I lost 17 of 100 .17 Remington cases fired in a .17 Rem chamber on first firing to neck splitting and a few more thereafter. Observed a few creases in the brass vicinity of the neck shoulder junction as the cases came from the factory. Since the creases were small I decided to load and fire. Upon firing the first time, or second or third time, the creases split, showed some powder burn, and were rejected for reloading. My opinion, tis just a bit of factory defect. By Ackley Improving the case I would venture a guess that the brass is moving and stretching a lot further and thereby revealing any defects. A possible solution is to make .17 Rem AI from better quality brass, .223 (posibbly ending up with a short case) or .222 Rem Mag. Of course the downside of this solution is lots of case forming (and neck turning) and a smaller powder chamber defeating one of the purposes of AI.



To summarize, I would not base any wildcat on .17 Rem brass due to quality issues (and of course just 1 source of factory brass). The best solution may be to rechamber.

I split a bunch of 17AH firforming. I was using too light of a load. Anneal, Cut the max for the parent case back about 5% jamm the bullet and see what happens. OR You can set the barrel back and make a mack daddy 17 Mach IV.

Just an update ... yes anneal before fireforming works.
I use about 7gr.of Unique with cream of wheat and a wax plug ,I have done several cases like this and haven't lost one yet. I also noticed the small creases in the neck area of my new brass, the annealing process seams to be working great so far.