hey there,
i know it may not sound right but firing factory 25-06 ammo in the ackley chamber is how you do it... in fact, and correct me if i'm wrong, Ackley specifically designed the AI chambers so that they would fire the factory parent cases safely incase the owner ran out of fireformed brass.... if the owner was out on a hunting trip and lost or ran out of loaded AI ammo they could go down to the store and buy some factory for it...
if the chamber was headspaced correctly the factory ammo should still contact the front of the chamber high on the shoulder near the neck junction...
that being said i have had some factory ammo ( I think it was winchester,) that was at the very low end of headspace specs and the rounds would kinda slump in the chamber and when it fireformed it had a bulge on one side of the case because the case wasnt sitting concentric in the chamber...
now as far as my steps for fireforming go... I decided i wanted to use lapua brass in mine and lapua doesnt make 25-06 so i am stuck neck sizing down from 30-06 brass...
step 1: run 30-06 brass through thandard 25-06 die leaving the last ~ 10 thou of the neck unsized to create a false shoulder to make sure i get a real good seal at the neck shoulder junction
step 2: trim the newly formed 25-06 brass to standard length
step 3: turn the necks to 12 thou thick (probably not needed as i dont have a tight chamber but i do it any way to make them all uniform)
step 4: load with a bullet and powder of your choice at the high end of standard 25-06 load recommendations as per your favorite manual's recommendations for said bullet and powder and fire away... i use 90gr sierra hp with reloader 19.... absolutely insane gopher destruction while fireforming cant be beat!
(lots of other guys will use a cream of wheat technique to fire form using really fast burning pistol powders, i have never tried it but you should be able to search and find lots of info on this sight about it)
step 5: inspect all the cases for split necks etc (never had one with the lapua brass so far) then i neck turn them to shave off any lopsidedness in the necks (once side of the wall thicker than the other) again and make sure i make a slight cut into the shoulder to help remove excess brass from the neck shoulder junction to prevent the formation of the dreaded "donut".... (search donut as related to fireforming ackley brass and you'll get a lot of info and opinions on the topic)
Step 6: work up a load... mine like 115 berger vld and reloader 25....
now if you don't wanna go through all that to work, i'm sure you will be able to make the thing shoot starting with factory 25-06 ammo and remove steps 1-4 of my process...
good luck
orch
