I have a 223 Ackley improved i purchased 200 factory Lapua 69grn rounds to fireform the brass all cases have now been shot 3 times I have annealed after each firing with an AMP annealer and I’m getting split necks any idea of a cause ? My reloads are 26grns of N540 with a 77grn Sierra head
223 cases split necks
- Thread starter Alan2791
- Start date
billgatese30
Well-Known Member
How hot were the necks getting during the annealing process?
One on top of two
Well-Known Member
Defo need to anneal before fireforming , with my .223 AI even with brand new brass i still anneal first .
Also with new brass my first load is faily tame (25.3 grns of N140 ) the anneal again and then i do hot load .
Also with new brass my first load is faily tame (25.3 grns of N140 ) the anneal again and then i do hot load .
I sacrificed a case in the amp and got a code
Possibly your die is not a good match to the chamber. When I had a 243 Ackley, I got a full length resizing die made from fired brass.
Secondly, have you measured the diameter of fired necks versus sized necks?
Regards
JCS
Secondly, have you measured the diameter of fired necks versus sized necks?
Regards
JCS
Definitely get the neck measurement after firing.
Just want to check you haven’t turned the necks?
billgatese30
Well-Known Member
Ok, not sure how the AMP works, was just wondering if they weren't reaching critical temperature and being fully annealed. As said I would measure fired vs sized neck diameter.
No neck turning been done
Just a quick look at your photo kind of leads me to suspect you have a very generous Ackley chamber. You can see the line/ring on the lower part of the neck, where it isn't (apparently) being supported by the Ackley'ed chamber. That doesn't really answer the cause for the spilt necks, but it does imply something is wonky with the chamber. At least in my mind....
Was this rifle barrel chambered as a .233Ackley? Or was it originally a .223 that was reamed out to Ackley dimensions?
Was this rifle barrel chambered as a .233Ackley? Or was it originally a .223 that was reamed out to Ackley dimensions?
It was a 223 reamed out to an Ackley will this cause problems..
It depends. If the neck diameter is generous, then perhaps the case necks need to be resized in stages. Keep in mind that 223 Ackley and most other Ackleys don't have a SAAMI spec.
Regards
JCS
Are you annealing before or after sizing? Annealing both before and afterwards will help. You should be able to see the brass glow red hot momentarily during annealing.
Splits form via a process know as fracture toughness, where flaws in the material such as nicks and dings propagate into a split. You can reduce the probability of this by reducing the material hardness via annealing and reducing and flaws prior to split growth via trimming.
Splits form via a process know as fracture toughness, where flaws in the material such as nicks and dings propagate into a split. You can reduce the probability of this by reducing the material hardness via annealing and reducing and flaws prior to split growth via trimming.
Thanks I’ll start annealing them after sizing see how they go I was beginning to think faulty brass
6.5-06 TIKKA
Well-Known Member
A few ago I had the same issue with neck splitting after 1st firing.
6.5x284 Lapua brass.
I sent the cases back to Lapua for investigation.
Their conclusion was the brass was too hard from them in manufacturing.
So maybe nothing you have done....
6.5x284 Lapua brass.
I sent the cases back to Lapua for investigation.
Their conclusion was the brass was too hard from them in manufacturing.
So maybe nothing you have done....
I suspected as much. It can be a problem if they allowed the reamer to wallow out the neck.
That being said, I still think there is an issue with the chamber being slightly too deep.
As a recommendation, I'd suggest you conduct a simple test. Load a .223 case with a mild charge, and seat the bullet long, so it is in the lands/grooves. This will allow the case to remain against the bolt face as ignition happens, and limit case growth. Then measure the case length and shoulder length against some of the factory .223 cases you shot/fireformed in your chamber. This will give you a very good idea of what is happening in your chamber.
Similar threads
