Re: 300 Ultra Mag Questions
Charter, welcome to the site.
I am using a 178 A-Max at 95-96gr RL25 and getting over 3260 average at 61 -65k psi at 3.655" OAL in my gun. This bullet is real accrate and has created less psi on the Oehler 43 at the same velocity than all the others too, the same was found in my dads 300wsm also.
The 220gr SMK is over a max load of 85-86gr of RL25 at just over 2900 fps and 65k psi at 3.710" OAL, which were single fed only.
The loads used a 210m primer and a 26" barrel.
The load data for the 220 was attained from a Sierra tech.
I cannot remember where I got the starting load for the 180's, I believe it was a consenses of several sources though.
The 180 shoots flatter at 500 yards by 2 moa, at 700 by 3 moa and at 1000 by 4 moa, but the 220 has an advantage in energy through the whole range which actually gets a little better along the way because it's velocity decays at a slower rate.
The impact velocity is slower at longer range and pass through shots are more common because of less expansion, a more conventional bullet will hold up better than one would think, and premiums for this reason, in my opinion are rarely needed and work more like solids. [img]images/icons/wink.gif[/img]