09-10-2013, 02:22 PM
woohoo Wrote:What load are you using to push a 123 to 2650fps out of a 16" barrel?
The photo of the button you posted is really a Hybrid 5R like we use. An Obermyer or Rock has a different land shape, angled but different than shown. I have not bore scoped a Satern to see if it is like the Obermyer or if it is a Hybrid. There were posts on the old Grendel forum as far back as 2007 showing the velocities possible with 5R barrels but it is more than just the shape. Bore area, groove diameter and land to groove ratio all play a part in accuracy, pressure produced and velocity. Tweaking all of those can get you a barrel that is much faster but not so accurate or super accurate and a little higher pressure, just depends on what is more important to the person designing the button.
Maybe Bill A. can chime in but it looked to me like the less expensive AA barrels may be a 6R. I didn't spend a lot of time with it or video it but through the borescope the lands looked like they had sloped sides.
These are MAX loads in my 264 5R barrel with a .100 freebore. Some of the max loads shoot 1 MOA easy enough if that is good enough to hunt with. To find 1/2 MOA most need to be dropped 1/2 -1 gr.
123AM 2.3 748.. 31.5 2643 CCI450 20" max charge
123AM 2.3 335.. 29.5 2672 CCI450 20" max charge
123AM 2.3 4895 29.5 2650 CCI450 20" max charge
123AM 2.3 530.. 28 2682 CCI450 20" max charge
123AM 2520 31 2660 BR ........20" max charge
You missed something those are factory Amax out of 24in barrels.