Has anyone delt with this company before?
Does anyone have any balistic data on the .416x39 or the 357 rimless maximum?  How about availability of brass or loaded ammo?

[url]www.ar15barrels.com[/url]


DAMN YOU!  WHY DID YOU HAVE TO POST IT ....... and why did I have to open it!

Now you got me to add something to my want list! [}:D]

Now that I have celibra...err vented... to your questions.  I have never heard of the two rounds you list.  It's possible they are new wildcat rounds.  A search on the web might bring it up.

357 rimless maxiumum....I think they want you to use 357 maximum data.  They say they sell brass..... but fire forming doesn't sound that hard....  (parent case is .223 Rem)

The heaviest load for the 357 Maximum (a revolver) is listed 180gr and max vel is 1550fps.  Out of a T/C it is a 200gr going 1750fps.  (Hornady book)

357 Rimless Maximum specs
[img]http://www.ar15barrels.com/gfx/357rm-bg.gif[/img]
It looks like a simple "wildcat" that uses .357" bullets.

.416x39
[img]http://www.ar15barrels.com/gfx/416x39-bg.gif[/img]
Hard telling what cal this really is.  I'm guessing 44 mag (.429").... could be wrong.

I thought the 416x39 looked like a 7.62x39 blown out straight.  I figured it probably used bullets designed for the 416 Rigby and such.  These both look like an interesting step between standard pistol caliber and the 50 Beowolf and 458 Socom.  I wonder what magazine is used for the 357, and many rounds will fit if a standard 223 magazine is used.
I also recall reading an article about using 357 max brass in a 357 mag revolver loaded with four cylindrical slugs stacked atop one another.  [:D]

Well, if the parent case is a 223.  And all one is doing is straightening the case.. I'm guessing a 20 round mag will still hold at least 18 rounds.  It doesn't give a loaded length though....

I'm going to have to E-mail this outfit for more info.  The wheels are really starting to turn now.  I really like the idea of having an upper that I can use for Pistol Caliber Carbine matches that doesn't use $65 magazines or magblocks and it would enough punch to use on deer.

Looking at the pics, it doesn't show a neck.  But there is a slight neck on the case.... if you look at the numbers.  It sounds like an interesting round.... the 357 Rimless Maximum. Please post any info you find out.

Edit-
That round seems really familear.  I thought I heard of a proposed wildcat that was bascially the same, but a .355" instead.

Ah..found it... 9mm CQB by Teppo Justu (makers of 458 Socom).  [url]http://www.teppojutsu.com[/url]  But the parent case is based on a .30 Remington case.

I sent them an E-mail and will post any interesting info.

Interesting, will have to look at the site and see what they have.  As to the two rounds, I actually have them in my design book, but never pursued them for my own reasons.

Best I can tell, the 357 Max rimless made from 223 brass could be made just as easily from 357 Max brass and turning off the rims.  Fireforming a RIMLESS case without shoulder requires a "special" rig because you don't have the rim or shoulder to hold the case in place.  And you couldn't fireform in an AR without shutting off the gas system, so you are looking at getting their brass. Same goes for the 416x39.  Loaded length for the 357 Max is 1.96" and for the 416x39 using a 350 gr bullet should end up around 2.25" (same as .223)

IMHO, headspacing off the case mouth is not ideal, but it can be done.  I used the 30 Rem case for the 358 CQB (it takes both 9mm (355) and 357 bullets), but found that the shoulder was too small for headspacing.  Performance approached that of the 357 Herrett, which is a decent deer round.  Problem is that they (the 358 CQB) would not work in 223 mags.  This 357 Max Rimless should, EXCEPT, that when you go straightwall, you hit the "hump" in the front end of the mag and then you start bulging.  Even the 338 Spectre does this, and from best I can tell you can't go bigger than 30 cal before running into this.

The 416x39 should be the 7.62x39 blown straight.  The 416 bullets are all quite heavy and as such will eat powder volume, and the round will likely end up performing like a Whisper (R).  Nothing wrong with that, but I would have gone with .411 to have the option to use the JHP pistol bullets along with the heavy rifle bullets.  Again, magazines are the tricky part, the 7.62x39 mags I don't think will work, but they may.  The 223 mags tend not to like the 7.62 based round at all...

The rounds are good rounds, the 357 holds great promise, and I looked at these myself.  Getting them to feed from the magazine will be the greatest challenge.  Typically you will find less than 10 rounds will work, after that the mag starts bulging too much.  For deer, the 357 should work well, and as an alternative to the Whispers, the 416x39 should work just fine.

Now, I do have a box of 44 Mag Rimless sitting on the shelf in the shop, these fit in AK mags, and there is an existing wildcat called the 357/44 Bain and Davis.  If they ever manage to get an affordable AR lower that takes AK mags, we can make some fun rounds with it (or just the 44 Mag Rimless, should be quite the power house)

Marty ter Weeme
Teppo Jutsu LLC

Edited because I sounded like a grumpy old bastard and didn't want to come across like that ;-P and to answer a few of the questions in the other posts.

Thanks again Marty for another enlightening reply.  

Yes, thanks!!!! [:)]

Here is the reply I got from Randall Rausch of ar15barrels.com.                                                                                

Both of these are still under development, but I can give you my
expectations.
357 rimless max, simply look at 357 max load data in any loading manual, and
add 250-400fps to the 10" pistol data.
416x39, I am hoping to see 1200+ fps with 350gr bullets and will probably
load 400's to just stay subsonic.
Magazines capacity is the big question on these two as I am working with
several different AR mags right now to see which ones will feed these
rounds.
So far, it looks like thermolds have the smallest step inside that usually
bears against the 223 shoulder on each side.
That step is the challenge with long straight rounds in AR mags...

357 Rimless max is based on blown out 223 brass.
416x39 on blown out 7.62x39 brass.
I will be selling the 223 brass for $25-$30 per 100, formed and trimmed.
416x39 is going to be $40 per 100
I do not plan to sell loaded ammo.
357 rimless max uses readily available 357mag/max dies, with modifications
to the seater if you want to shoot spire points.
416x39 Dies are going to be available from CH tool and die, prices to be
determined at a later date.

Randall

Because of the step in the magazine, I had to buy thermolds for my .300/.221 Fireball (aka Whisper). I had intended to use GI's and was told they wouldn't work (partsbymurph). Can hardly wait for warm weather and a chance to shoot that rifle for the first time.

Interesting.  Very interesting indeed.  I guess w/ wildcatting the AR, the mag will be the "obstacle".  I shall have to follow the round development....

Provided Randall doesn't object, I would be happy to work up some loads for the .416x39, using some of the more common powders and bullets.

Randall - if you are reading this, drop me a line.  Also, for mags, try the MWG 10-rounders, they are easier to remove the hump, I did it with a Dremel (and a dust mask).

The lighest bullet in 416 is the Barnes 300 X Spitzer, I have no idea if they would work, they may not let you seat them deep enough.  There is the Woodleigh 340 gr, but those are costly.  Speer makes a 350 gr Mag Tip, I think that would be your best bet.  What twist are you going to use?  Needs to be pretty fast to stabilize those heavy puppies ...

MartytW