WTB - 358 Premium Bullets for Testing

[5shot]

Thanks to Truck Driver, I was able to check the 250 PT today. To my surprise, it requires a shorter throat than the 250 Hot Cor. Roughly 0.065" by my unscientific method. Probably a tad more, as the nose on the Speer got damaged when I had to tap it out of the bore on the first attempt.

I can actually seat the 250PT to 3.330" and chamber a round - just shy of the 3.340" OAL. My magazine will allow for a bit more than that, so I think I will end up with somewhere in between, so I can seat both out to just touch the rifling. The 250PT will end up being just over the recommended OAL and the 250 Hot-Cor will be just under.

One other thing I noticed, is that if you plan to shoot the 225AB, you pretty much have to give up on having the others seated to take advantage of the full length of the magazine. In my short throat 721, I can easily chamber the 225AB at an OAL of 3.340". If I lengthen the throat to use the other bullets, the AB will have quite a jump.

 

[truck driver]

ABs like a lot of jump. My AI has a long throat and I can't reach the lands with any bullet.
I'm getting ready to do some work with the 225gr AB and I'm sure I will have to seat it deeper than the 225gr PT to get a tight group.
Don't get caught up trying to reach the lands with the AB they love some jump .100" and sometimes more.
My 200gr AB load has almost .200" jump to the lands and it is a sub 1/2" load.
So if your planning to use the other bullets I would lengthen the throat so I could take advantage of the magazine length and get the extra case capacity.

 

[5shot]

Thanks. I plan on sending a 250PT dummy round, seated to max magazine capacity (with a bit of clearance for smooth feeding, of course). This will be my primary load, and then everything else will be what it is.

Good to know about the jump and the ABs.

The 721 he rebarreled for me has a magnum length magazine box from the factory, so I can seat any bullet out to touch the rifling, but the throat is so short that it doesn't matter. I am going to have him cut it deeper when I send him the M70.