I'm having my chamber reamed to .223 AI and I'm looking for an appropriate fireforming load. Not doing any tight neck so I don't think I'll need to turn brass. Will I need to look for new AI dies or will a std neck sizing die work?

Thanks

I haven't loaded for the .223 Ackley, but have loaded some other Ackley cartridges. I don't load anything special to fireform, a good factory load will fireform and almost never lose a case. When they fireform, most are a little sticky coming out of the chamber, so I'd be real suprised if the std. .223 neck sizing die will work, at least for the first loading.

Iused standard 223 loading data to fireform my 223AI and used Lee Collet dies for loading. Worked great.

For fireforming I always use Win. USA factory loads. They are supriseingly accurate while fire forming too.

I use 25 gr of Accurate Arms 2495BR with a 50 gr Rem PSP bullet seated out into the rifling. Another alternative is 24 gr of IMR 4895 with a 55 grain bullet. Sierra tech line recommended that one. In fact, they suggest using IMR4895 for all fireforming. The reason given for seating the chosen bullet into the rifling is to keep the case head up against the boltface.

The only kind of neck sizing die I use is the Lee Collet. In that application the standard 223 Rem is appropriate. 223AI cases last almost forever using only the collet die and moderate powder charges. Happy shooting!

Thanks, I'll be looking for something in Redding, Forester or Hornaydy dies in AI Any recommendations?

The Redding number is 80907 for F. L. Die Set. That is for 223 Remington IMP 40 degree. Takes shellholder #10. Whichever brand you finally decide on, make sure it has the same shoulder angle as your chamber. Not all improved cases are 40. There are 28, 30, 35 degree. I specifically requested my smith to chamber my rifle for the 40 degree shoulder. He only sells one brand of reloading dies: Redding.