I got my new 17AH today, have some forming questions

[odinohi]

I recieved my Bob Green 17AH today. I am trying to get my Redding forming dies adjusted properly. Here is what I have done. First vafoxhunter sent me a fireformed case that he made into a modified case for my Stony Point tool. His rifle was reamed with the same reamer as mine. I used that case to setup my dies for a starting point. I formed one case with that setting and the bolt would not close when trying to chamber it. That first formed case measured 3.162" at the newly formed shoulder with my stony point headspace gauge. I turned Form die#1 down a bit and it did nothing to chage that measurment. I then started turning the Form and trim die down and it did start changing the measurement. I took it down to 3.156 and the bolt did close, but with some force. When I ejected that case I measured for the shoulder and it measured 3.152. I then turn the die a little more until I had a measurement of 3.153. This case seemed to chamber with a little crush and when I ejected it, it measured 3.152. After I ran them through my FL sizer the neck measured .190 The neck in my chamber was reamed at .193". I did notice that when I ejected the cases I chambered there was a slight flat spot on the mouth. What do you make of that flat spot? And is .001" of crush enough? Also, what would a good safe starting point be for a fireforming load with VV N120, Little gun, and H4227? Sorry for the long post, but I,m exited this project has finnally arived in my loading room. Thanks All, Tom

 

[CJ6]

17 AH ? is that 17 Ackley Hornet ? 3.15 case length is just a little off,should be around 1.40 +- depending on the reamer for the Ackley Hornet

 

[odinohi]

That is the measurment with the SP headspace gauge included. My case length is real close to 1.40. Tom

 

[CJ6]

The flat spot on the mouth might be from having a short chamber neck,your brass neck is to long for the chamber) I would Cerro cast the chamber and then you'd have a better idea of the actual chamber dimensions,then proceed from there........Custom or Factory I always Cerro cast the chambers 1st thing after I receive them

 

[CIA]

10.2 grains lil gun with a 20 is a good load. Work up to it. Should be close to full power load for fireform. Try small pistol primers for best accuracy.

 

[vmthtr]

Flat spot is from the ejector forcing case into side of action on eject???????? I used H110 for fireforming in mine when I had it. Will look in Kindlers book toniught for grains. saubier.com is a great place for small calibers also.

Mike