358 Hoosier Chamber Dimensions

[oldhoyt]

I'm trying to locate a diagram of the 358 Hoosier chamber. Anybody seen one? Thanks.

[cedarthicket]

For a print of .358 Hoosier chamber dimensions you can get a digital copy by contacting Pacific Tool & Gauge. You can email them at [e-mail] and request a copy of .358 Hoosier Print #35414 (superseded by Print Number D-32464.

They are open Monday through Friday from 6 AM to 4 PM Pacific Standard Time. Their phone number is 541-826-5808. Their web site is: www.pacifictoolandgauge.com/

[Deleted]

books.google.com/books?id=bjhy8uv196IC&pg=PA221&lpg=PA221&dq=hornady+custom+dies+.358+hoosier&source=bl&ots=STKPASxsCk&sig=qyKfkXJo_2oEtEHeflBXvv81hjw&hl=en&sa=X&ei=D4K6UK26B8iP0QHo3IBw&ved=0CG4Q6AEwCA

[cedarthicket]

A word of caution, drawings in Cartridges of the World (COTW) are only approximate. I believe the dimensions they do show are generally within a couple thousandths of an inch. Close, but no cigar. They are certainly not something to take literally and build a chamber reamer or set of reloading dies and expect interchangeability of rifles and loaded cartridges with chamber reamers and dies built from detailed drawings from Pacific Tool & Gauge and Hornady. Several critical dimensions are totally missing. For example, headspace dimensions and dimensions related to free bore/lead and throat are not shown. Also, some other dimensions need to be closer than those shown in COTW.

[oldhoyt]

Thanks guys. The dimensions relating to free bore/lead and throat are exactly what I am looking for. Are these standard, meaning are they established with the reamer, along with the rest of the chamber?

[cedarthicket]

Jan 27, 2013 12:09:25 GMT -5 oldhoyt said:

Thanks guys. The dimensions relating to free bore/lead and throat are exactly what I am looking for. Are these standard, meaning are they established with the reamer, along with the rest of the chamber?

Yes, all these dimensions are standard with the .358 Hoosier chamber reamer. If you should get a special reamer made with different dimensions, and depending upon the dimensions and amount of changes, you could possibly lose some interchangeability as noted in my previous reply.

[oldhoyt]

Thanks. Here's why I'm wondering about this.

I took a re-sized case that measured 1.800 and inserted a Hornady 180 Gr SSP just barely into the neck. I then chambered this dummy round. I could feel the bullet being pressed deeper into the case as I pushed the bolt forward and closed it. This round measured 2.590 COAL as I recall. AJ Brown recommends a COAL of 2.500 for this bullet. In my mind this means the bullet must jump .090 before contacting the rifling. I also figured out how much bullet was seated in the case with COAL of 2.500, and I can't recall what that was exactly. I do know that I thought there would be enough in the case to go to a COAL of 2.525 for the next loading, and see how they perform.

I'm wondering if anyone else is seating bullets out a little, based on the fact that there seems to be some room to do so, and I have heard that too much jump to the rifling is not the best thing for accuracy.

[Deleted]

Im no expert but believe that the bigger jump will created more muzzle velocity. So, you would want to tinker with the OL to get a balance between max. velocity and accuracy.

[oldhoyt]

I've reloaded some, but am also no expert. What I have read suggests that pressures can increase if there is not "enough" jump. I have read that around .020" jump is about right for a starting place for fine tuning. I can't load the bullets out that far and still have enough in the case for good neck tension and concentricity.

[Deleted]

I believe that most weatherby calibers have a long jump to get the higher velocities that hou see with them

[cedarthicket]

In designing the cartridge chamber reamer the free bore/lead and throat dimensions were chosen so that the loaded cartridges would chamber with readily available bullets of 180 and 200 grains weight, have adequate bullet seating depth to give good neck tension, and maximize the available powder space. Also, the loaded cartridges had to meet an overall length of less than 2.80 inches so they would feed properly from common short-action bolt rifles. The resulting design is somewhat of a compromise, but it allows excellent performance of all existing 180 and 200 grain bullets.

Bullets that I successfully used in chronograph work included the 180 gr. Hornady SSP Interlock, the 200 gr. Hornady SP Interlock, the Barnes 180 gr. TTSX, and the Nosler 200 gr. Accubond bullet. Both Hornady bullets have a relatively short spire point, whereas the Barnes and Nosler bullets have much longer, more streamlined noses. The Barnes bullet is all copper (less dense than lead) and is much longer that the Hornady bullet of the same weight. The Nosler bullet is of conventional lead core design, but includes a very long pointed nose and a boat tail. Hence, it is much longer than the Hornady bullet of the same weight. The chamber reamer dimensions selected result in a design that can pretty well accommodate nearly any jacketed .358 rifle bullet of 180 to 200 grains from any major manufacturer. You would, of course, need to experiment to see what the optimum overall length of the loaded cartridge is.

You could use somewhat heavier bullets than 200 grains. However, you begin to face a tradeoff situation in that the bullet base must be seated so deeply that it may significantly intrude on available powder space. Heavier bullets may also warrant a slower burning powder. I chose not to go that route, believing that available bullets weighing 180 to 200 grains would do just fine for whatever big game animals I would likely hunt, including deer and elk. I especially like the Barnes TTSX bullets and the Nosler Accubond bullets for elk.