Educate me - original cartridge vs. Ackley Improved?

[Ku-winda]

I'm not sure the specifics of my question have been covered before (I couldn't find it), but if so, apologies in advance. I know the original cartridge can be shot out of the Ackley Improved version rifle, which is in fact how most of the brass is formed (provided there are no factory offerings like .280 AI, etc.). My question is this - after the original rifle has been converted to AI, can you ever achieve superb accuracy with that original cartridge? Pick your round, but say 257 Roberts out of the converted 257AI rifle. Obviously the reason most of these were converted in the first place was to achieve better performance, so this isn't about the merits of one cartridge over the other, but rather will that rifle shoot both equally well or will the AI round now be inherently more accurate. Any insight would be appreciated.

 

[albravo]

280ai is one of my favourite cartridges. I've never thought of shooting a .280 Rem in one and am curious to see what the brain trust on AH says.

 

[D.M.V]

Interesting topic. So I've read elsewhere that you can shoot the standard caliber in the AI and shooters do this in the beginning for firefoming the brass. But please do your own research. This is my own opinion based off of something I've read on the Internet. I do not own a AI converted rifle so do not take my word for reloading advice for your particular rifle. I will add. I shoot 220 Russian brass that has been necked up and necked turned to shoot my bench rest 6mm ppc so I'm familiar with firefoming and creating case's that are not available commercially

 

[Ku-winda]

280ai is one of my favourite cartridges. I've never thought of shooting a .280 Rem in one and am curious to see what the brain trust on AH says.

I am as well, thanks!

 

[JimP]

As for accuracy with the Ackly I'm not sure.

However I fire form 7-30 Waters brass from 30-30 brass which blows out the shoulder of the 30-30 brass similar to what the Ackly Improved does with its cases and have found that the case forming rounds are just as accurate as a fully formed 7-30 round is, as long as the same load combination is used.

 

[Mekaniks]

I had a 30-06 AI. I form fired all the brass and accuracy was not an issue for me. It did shoot to slightly different points impact which I attributed to the difference in velocity. But regardless, I sited it in with the AI loads and always hunted with the AI loads....

 

[Ku-winda]

I had a 30-06 AI. I form fired all the brass and accuracy was not an issue for me. It did shoot to slightly different points impact which I attributed to the difference in velocity. But regardless, I sited it in with the AI loads and always hunted with the AI loads....

Thanks @Mekaniks - even though they had different points of impact, was there any significant difference in accuracy between the two?

 

[Boone66]

If the barrel shot the parent cartridge good, it will shoot the AI cartridge good and the parent case good also, as noted above, you.will have a loss of velocity, mostly because the case volume is increased. If bullet, brass etc are the same, it should shoot well or relatively well. I own and have owned several AI rifles over the years. I shot prairie dogs fire forming 22-250ai. Did pretty well, not as.good as the hand loads, but bullets and the AI OAL was different on my finished cartridges. But, good enough for PD's out to 600yds. What exactly are you trying to accomplish? If it's a case of you forgot your ammo on a hunting trip, expect the factory stuff to not shoot as good as the AI hand loads, but that is true with all hand loads vs factory ammo. My dad and grandpa all shot AI rifles and never had a problem hitting anything with factory ammo, it will shoot different like any other change in bullet, brass or primer, but it will shoot, just probably not sub MOA. The best thing is to is after you figure out what bullet your rifle likes, try different factory loads, and pick the top three and write them down, so you will have the information when you need it and your far from home.

 

[Ku-winda]

If the barrel shot the parent cartridge good, it will shoot the AI cartridge good and the parent case good also, as noted above, you.will have a loss of velocity, mostly because the case volume is increased. If bullet, brass etc are the same, it should shoot well or relatively well. I own and have owned several AI rifles over the years. I shot prairie dogs fire forming 22-250ai. Did pretty well, not as.good as the hand loads, but bullets and the AI OAL was different on my finished cartridges. But, good enough for PD's out to 600yds. What exactly are you trying to accomplish? If it's a case of you forgot your ammo on a hunting trip, expect the factory stuff to not shoot as good as the AI hand loads, but that is true with all hand loads vs factory ammo. My dad and grandpa all shot AI rifles and never had a problem hitting anything with factory ammo, it will shoot different like any other change in bullet, brass or primer, but it will shoot, just probably not sub MOA. The best thing is to is after you figure out what bullet your rifle likes, try different factory loads, and pick the top three and write them down, so you will have the information when you need it and your far from home.

Good intel, thanks. Was really not trying to accomplish anything per se, but posing the question in the event one didn't have access to the AI rounds (for whatever reason) and had to go back to the parent cartridge, what would that to do to your accuracy? It sounds to me based on your experience that it should shoot about the same as it did originally - no better, but no worse. Am I interpreting that correctly? Thanks.

 

[Boone66]

Good intel, thanks. Was really not trying to accomplish anything per se, but posing the question in the event one didn't have access to the AI rounds (for whatever reason) and had to go back to the parent cartridge, what would that to do to your accuracy? It sounds to me based on your experience that it should shoot about the same as it did originally - no better, but no worse. Am I interpreting that correctly? Thanks.

That has been my experience, to truly get everything out of it, you should hand load for it.

 

[Mekaniks]

Thanks @Mekaniks - even though they had different points of impact, was there any significant difference in accuracy between the two?

No, I never noticed and accuracy difference between the two.

The only issue I had was case life. I would only get 2-3 reloads out of the brass after it had been fire formed. They would crack at the shoulder....It was probably old Remington brass, but I don't remember for sure.

 

[Ku-winda]

Conceivably then, a good handloader should be able to make either the parent or the improved cartridge equally accurate (or at least fairly close) out of the same rifle, knowing of course there is going to be a substantial difference in velocities given case capacity.

 

[JimP]

No, I never noticed and accuracy difference between the two.

The only issue I had was case life. I would only get 2-3 reloads out of the brass after it had been fire formed. They would crack at the shoulder....It was probably old Remington brass, but I don't remember for sure.

This is where proper annealing would help for case life.

 

[Mekaniks]

This is where proper annealing would help for case life.

Yes sir for sure would have helped.

 

[Boone66]

No, I never noticed and accuracy difference between the two.

The only issue I had was case life. I would only get 2-3 reloads out of the brass after it had been fire formed. They would crack at the shoulder....It was probably old Remington brass, but I don't remember for sure.

Did you anneal the cases

 

[CBH Australia]

I've heard of people getting good groups while fire forming the brass and if you shoot a factory load in the a.i. that is effectively what you are doing.
I don't expect using factory ammo in an a.i. chamber to aid accuracy but I don't think it there is any reason for it to be inherintly bad either.
If the bore and crown are good with a good load then it has the potential to be accurate. As others said if it's not the best load for the rifle it won't be the best result, but it may still we'll be accurate.
If you tried various factory loads in a certain rifle some will be more accurate than others. If you convert that same rifle to an Ackley improved chamber you might find a different result with the same factory loads. Different chamberings and different rifles might well be a different result again.
That's my take and I haven't read anywhere that an Ackley Improved chamber will increase or decrease accuracy over a standard chambering.
I read a lot on the subject when I decided to have a .280a.i built. One thing that does come up is that some chamberings get more velocity advantage than others. The .280a.i. being one of them. Apparently some get proportionally more gain and that's why they have become popular. You can a.i. a .308 but apparently the gain is not getting the same % increase as some others so it's rarely done.

 

[Luvthunt]

I had several 223 AIs where I fire formed all my own cases. Shot PDs every year for many years. Had 1500 cases for each 223 AI and ea year had to fire form new cases to maintain the 1500 level.I found accuracy as to group size to be similar but poi different enough to miss a dog at 250/300 yds. Always zeroed in to begin with fireforming then rezeroed thr AI ammo.
But group size was not significantly different. Just for added info used Win 748 early then switched to H335 and never changed.

 

[Stompbox]

I had a Cooper firearms .25–06 AI. When I was shooting my fire form loads, they shot so good that I hunted with them for a couple of years until I had a good supply of formed brass. I recently built a 6.5–06 AI, and that one also shoots the fire form loads very well, but those I don’t hunt with because I wanted the extra performance of the Ackley improved cartridge right away.

 

[mauserhunter]

There are many pros of having a Ackley, there could be a few negatives but that's with anything when comparing. If a AI chamber is set up right it should have about .004" of a inch crush fit normally where the neck meets the shoulder. This is why is safe to shoot the original cases in AI gun there no heads pace. You can't just ream say a 280rem gun to 280ai, you won't have that .004 tolerance and excessive headspace. Barrel needs to be cut back a tread and chambered with the AI reamer. The go gauge for your original round now becomes your no-go gauge and you need a Ackley improved go gauge.

Most often the original rounds will shoot very well in the AI chamber, you will have some resistance when closing the bolt when shooting the original case in the ai chamber this is normal and how all ai guns should be. After fireforimg the resistance closing the bolt isn't there.

To save money and a bullet to fire fore you can use the cow method, using fast pistol powder like red or blue dot you load a few grains in the case, you will have to test and see what charge of powder fully forms the case. On top of that you fill the case to the neck with cream of wheat, you can add a square of toilet paper on top to hold everything in if you can't fire into the air but down level. Don't do this if you have a muzzle break or anything other muzzle device.

Some of the benefits of the Ackley are, more powder space for more powder to fit in the case even if loaded to the same psi you will gain speed, better brass life, less thorat erosion leading to longer barrel life, better case seal, less bolt thrust. There are more I just can't remember my brain is half asleep. Often with Ackley rounds you won't see much pressure in the case until your pretty high into pressure, so your normal way of reading the fired cases and primer gets a bit harder. The less bolt thrust doesn't flatten primers as much. Often you original rounds near max load is now your starting load for you Ackley, I like to be a few grains from max to be safe and you may get another accuracy node.

Some bad other then it being harder to read pressure is feeding in the action some guns won't feed the improved case well and you magazine stack will be different to. So your magazine may need so work or the rails on your gun. Was just shooting my 1909 argentine mauser today in 7x57Ai and it will feed empty round from the mag, will even do it with 280ai as well so feeding can be really good with a Ackley. Reloading dies can be pricey and hard to get, many seater dies won't work with the Ackley if your looking to use the patent cases dies, lee seaters seem to have enough room to use there's tho. Resale is probably the other bad, tho the people in the know may pay more for a Ackley but gun shops and the average shooter won't.

 

[AZDAVE]

@mauserhunter Gave a solid description of setting up the barrel for AI rounds. I have shot several AI variants over the years and the biggest benefit I have seen is that the need to trim cases as often goes down and case life improved. I was getting 6-7 reloads out of remington 06 brass and 9-11 reloads from AI brass as long as they weren't loaded to hot.

The biggest thing I have observed is that some folks have tried to turn say a 30/06AI into a 300WM. ALWAYS keep the rounds you are loading normal or AI within it's performance envelope.

Also PO Akley's book has a lot of information but a number of the loads are on the extreme high end and should be taken with a very large grain of salt.