243 Ackley. Project getting closer, experiences and advice welcomed

Hi all and thanks in advance.

I am haf-way through a 243Ackley build with a new 1:7.5" twist True-Flight on a Sako 85 action. Standard Sako sporter profile but a tad longer at 22 or 23" depending on how it feels. Standard stock but it will be bedded.

build is for a fairly lightweight carry/walking rifle that is versatile. I'll be interested to see what I can get it to do out long on paper as well for some fun.

The Ackley chamber is purely for a bit better case life as the performance of a standard 243W is everything I need (albeit with heavier pills as an option) but I want by cases to last a bit longer so....Why not.

I have some Lapua brass, some 103gn Hornady ELD-X 108gn Hornady ELD-M and 105gn(I think...) Lapua scenars to try.

I have AR2208, AR2209 and AR2213sc to try

No primers yet (Will prob try S&B I think)

This is an ivitation for any of you experienced with the 243AI to offer up any tips or advice as the chambering is a new one to me.

Anything is welcomed from fireforming experiences/advice to pet loads, pills (for hunting) powders or hunting stories. Bring it all on.

Thanks in advance and kind regards, Luke

Luke, I see on your other posting you are neck turning your new Lapua brass. Is this just to tidy it up or are you turning for a clearance based on your reamer drawing?

@zimmer Neck turning into the shoulder helps prevent donuts in an AI case.

My load for the last many years is Berger 105 VLD in front of some N560. Barrel is 23" and its pushing 3180. Barrel life is better than expected. getting close to 1000 rounds and the throat looks like it will do plenty more. There has been no drop off in accuracy or velocity and no change to seating depth. lapua brass is on the 9th cycle but Im ditching some now that are getting loose in the primer pocket. There is some temp sensitivity with N560, Iv got it in the balistic app as 1.2fps/deg IIRC.
When its rebarrel time I will defiantly stay with the cartridge, its a great all rounder. I think Id try RL23 or maybe 26.

I neck pre-turned my 6.5x55 SM brass for my AI but not primarily to prevent donuts but due to very tight neck (ridiculously tight) clearance which was fashionable at the time. I did cut into the shoulder which yes, wilI have prevented initial donuts.

I have never experienced donuts developing after several firings. The AIs, well mine at any rate, virtually don't brass flow. I have hardly ever had to trim for length.

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Originally Posted by zimmer

Luke, I see on your other posting you are neck turning your new Lapua brass. Is this just to tidy it up or are you turning for a clearance based on your reamer drawing?

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Purely to ensure that I am starting with 100 pieces of brass with (as close to) identical necks as possible. They only needed a very light cut to even them up.
I did not know about neck turning helping with donuts. As a result I pulled up 20 thou or so short of the shoulder junction.

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Originally Posted by sneeze

@zimmer Neck turning into the shoulder helps prevent donuts in an AI case.

My load for the last many years is Berger 105 VLD in front of some N560. Barrel is 23" and its pushing 3180. Barrel life is better than expected. getting close to 1000 rounds and the throat looks like it will do plenty more. There has been no drop off in accuracy or velocity and no change to seating depth. lapua brass is on the 9th cycle but Im ditching some now that are getting loose in the primer pocket. There is some temp sensitivity with N560, Iv got it in the balistic app as 1.2fps/deg IIRC.
When its rebarrel time I will defiantly stay with the cartridge, its a great all rounder. I think Id try RL23 or maybe 26.

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This is awesome information and very encouraging . Thank you!

If prepared to sacrifice a case, then the top half may be sectioned so that the shoulder can be accessed and the thickness measured and compared to that of the neck. It would give a feel for how much or how little could be removed from the shoulders and give confidence that the whole neck is not going to rip off on the first firing because – after somewhat excessive turning – they are just being held to the rest of the case with brass foil.

Should you decide – due to OCD and the reloading experimenter's ever-present fear of the dreaded donut – to re-turn the whole lot again for the sole purpose of running the cutter down onto the shoulder, then remember too that the parent case in the improved chamber is set to headspace between the boltface and the neck-shoulder junction (usually for a 0.004" crush fit) and that this will be reduced in part (or entirely) by cutting the shoulder back. No point in reducing the life of the cases by thinning the case walls down at the heads unnecessarily when fireforming through incorrect headspacing.

Alternatively you could turn into the shoulders after fireforming since the newly improved cases will then continue to headspace on the unmodified outer shoulders. You’d need a cutter with a 40° chamfer. The unknown is what donut if any has already been formed on the first firing. Will it make a difference? Who can say? The donut is like the fear of the unknown. They could turn up at any time and spoil your Christmas:(

Good advice from Puffin on sectioning a case even though we hate losing a case.
I never did that with my Swede. I made a guestimation of how far to cut into the shoulder neck junction.
Worse still my cutter at the time also was not profiled for the angle. I have since got cutters for most shoulder angles.

Quote:

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Originally Posted by Puffin

If prepared to sacrifice a case, then the top half may be sectioned so that the shoulder can be accessed and the thickness measured and compared to that of the neck. It would give a feel for how much or how little could be removed from the shoulders and give confidence that the whole neck is not going to rip off on the first firing because – after somewhat excessive turning – they are just being held to the rest of the case with brass foil.

Should you decide – due to OCD and the reloading experimenter's ever-present fear of the dreaded donut – to re-turn the whole lot again for the sole purpose of running the cutter down onto the shoulder, then remember too that the parent case in the improved chamber is set to headspace between the boltface and the neck-shoulder junction (usually for a 0.004" crush fit) and that this will be reduced in part (or entirely) by cutting the shoulder back. No point in reducing the life of the cases by thinning the case walls down at the heads unnecessarily when fireforming through incorrect headspacing.

Alternatively you could turn into the shoulders after fireforming since the newly improved cases will then continue to headspace on the unmodified outer shoulders. You’d need a cutter with a 40° chamfer. The unknown is what donut if any has already been formed on the first firing. Will it make a difference? Who can say? The donut is like the fear of the unknown. They could turn up at any time and spoil your Christmas:(

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Awesome! Thank you! I think at this stage I will leave them as-is with the turning very minimal and not into the shoulder. After attempting to fireform with the no-bullet 70% case capacity Bullseye method I will see how it all looks. There are a lot of "firsts" for with this cartridge and handloading regime.
Please keep the awesome info coming!

I was not initially happy with the fit of the neck turning mandrel into the neck of the cases, it was a little bit loose for my likings. So I used a Lee collet neck sizer to bring the necks down so they were a nice clearance fit. I then turned the necks as previously mentioned. My plan is to use a body die to bump the shoulders, then a Lee Collet neck die and if I do not have perfect neck tension I have a Sinclair expander mandrel die to get them just right.
I realise there are a lot of processes in this but it feels like it should work well. Any thoughts from the jury on this process? Am I making too much work for myself? That's a pretty silly question really when it comes to handloading for Precision but I have so much to learn I am keen to hear your opinions.

@Luke777 - what was the the decision process you went through to end up at the 243AI as your calibre of choice?

I'm curious to know what your criteria were - ultimate performance? Something different?

And 'because you can' is a very valid answer! :)

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Originally Posted by Steelisreal

@Luke777 - what was the the decision process you went through to end up at the 243AI as your calibre of choice?

I'm curious to know what your criteria were - ultimate performance? Something different?

And 'because you can' is a very valid answer! :)

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I wanted a good all-rounder (excepting buff and scrub bulls) for pack hunting here in Australia and the 243W has proven over and over to be one of the top picks along with all the other valid and capable cartridges we all know and love.
But I wanted to be able to fling slightly heavier pills and as a result, found that the vast majority of factory barrels may have a borderline twist rate. So I decided on a custom pipe from True-Flight with a faster twist. Well one thing led to the other and while I was at it I decided to go the Ackley Improved route PURELY to decrease case stretch and hopefully lengthen the life of my brass and decrease the need to trim. I'm not looking to eek out an extra 100ft/sec from the cartridge.
I realise I made a lot more work and expense for myself initially with dies, forming etc but I am a tinkerer at heart which is another big factor in the equation leading to my choice.
Ironically I have never owned a 243. I have 2x 6.5 Swedes, a .308Win, a .223 Rem.
I tossed up the venerable 7-08 and 260Rem as well as the 6.5Creed and 6mmCreed but in the end I found a nice Sako 85 in 308 which makes the barrel change nice and easy and if I ever need to shoot factory 243 ammunition in a pinch you can get them pretty much anywhere in my neck-of-the-woods.

I also have to confess that I love the (dare I say it)...look of the cartridge. The sharper shoulders and less body taper just look lovely. Like a mini 280 Ackley..

So...I know I could have made "smarter choices" for a hunting rifle with a 23" barrel but as you mentioned "because I can" snuck in there a bit too:)

I hope I don't regret my decision and If I do I am sure I will find a new pipe to swing onto it after the barrel is burned out in 1000 rounds like many people have implied may happen :)

I'm really looking forward to getting it all together and seeing what it (and I) can do. I might even try to hit some paper out long with it one day once I get it a bit sorted. That would be fun.

I'm probably going overboard with my handloading (neck turning and annealing etc) but I love to try and do my very best for the animal so consistency, first shot accuracy and terminal performance are very important to me.

I love to learn.

I haven't sectioned a case for that reason but I might at some stage . The neck is .014 and the shoulder will be thicker again which is enough for me to take a few thou out of the junction with confidence. You can get the rifle throated so the bearing surface of the projectile is above the neck/shoulder junction in the case then any possible donut wont influence neck tension. To fire form I shoot the VLDs with a .020 jam anyway so I just use the same load. Accuracy can be very good . It wont be quite as good as something with a tangent ogive like a sierra gameking but a little initial stretch doesn't concern me, as long as the sizing die is set up correctly then any further stretch will be prevented.
This is a 6.5x284 case , I had donut issues with this as well. I use 40deg cutter for this.

Attachment 156378

Sneeze that is nicely done. Great info mate it all makes sense too.

I'm inclined to think that it might just be a common misconception that shoulders are always thicker than necks. The cases I have recently sectioned all had shoulders at the same thickness as the necks.
I'm not sure either that having the shoulders at the same thickness as the necks – or turning them thinner again – is a guaranteed way to prevent donuts. It could be that the neck-shoulder junction is a natural point for the build-up of brass on firing irrespective of the thickness of material from which it is derived.

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Originally Posted by Puffin

I'm inclined to think that it might just be a common misconception that shoulders are always thicker than necks. The cases I have recently sectioned all had shoulders at the same thickness as the necks.
I'm not sure either that having the shoulders at the same thickness as the necks – or turning them thinner again – is a guaranteed way to prevent donuts. It could be that the neck-shoulder junction is a natural point for the build-up of brass on firing irrespective of the thickness of material from which it is derived.

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Thats interesting, what cartridge and brand? Iv encountered thicker shoulders when necking up, the thicker brass pushing to the outside that needed turning off and have assumed they were all the same.
Donuts are bit of a mystery all right , I think you are correct in the junction being a point of buildup. Iv found they mostly form on the first or second firing and that relieving that area alleviates the problem for the life of the case. I tried inside turning on my 280ai but wasn't as successful.

Lapua 8x57is

Any opinions on Powders to start development with in the 243AI? I am in a hot climate but have a tendency to go with the ADI powders historically which are pretty good with regards to temperature sensitivity.
I'm all ears.