I spent a few days on making the form dies and reloading dies for the project gun. It takes quite a few steps to shorten a 408 case and neck it down to 30cal. First i anneal the case to where the shoulder junction will be, then i run it into my first form die that takes the exsisting
shoulder down to .500" in dia. Second die takes it down to the 408 neck size. Third die then goes down to 375 neck size, i anneal after this step. I then shorten the case to 2.160"
Final form is done by using the seater die. I put the case in a special holder and chuck it in the lathe, then the case is inside reamed to .306". While its in the case holder i turn the neck dia to
.336" Trim to final length of 3.150" I anneal one last time, They are now ready for fire forming. I use full loads as there is not much to change as the angles on the body are the same as a 408 case, just the shoulder angle is changed a bit.
Test loads:
1st fire form test,
Retumbo
80 gns 207 horn Amax bullet set .030 from lands
2550 fps ave (light load)
no targets were used
2nd test fire forming
Retumbo
85 gns 207 Amax 2670 fps still light load, powder too slow
3rd test fire forming
H-1000
80gns 207 Amax 2650 fps light load group size .650"
82gns " " 2710 fps moderate load group size .680"
85gns " " 2750 fps " " group size .750"
4th test
H1000
82 gns 200 SMK 2755fps moderate load group size .302
(First loads with fired cases)
85 gns 200 SMK 2795 fps Moderate load group .310"
( these groups are shot with clean barrel and two follow up shots)
Still the loads have not come close to toping out for pressure signs, i
will move into a bit faster burning powder. The case will hold 87gns of
H-1000. A faster powder should get me into the 2800 fps area.
I did some 500yd tests but it appears the 8 twist barrel is having issues with
the shorter bullets im using for case work and barrel break in. This is designed for
the HAT 210gn AT bullets, they are almost 2" long.
This is my first attempt in shooting a specialty pistol, i have an issue with an
improper rest and rear bag system. The electronic trigger works great and helps
a lot with the wiggly bench i have. When i gets time i am putting in a concrete setup.
I will get a few pics of the forming process and finished cases.
Dave
