I've got a couple more of the .358 WSSM uppers to test and ship, so I figured I better get some brass ready. When I built the first .358, I simply used the upper to fire-form the brass. It made a bit of mess in the bore, so this time I decided to do it differently.

The barrel-blanks I get from Shilen are 28" long, so whatever is not used on the barrel that I am producing gets cut off. I took one of the cut-off barrel ends from one of the uppers I was building and chambered, threaded, installed a barrel-extension and headspaced it. It was VERY loud, but much easier to work with, and clean!

Here is a picture of the annealed brass before and after fire-forming, along with my little "SBR" fixture for fire-forming. I'm using a small charge of fast-burning pistol powder, then filling the case with cream-of-wheat. I am putting a plug of Styrofoam in the case-mouth to keep the cream-of-wheat from spilling out before I get it fired.



I'll try and post some pictures of the finished uppers.... Before I ship them out!

Looks like you have that figured out Mike. Nice post...Thanks. Jere'

Very interesting & great idea to fireform.

The large-bore AR-15 chamberings have never "done it" for me, but this .358 happens to be "deer legal" in Indiana. Indiana changed from "slugs only" to allowing some short center-fire rounds, with a minimum bore diameter of .357.

I have been getting quite a bit of orders from Indiana hunters, and even from other states for hogs and bear.

In the "old days" I used to chamber the AR-10 in .358 Winchester. It is simply a .308 Winchester necked-up to .358. This new wildcat based off of the .25 WSSM case necked-up to .358 exceeds the velocity of the .358 Winchester by about 200 FPS! I haven't had time to do much for load development, but have been getting 2700 FPS out of 200 grain bullets. The very first upper I built was a light-weight. The entire rifle, less optics, weighed a little over 6 pounds. I did a some shooting before drilling the gas-port. Wow, without the weight of the heavy bolt moving, that light gun pounded the daylights out of me! My shoulder was black and blue for a week!

How does the .358 WSSM compare to the 450 Bushmaster?

I've never done any load development, or any other work for that matter, with the 450 Bushmaster. All I can rely on is published data.

The published data for the 250 grain factory load in the 450 Bushmaster is 2200 FPS. That would yield roughly 2686 F/lb of energy. The 358 WSSM sending the 200 grain bullet at 2700 FPS has a muzzle energy of roughly 3237 F/lb of energy. Without spending any real time with the 225 grain bullet out of the WSSM, it looks like I would be getting about 3376 F/lb of energy.

Pressure is the big difference. The bolt used with the .450 Bushmaster just can't take the pressures that the WSSM bolt can take.

Significant differences anyway. Keep in mind that the bullets fired from the WSSM would have a higher BC as well.

There will probably be a .450 or .500 WSSM wildcat making it's way to market in the future. I'll keep you posted!

Then my guess would be that the barrels on the WSSM would need to be changed much sooner than the 450 bushies. I think the .358 is a great concept and will catch on.

hmmm interesting

I would not like to meet the man that shot out either the .358 WSSM or the 450 Bushmaster in a dark alley! Barrel life shouldn't be an issue. The .358 WSSM is not something that you are going to go to the gravel-pit and torch off 500 rounds in a few hours. It just has a completely different intended purpose and use than say a .223 or 9mm upper.

Wow that is an interesting case but let me get this straight-it gets 200fps more than a .358 with 200g bullets? What is the capacity of the case? How much powder can you get behind a 220g bullet? And what sort of magazine does it require? TnTnTn

We dont anneal our brass.
My buddy has brass that ha ovr 10 fireings on them.
Of course we are not using that junk win brass either. Some loads that are up to 52.0 grains of powder.
But most are around 50 gr of powder.
Amazing cartridge.
And yes 200 FPS faster then a 358 wichester.

The only two headstamps I have ever seen are Winchester and Federal. Both were actually made by Winchester. I am using the Federal brass for all of my wildcats, but have tried both. The Federal brass had been about half the price of the Winchester, so I laid in several thousand rounds when it was still readily available.

I was shooting some 220 grain bullets this evening...... I think I'm starting to feel it too!

Federal made the Federal brass.
And quilty of the winchester stuff isnt even close to federal brass.
I know where you bought te federal brass and there website is wrong.
This came straight from te Federal boys.

With all due respect, you are wrong sir. I know folks from Winchester, Federal and the place where I purchased the brass. Their statements are all the same: Winchester made the stuff for Federal, to Federal specs.

I just spoke with one of the "Wheels" from Federal today at the gun show, and he was well aware of who made the WSSM brass that is stamped "Federal". I asked him if there was still more of it around, and he told me that they had gotten rid of all of it.

The folks from Federal told me that Federal has always had problems producing extreme bottle-necked cases, and has often had Winchester produce that style of brass for them. The WSSM brass is one of them. When I got my first batch of 5000, they were still in Winchester packaging, with lot numbers and a Federal PO#.

If only the supplier told me this, I would have questioned it too. This has been proven to me MANY different ways.

I'm not going to get into a wizzing match with you on this, and I'm not going to go to the CEO of Winchester and Federal for a noterized statment to prove it to you. Either the folks from Winchester, Federal and the distributor all lied, falsified documents, and created a cover-up that makes Kennedy's assassination look like a slam-dunk, or Winchester simply produced the brass for Federal, like they have many times in the past.

If you don't think it's fact, that's fine too......

So what our telling me is there is no differance between fed and win brass?
Other then the head stamp of course!

Sounded clear enough to me what he said, and that was simply the in the case of the WSSM cartidges, Winchester makes it to Federal specs.

My guy at Federal backs his play as well.

About time someone figured out a (legitimate) use for Cream-of-Wheat.

Have you trid a .338 WSSM Mike? What kind of performance as opposed to a .338 WSM?

No, I have never said that there was no difference between the two, only that they were both made by Winchester. Like Barry noted, I made it pretty clear that it was made to Federal specs.

I actually like the Federal brass better than the Winchester brass, but have used both. I was using the Winchester first because I was actually working on the WSSM uppers before you could purchase brass from either Winchester or Federal. I was getting once fired brass from a guy from Winchester, and the dies that both Olympic Arms and I used in the early days came from a contact of mine at Redding. The Federal brass showed up late in the game by comparison.

Federal Cartridge is "right in my backyard" here in Minnesota, and has often been a great resource to me.

Leon, I have produced a couple of .338 WSSM's, but have not shot them over a chronograph. I used .338 Federal load data as a base-line, and loaded enough for feed/function tests, but didn't take them to the range. The rest of the wildcats on both sides of the .338 has exceeded it's short-action counterpart by 150-200 FPS, and I don't think there is any reason to think the .338 will as well.

Dtech can you post pics of the wssm lineup as far as cartridges go?

Geezzzzz Mike. Please Stop coming up with ways to separate me and my Money!!!!! You're Killing Me!