Dedogs her are a few pieces of info you may find useful:
Here is a book that is highly recommended if you don't have it already:
Designing and Forming Custom Cartridges for Rifles and Handguns - Ken Howell
http://www.huntingtons.com/store/product.php?productid=19665&cat=0&page=1
There are some comments in Donaldson's book on twist that are interesting. He was not a fan of fast twists, but of course that depends on the distance of interest.
Not directly on topic but of interest:
I also was going back through Donaldson's book and see where he had an earlier "Ace", a .250 Don-Ace. This was .25 cal from a modified 250 Savage: "length of 1.9170"(the .250 Savage measures 1.9127"), and a 30 degree shoulder. The case length in the Donaldson Ace over the parent likely comes from the act of moving the shouldder back. The Shoulder on the .250 Donaldson Ace has been pushed back to 1.400", and the case body having much of the parents body taper taken out. The .250 Donaldson Ace measures .4445" across the base of the shoulder compared to the .250 Savage's measurement of .4142".
Interestingly, the .250 DA was a hit in the early '50s bench rest crowd. It set a record in 1954 for 300 yards. I cannot find any load data for it but there are some used dies and rifles floating around. However, most information on this cartridge seems to have vanished, unlike some pretty obscure wildcats in various current publications.
He also has some other "Ace" cartridges he made along the way, one was based on a .257 Roberts.
Here is a book that is highly recommended if you don't have it already:
Designing and Forming Custom Cartridges for Rifles and Handguns - Ken Howell
http://www.huntingtons.com/store/product.php?productid=19665&cat=0&page=1
There are some comments in Donaldson's book on twist that are interesting. He was not a fan of fast twists, but of course that depends on the distance of interest.
Not directly on topic but of interest:
I also was going back through Donaldson's book and see where he had an earlier "Ace", a .250 Don-Ace. This was .25 cal from a modified 250 Savage: "length of 1.9170"(the .250 Savage measures 1.9127"), and a 30 degree shoulder. The case length in the Donaldson Ace over the parent likely comes from the act of moving the shouldder back. The Shoulder on the .250 Donaldson Ace has been pushed back to 1.400", and the case body having much of the parents body taper taken out. The .250 Donaldson Ace measures .4445" across the base of the shoulder compared to the .250 Savage's measurement of .4142".
Interestingly, the .250 DA was a hit in the early '50s bench rest crowd. It set a record in 1954 for 300 yards. I cannot find any load data for it but there are some used dies and rifles floating around. However, most information on this cartridge seems to have vanished, unlike some pretty obscure wildcats in various current publications.
He also has some other "Ace" cartridges he made along the way, one was based on a .257 Roberts.
