In my last post I mentioned that the dies for this project have been acquired. They are manufactured by Redding, and consist of a full length resizing die, a neck sizing die, and an adjustable setting die.
The first thing I needed to do was disassemble each die, then clean them. The manufacturer recommends a gun cleaning solvent, but I used a slightly different method, which consisted of hot water and Dawn dish detergent. After cleaning them I rinsed them with boiling water. The boiling water will rinse all the detergent. oil, and crud from the die. The temperature of the water will heat the steel high enough to evaporate the water preventing it from rusting.
Then it is necessary to apply a light coating of lube on the inner surface of the die to prevent rusting, and to make the sizing operation smooth. This lube should be the same as what will be used for the normal sizing operation.
Next the setup of the press.
The press I use for this project is a Lyman Crusher, which used to be called the Orange Crusher because it was painted Orange, but apparently some marketing genius decided that black would be a better choice. It probably saved them 2 cents a unit.
The neck sizing die was installed, and adjusted. This die, as the name implies, will only size the neck of the case. This allows a case to be as close to the dimensions of the chamber while still being able to be loaded and extracted from the chamber. Though this ”custom” size of brass will possibly not fit in some chambers.
My rifle being a standard production model with the regular barrel will have a chamber cut to the larger side of the standard maximum/minimum size for the 300 RUM.
Most all the factory ammunition produced will fit into almost all the guns made to the SAAMI designated dimensions. The different size chambers from one barrel to the next, though very minor is a factor in accuracy of a given rifle. With the case being almost the same size as the chamber the bullet will be more aligned with the bore of the barrel, this adds to the potential accuracy of a firearm.
When a person has a custom-made barrel installed one of the common practices is to have the barrel reamed to the minimum size of a given cartridge, and sometimes even to the point that only a certain bullet shape, and length will be usable. The rifle of this blog does not have a chamber cut in such a manner. Just about any factory round should feed, and function in it.
The brass has already been fired in this rifle, by only neck sizing the case it will have a tighter fit, and aline the center of the bullet to the center of the bore more closely. After the neck sizing the case was primed, then charged with a powder load of 78.0 grains of IMR 4350. The next step was to seat a 175 grain Nosler Custom Competition bullet, using the bullet setting die that has a setting adjustment micrometer which allows the bullet to be set at a precis depth in the case neck.
I chose to seat my bullet at a depth that allowed me to have an overall length of 3.555 inches. This is 0.045 of an inch from the maxinum length. It will allow the use of the magazine ether the original, or the aftermarket on that is currently being used.
- .300 Rum
- Case Norma once fired
- Primer Fedarel Large Rifle Magnum No. 215
- Powder IMR 4350 78.0 grains
- C.O.A.L 3.555 inchs
Sorry for the slightly disjointed post, on to the results.