used gun to AI, I would either buy a re-chambered barrel or re-chamber a new barrel. This way you can decide what twist rate you want and barrel length,contour,etc.
 
Because it is more then likely not going to have the twist rate you want for a AI Cartridge.Most factory rifles come with high or fast twist rates to shoot the popular weight bullets for that caliber. With an AI you have the power to shoot the heavier weight bullets but wouldnt have the correct twist to stablilze them in flight.

Make sense?
 
Quote:
Because it is more then likely not going to have the twist rate you want for a AI Cartridge.Most factory rifles come with high or fast twist rates to shoot the popular weight bullets for that caliber. With an AI you have the power to shoot the heavier weight bullets but wouldnt have the correct twist to stablilze them in flight.

Make sense?



I have a Savage in .243 Win. I had the action trued by Fred Moreo of Sharp Shooter Supply when I bought the gun. I was considering getting it rechambered at that time to the AI version, but decided against it for the reason that I intended to shoot the 70 grain Nosler BT and felt I probably wouldn't gain much by being able to push it faster in the factory twist.

As it turned out, it was a good decision, since while I can drive the 70 grain bullet up to about 3600 fps. with certain powders, my best accuracy/velocity with that bullet is between 3400 and 3450 fps. Faster than 3450 and the accuracy drops off considerably. With the AI chambering, all I would have been able to do was use more powder to achieve the same 3000 to 3450 fps. that shot the best with that bullet.

I chose the 70 grain bullet over the heavier bullet because we have very flat ground and ricochets are a potential problem with heavier bullets.

When I shoot this barrel out, I will get a 1 in 12 twist and may then go with the AI version.
 
Quote:
ackley improved, is a chamber cut as to remove most of the body taper and changing the shoulder angle to 35 or 40 degrees. RR



Actually, only the 40 degree shoulder is an Ackley - the 35 degree shoulder is a Mashburn Improved. Mashburn and Ackley were competitors for the same market.

Mashburn's work was better, but Ackley was a better salesman.

Quote:
Because the Ackley Improved chamber is longer than the standard 243 chamber.



Look at the pictures - the Ackley chamber is shorter. That is why the barrel must be set back a full turn to make an Ackley chamber. Note the the neck on the Ackley case is longer than the original.

223AIcase.jpg


You can re-chamber most factory chambers for an improved version, but the cost of custom dies may make it an unwise decision.

Advantages are longer case life, and a bit more velocity (and a bit less barrel life).

If you are making up a rifle that will use 50 or 100 cases, you can fire form the cases in one afternoon at the range. But if you have a rifle that you need 1,000 cases for, then fire forming is a real nightmare, and may not be worth it.

I am in the finishing stages of a new 6mm Rem (.244) chuck rifle, and considered the AI version, but I have 1,050 cases for it, and I have no interest in fireforming 1,050 cases... it would eat up nearly 1/2 of the barrel life just to make the cases, so I chose the standard version.


.
 
Quote:
Look at the pictures - the Ackley chamber is shorter. That is why the barrel must be set back a full turn to make an Ackley chamber. Note the the neck on the Ackley case is longer than the original.



Cat is this "etched in stone" or just preferences by certain smiths?

Reason I ask is I've got quotes on AI rechamber jobs in the neighborhood of 60-75 bucks and seems thats alot of work for that much money if every barrel must be set back.
RR
 
Most Ackley chambers are headspaced .004" shorter than a standard caliber and you get a crush fit on a factory case when you close the bolt at least that is how my Ackley chambered rifles are set up. For my 222AI etc I found a good varmit load and fire form case with those loads larger cases like 6RemAI I fire form using bulleye and COW without a bullet.

Here is a quote from P.O. Ackley published in Speers Wildcat manual #4 1959. "P.O. Ackley, however, says he does not care what presures are just so long as he does not have extraction trouble or primer leaks, and he says that the straight body facititates extraction and prevents undue backthrust on the bolt."

I started with a 45gr/IMR-4350 and 80gr bullet which is a max load in Nosler # 6 load density is 92%. To the base of the neck on a 243 Win case it will hold appr 49gr IMR-4350 and that is more powder than I load in my 243AI to get 3700fps with a 80gr bullet so I might be at the same load density as the 243 case.
 
I had a list of what cartridges benefit the most from AI-ing them, but can't find it. Some are hardly worth the trouble, unless you just hate trimming brass.

I almost went with a 243 AI, but built a 6mm-06 instead.

I might AI my 35 Whelen......
 
I have the 243AI and love it!!!! The AI version of this round yeilds about an 8% increase in case capacity over the parent round. THere is an article in one of the old Precision Shooting Mags with a chart listing the most efficient versions....
I have a 10 twist with a 28.5 " Shilen tube shooting the 70 grain bliztkings at ~3850 fps..this rig is a laserbeam and a joy to shoot. Accuracy is good to, as I'm getting .75" groups at 325 yards. I've made shots out to 890 yards with this rig, so I'm very pleased with it's performance... when this barrel is burned out, I would definitely do another one. Sam
 
Quote:
Quote:
Look at the pictures - the Ackley chamber is shorter. That is why the barrel must be set back a full turn to make an Ackley chamber. Note the the neck on the Ackley case is longer than the original.



Cat is this "etched in stone" or just preferences by certain smiths?

Reason I ask is I've got quotes on AI rechamber jobs in the neighborhood of 60-75 bucks and seems thats alot of work for that much money if every barrel must be set back.
RR



Ridge...

If a 'smith does this on a regular basis and has his own reamers, it is not a lot of work.
He'll have the gauges and tools so it goes fast. Maybe an hour or a little more.

If the 'smith does not do this often and has to rent the reamers, then the setup and figuring the cuts are very time consuming, and that's where the loss is.

There are 'smiths that do not set back the barrel - they just cut the new chamber into the old one, and there is no crush fit.
Forming cases must be with a bullet fully seated into the lands, and the case oiled for full setback and forming. It is an OK way to do it, but case forming takes more knowledge to avoid headspace problems, and it is not for the beginner.

The true "Set-back Ackley" is idjut proof /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/wink.gif


.
 
I was asking about this topic in the predator forum and it likely should have been attached to this thread. I originally asked about .243 AI for predator hunting, but the thread drifted to the fact I may be wasting my money for rechambering a .243 factory barrel that has average accuracy and has had 500+ rounds fired.

If my gunsmith has the reamers, will set back the barrel and rechamber to an AI, and true the bolt for $275., is it a bad investment? I plan to shoot lighter bullets for coyotes and 85 gr. TSX for deer.
 
As I stated in your other post... I'd spend just a few more bucks, build a barrel with a faster twist such as a 1 in 8. You will have the benefit of being able to shoot the heavier bullets and still the light bullets.

Mine is a 1 in 8 twist and I shoot the 115 DTACS at 3178. Great high BC of .585, excellent in the wind, and longer distances.

I feel it would benefit you greater to spend another 100 and you'd have an incredible shooter capable of more bullet weights and accuracy.

Here are my specs....


243AI Rifle Specifications:

Winchester Short Action Push Feed (Originally M70 heavy varmint in 22-250)
Broughten Medium Palma Barrel 1/8 twist 5 L/G 30 inches long
Action blueprinted, magazine box modified for proper feeding, 4+1 rounds.
HS Precision Winchester varmint stock, skim bedded with marine tex
Chambered with PTG 243AI reamer built specifically for the TUBBS 115 grain bullets. Tight chamber, tight not turn neck.
Jewell HVR trigger set at 28 ozs.
Nightforce 3.5-15x56 2DD reticle
Nightforce 20moa 1 pc base.



Load:
Winchester Brass 243 win.
Federal 210m primers
115 grain DTAC Moly .585 BC
2.815 OAL .010 off of the lands.
48.5 gr. RL25 (46 gr. RL25 fireforming load .5moa or better, good velocity)
3178 fps

Rifle in action... 423 yard Antelope this year...
346012007_Goat_423_yards.JPG
 
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