200 grain bullets at 2600ft/sec

It's the new Wildcat .358/.25 WSSM

Imagine a 200 grain bullet fired out of a standard AR-15 platform at or faster than a Winchester .308 can do the same thing.

Lets put that in perspective:

308 with 200 grain bullet at or under 2600ft/sec
only the 300 Winchester Short Mag is getting 2800ft/sec with 200 grains, but you have to move up to the large heavy AR-10 platform.

now onto other 35 cal's
357 Maximum 1650ft/sec
357 Herrett 2000ft/sec
35 Remington 2050ft/sec
358 Winchester 2550ft/sec

But:
350 Remington Magnum 2700ft/sec
35 Whelen 2700ft/sec ....... finally something that will actually beat the little wonder.

DTech (aka Mike Milli of Dtech Super Store http://www.dtechsuperstore.com/ ) of the WSSM AR platform design fame has the following to say:

http://i88.photobucket.com/albums/k1...prey/358ws.jpg

"Last year I learned that Indiana had changed it's game laws to allow a select group of handgun/rifle cartridges to be used for white tail hunting. Up until 2007, Indiana's white tail hunting was "slugs only", so this news got me thinking. The Winchester Super Short Magnum (WSSM) necked-up to .358 would darn near qualify under this new law.

I have been building conversions for the .243 and .25 WSSM to be used on the AR-15 platform for about 4 years now. They have been wildly popular so I decided to dive into some new wildcat cartridges on the WSSM line, and do one of them to qualify for "Indiana dear legal". I ordered barrels from Shilen, reamers from PT&G and dies from Hornady. It's been a long wait, and everything I have needed for these new projects has arrived.... Except for the dies! Well, just the other day I received a large box from Hornady packed full of dies!

Now the work starts! I took one of the new Shilen stainless steel, match barrels and chambered it in .358/.25 WSSM. I left the barrel full-length and did not contour it, giving me as much flexibility as possible. I had decided to use .243 WSSM brass as it is much more available than the .25 WSSM brass. I chose the sharper shoulder-angle of the .25 WSSM version, so now I have to figure out a way of getting .243 sized necks stretched out to .358! I annealed a batch of about 25 cases and tried fire-forming the cases with a fast-burning pistol powder and a filler of "cream of wheat". I took a stab at the charge and tried on. It worked perfectly!

I soon had 25 fire-formed cases, and decided to try doing some load-development. I wasn't after accuracy at this point, I just wanted to get some base-line velocities and start the barrel break-in. I selected AA-2015, and decided on a safe starting point. The first shot made it quite clear that my starting point was on the safe side. I increased the powder charge and watched the velocity climb. By the time it was time to go home for dinner, I had a little over a dozen rounds down the tube and the velocity on a 200 grain slug was a little over 2650 FPS. Even at this point, there were no signs of high-pressure. I am anxious to get back to it in the morning and see what kind of velocity I can get out of this thing!

Here is a picture of my cases. Prior to fire-forming, after fire-forming and a loaded round. Due to the fact that I am dealing with a semi-auto, I decided to figure out a way of "capping" the cream of wheat so it wouldn't spill in the chamber. I took a Styrofoam cup and used the mouth of the case to cut "plugs" out of the cup. In the unfired cases, you can see the Styrofoam "plugs" in the case-necks. "

Quote Copied from:
http://www.oa2.org/forums/viewtopic....864&highlight=

PS. He is also working of a .338 version.