23 November 2010
Jeff - that is a very interesting ctg.
I made up a similar round, almost identical, back in about 1983, except that mine uses a 1.6” case & a .308” barrel. I used the top 1.5” of a standard .30/06 reamer, so it has a .448” base and .441” shoulder with the attendent long .30/06 neck length. Yours looks quite similar, however the water capacity of mine is 33.0gr. to the bottom of the neck of a shortened and fire formed Fed .303 case.
The reason I built mine was to use the 22” end section of my Palma Trophy Match M70 barrel that was badly worn out after 15,000 rounds. After I cut the barrel, re-threaded and chambered it to a Mauser action, the lands of the 4 groove barrel were starting to be visible ahead of the new chamber. I also found I could use .35 Remington brass iwith a standard 8 Mauser bolt, or .303 brass with a magnum bolt as I had both bolts for that action with identical headspace measurements.
With jacketed bullets, ie: 165gr. Sierra HP, I got 2,465fps, an excellent deer load, my primary goal for the barrel. With light bullets of 110gr. I achieved 2,900fps for shooting rats, while 130gr. ran to 2,650fps & actually shot the best, so far. The heavier 180gr. at just over 2,000fps was a moderate load, not max, but I expect around 2,250fps would be. This is just preliminary load development. Accuracy has been .4” to 1 1/4” depending on bullet and load.
I had just started experimenting with cast bullets, when I needed the action for my Daughter's first rifle. I now have a short, small ring 98 action, probably Mexican that will get that barrel, when I get around to it.
I called my version the .30/03.
I should note there, that the easiest method of making cases, is to shorten a .30/06 die & chamfer the base. I then lube a .303 case and run it into the die, without a neck expander. Trim to length then turn necks and size again with the expander in place & they are ready to load.
This is a 1 step operation without any case loss if new of once fired brass is used.
This thread now has me interested in my .30/03 again. Thanks Jeff. I've a number of .30 cal moulds - just wish it wasn't -30C outside. Bit chilly for casting today.
The 125gr. TNT's haven't been tested yet, but they looks so good, they MUST shoot.