30 maximum load data ?

[BoredinLC]

A little time came available to test the “300 BO FL die” theory, and if you do attempt to form the shoulder on the 30 Max with one, it will be approximately 3/8” above the shellholder to get proper headspace on the new shoulder….. No biggie.
As with any firearm of this type, sneaking up on the shoulder by gradually setting it back until the gun closes on the newly formed case with a little effort to insure a “tight” fit is best to fire-form.

[BoredinLC]

Well, full-length sized Maxi cases in a 300BO die is obviously not correct.
Dropping a 300BO case into the chamber leaves the rim about 3/8” deep, so using a 300BO die to push the shoulder back to the proper length is feasible to fireform but the “full-length sizing” suggestion was obviously wrong.

On the other hand, a 7.62x40 WT case rim very close to a proper headspace position, almost flush with the chamber’s mouth.
It is a decent starting point to fit the case properly using Maxi brass, when time permits.

[dhagerty40x]

to make your job easier, You can get the dies from CH4D:

https://chtoolanddie.com/calibers/30Max

[aggshooter]

Interesting thread!
What's everyone's purpose for this cartridge? Silhouette? Standing gun with peeps? An "improved" 300 Blackout? Hunting? Something that falls between a BLK and a 30br with pressures suitable for TC frames?

Inquiring minds want to know!

[aggshooter]

Well, full-length sized Maxi cases in a 300BO die is obviously not correct.
Dropping a 300BO case into the chamber leaves the rim about 3/8” deep, so using a 300BO die to push the shoulder back to the proper length is feasible to fireform but the “full-length sizing” suggestion was obviously wrong.

On the other hand, a 7.62x40 WT case rim very close to a proper headspace position, almost flush with the chamber’s mouth.
It is a decent starting point to fit the case properly using Maxi brass, when time permits.

Have you tried starting with a common 7.62x39 full length die? I'm not at home to check, but IIRC I used one to do initial forming on the 270 max, after annealing of course. You may have to back it out a tad.