Bookcase time, what is a .30 DUN cartridge?
- Thread starter maple_leaf_eh
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maple_leaf_eh
CGN Ultra frequent flyer
Do you have a reference? A middle ground between 7x57 and 8x57?
What did he have his stamped again? 30 Hoyt? I like yours more! lol
maple_leaf_eh
CGN Ultra frequent flyer
A friend with access to a specialized library found a copy of the Oct 54 American Rifleman, and dropped a copy at my door earlier today!!!
The cartridge is an experiment from the fervid imagination of Roy Dunlap, and he wrote about it in subj publication. The T48 7.62x51 cartridge was just new, and there were dissatisfactions about the accuracy at 300m in international matches. Which now we understand as not the case's problem, but the balance of bullet dynamics and powders. What did Dunlap do? He threw out the business of tuning and went to a clean sheet new invention. The case he came up with was 57mm vs 63 for 30-06 and 51 for 7.62. It has the long neck of the 30-06, and more powder capacity to overcome the 7.62x51's believed deficiency. He cut the chamber by short-stroking a 30-06 that 6mm difference. Duh. The case is made by shortening a 30-06 as a second choice, but Dunlap preferred to blow out the 7x57, or maybe squeezing the neck of an 8x57. He described machining the dies 6mm shorter.
What I find now is now called .30x57, and it is a common enough cartridge with the cast bullet community. Nowhere else it seems.
The cartridge is an experiment from the fervid imagination of Roy Dunlap, and he wrote about it in subj publication. The T48 7.62x51 cartridge was just new, and there were dissatisfactions about the accuracy at 300m in international matches. Which now we understand as not the case's problem, but the balance of bullet dynamics and powders. What did Dunlap do? He threw out the business of tuning and went to a clean sheet new invention. The case he came up with was 57mm vs 63 for 30-06 and 51 for 7.62. It has the long neck of the 30-06, and more powder capacity to overcome the 7.62x51's believed deficiency. He cut the chamber by short-stroking a 30-06 that 6mm difference. Duh. The case is made by shortening a 30-06 as a second choice, but Dunlap preferred to blow out the 7x57, or maybe squeezing the neck of an 8x57. He described machining the dies 6mm shorter.
What I find now is now called .30x57, and it is a common enough cartridge with the cast bullet community. Nowhere else it seems.
maple_leaf_eh
CGN Ultra frequent flyer
The final proof was discovered late last night. As I continue to empty my father's house, I've had to bring boxes from there to my home where I can work on them at my leisure. (( The lesson for every one of us is to be respectful of our heirs, and live organized lives! ** ))
I found two typed 12-point letters on Roy Dunlap's letterhead. Both addressed to my father by his nickname, and writing in a flowing but self-assured tone of voice. Dunlap specifically describes some features of the "30 DUN" and its measurements. He comments on its performance with various loads. There are other chatty remarks about mutual friends, name dropping of some of the other clients, and pleasantries about where to find good tea and gun stock wood. Oh to have been a fly on the wall for their conversations! The two papers are now stored TOGETHER with the ties and a couple of good quality copies of the American Rifleman pages.
Thanks for the helps!
** Pick an executor who knows you;
Put like things together;
If you take a gun apart, put it back together or at least bag or tie all the parts together;
If you have a broken piece that cannot be repaired, throw it out;
Ruthlessly assemble things into bigger and bigger themes; and
For Chrissakes put little kids' names on the backs of photos - especially your own kids!
I found two typed 12-point letters on Roy Dunlap's letterhead. Both addressed to my father by his nickname, and writing in a flowing but self-assured tone of voice. Dunlap specifically describes some features of the "30 DUN" and its measurements. He comments on its performance with various loads. There are other chatty remarks about mutual friends, name dropping of some of the other clients, and pleasantries about where to find good tea and gun stock wood. Oh to have been a fly on the wall for their conversations! The two papers are now stored TOGETHER with the ties and a couple of good quality copies of the American Rifleman pages.
Thanks for the helps!
** Pick an executor who knows you;
Put like things together;
If you take a gun apart, put it back together or at least bag or tie all the parts together;
If you have a broken piece that cannot be repaired, throw it out;
Ruthlessly assemble things into bigger and bigger themes; and
For Chrissakes put little kids' names on the backs of photos - especially your own kids!
