Morning All! I am looking at building a 6.5 on a remington 700 long action. I have narrowed it down to .260AI, 6.5PRC or 6.5x55 Improved and I am leaning towards the 6.5x55. My problem is that I am am seeing 6.5x55 Ackley Improved, 6.5x55 BJ AI (Bob Jourdan Ackley Improved) and regular 6.5x55 Improved. AmmoGuide is where I get my initial info and they only list the 6.5x55 Improved. It has a 54 degree shoulder which I like more than the 30 or 40 degree shoulder of the other two but I cannot find any other sources that list a 6.5x55 Improved with a 54 degree shoulder.
Anyone have any insight into the 6.5x55 confusion? I am thinking that 54 degree shoulder may give me a little more barrel life over the 30 or 40.
Thanks!
Mark
I am not a fan of the AI stuff, the claims for the cartridges are primarily hype. Take a look at the increase of powder and if it is in single digits you will not actually have much velocity increase over the parent cartridge. How Ackley and Ackleyites got their velocity increases was due to pressures increases 15,000 to 20,000 psia above the parent cartridges.
Shoulder angle will do nothing to increase barrel life. What matters is the pressure you are operating at and the amount of powder you burn in the tube. Back in the day, there were lots of unsubstantiated claims about shoulder angles, and they were all psuedo science.The higher the pressure and the more powder, the shorter the barrel life will be.
You want super high velocities, go for the 264 Win Mag. You will get about all the velocity you can get, and your barrel life will be around 700 rounds. One shooter I met, his 264 Win Mag key holed around 800 rounds. You push that 6.5 mm bullet in a smaller case your barrel life will be about 1400 rounds.
I think my velocities with a 20" barrel are just fine with the parent cartridge and is plenty accurate:
The greatest increase in velocity came from shooting this cartridge in the 29" military barrel. Velocity was 200 fps faster with the same military ball ammunition in a 24" barrel. That is a real increase without having to pop primers.
Notice, same load, same barrel length, two different velocities. The world is not only queerer than we imagine, it is queerer than we can imagine.