My experience is with 257RAI, and I cannot get perfect cases on the first shot.

I have tried about 100 things and took volumous notes.
I have settled on 10 gr Unique and Cream of Wheat to get an 80% shoulder. Then I load with the full AI load and get full accuracy on the next shot.

The amount of powder to push Cream of Wheat is not sensitive. I can use 20 gr Unique with little difference. I can also use Bullseye or 2400.

I just don't feel like burning out my barrel for an inaccurate shot.

This week end a friend of mine at the range had a 2.5" 41 shot group. THat is how he forms brass, but I prefer the creame of Wheat.

For a .223 case, with half the case capacity, I would use 5 gr of Unique and cream of wheat. If at a range where you can't shoot straight up, put a dab of Ivory soap on the case mouth to keep the cream of wheat from spilling in the action.

For the 223AI, Clarks method will certainly work but it is not necessary. Firing factory 223 ammo will result in perfectly formed 223AI cases.



Even better, use a max 223 load out of the manuals, and seat the bullets about 0.005" into the lands. This results in a perfect 223AI case every time. By using max 223 loads, the accuracy should be quite fine as well. When you back off from that full load the accuracy seems to drop off.



Fireforming using actual ammunition is also called "practice" by some shooters. A gopher won't know he was just shot with a fireforming load. Re burning out barrels with "inaccurate shots", my rifle averages about 3/8" for 5 shots at 100 yards with fireformed brass, and about 1/2" with the fireforming loads. You'll have to decide if the extra 1/8" is important to you. The secret is using the max 223 load, and not a reduced load.



When fireforming, I've had best luck with Winchester brass. Others seem to like Remington.



The 223AI is a great little case. Mine is built on a short 700 ADL. If you haven't bought dies for it yet, please take my advice and buy the Redding bushing neck-sizing complete set. I get best results with the .245" ti ni bushing. The Titanium nitride bushing lets you neck size without lube.



If you buy once fired brass from someone like www.brassmanbrass.com (much cheaper), you will need the body die as the once-fired cases will likely be too large to fit in the nice Cooper chamber.



It's a good die set. With no case lube needed, and a powder measure, you can turn out a lot of rounds in a hurry.



Here's that set in Sinclairs catalog.



http://www.sinclairintl.com/cgi-bin/category.cgi?category=REDIREDS&item=RD78XSD2&type=store



You need to order the bushing die for the sizer die seperately. Part number RD76245.



Hope this helps.

I am new to board. Please give me advise on a cooper 21 in 223 AI , I am planning on buying. Should I use factory ammo to fireform cases or buy virgin or once fired brass and load my own to fireform?? Which wiould be more economical and would accuracy in general be adequate during fireforming to use for general varminting?? Any thoughts on rifle (ie trigger adjustment) would be greatly appreciated. thanks much, Doc Stone