.358 WSSM
This is a wildcat cartridge that I will be using in a Browning A-Bolt.
Rifle: Browning A-Bolt
Hunter
Forming: Forming .358 WSSM
Cases
Bullet Choices
I kind of prefer lighter, faster bullets because they offer a flatter trajectory. However, the range of bullets that suit this caliber are sparse. I think my ideal loads will be the 180gr Speer Hot-Cor FN and the 225gr Sierra GameKing.
The 180gr Hornady bullet is only good for a maximum velocity of 2400 fps, so I want to avoid that. The 180gr Speer bullet is supposed to be good to 2900+ fps.
The .358 Winchester achieves 2490 fps with a 200gr bullet. The .358 WSSM easily achieves 2550 fps with a 180 grain bullet, and some people exceed 2600 fps at that weight.
| Heavy Game | ||||||||||||
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A cartridge using the 225gr Sierra GameKing is the load for this rifle, because it shoot so accurately. The bullet is designed for .35 Whelen velocities, which I am approaching. It is perhaps excessive for whitetail, perfect for heavier game such as elk and black bear, and it should be great on hog. A real heavy hitter. Also, my rifle really seems to like this bullet.
With N135, I appear to be getting 2600 fps or better. With that velocity, I still have 1500 ft-lbs at 400 yards. |
Sierra 225gr GameKing: I didn't think I wanted to use a bullet this heavy, but my rifle really likes it. Shooting twelve rounds with a 4.4 grain spread of VV-N135, every shot landed within the two inch bull's eye. I could hunt deer with this combination today. It is a well-constructed bullet, intended for velocies such as I am getting. This is definitely the bullet I need to concentrate on.
Speer 180gr FN: The manufacturer says this bullet should perform well at 2900+ fps — which is good, because I will probably be driving it that fast. An inexpensive bullet, but not as accurate in my rifle as the SGK.
Beartooth 200gr FN: Ordered in .359" diameter, this bullet wouldn't chamber – the diameter wouldn't allow it to fit into the throat. Maybe I should check the diameter of the bullet, but I guess I have to find another solution for hog.
Hornady 180gr: The manufacturer claims this bullet is only good for a maximum velocity of 2400 fps. I can't use it for this cartridge.
VV-N135: The Hornady manual puts this powder at 2800 fps with a 180gr bullet using a max charge of 51.9 grains. However, at 47.5 grains, the velocity was almost 100 fps faster than expected. This suggests I might reach 2900 fps with this powder for 180gr bullets. It looks promising for 225 grain bullets, as well.
Data
I have been told that a .358 WSSM case has just 1.7 grains less water capacity than a .358 Winchester. Since the WSSM is standardized at higher pressure than the .358 Winchester, the difference in case capacity is probably a wash. It should be safe for me to use .358 Winchester starting load data and work up.
| sonex184, 180 gr. Hornady, 24" bbl | ||
|---|---|---|
| Powder | Charge | Velocity |
| IMR 4198 | 44.0 | 2630 |
| RL-7 | 44.0 | |
| AA2015 | 50.0 | 2675 |
| H4895 | 48.0 | 2600 |
| VARGET | 51.0 | 2600 |
| N135 | 51.0 | |
| Benchmark | 48.0 | 2640 |
| kludge, 180 gr. Hornady | ||
|---|---|---|
| Powder | Charge | Velocity |
| Benchmark | 45.5 | 2461 |
Slower Powders
There is a discussion that the short, fat shape of the WSSM case leads to faster burning. In that case, a slower burning powder might be advised. I might look at the available data for .358 WSSM and then try the slower powders on the list.