Just was watching the GA tv show and they were talking about Marlin's new cartidge, the 338 ME.

ANybody know about his one? A 200 gr bullet @ 2600fps.

Can't find it yet on Hornady's website.

i guess if they necked down the 450 marlin case they might be able to obtain that knid of fps hope it is true. i have used a 255gr .452 bullet patched with teflon tape and got it going 2600 fps out of marlin cowboy. i have read data of 275gr going 2800 fps out of 1895 cowboy, but that is not what i would think of as a safe load.

Those are pretty good ballistics out of a levergun. If it is a necked down .450 case then you would only be able to get around 5 rounds in the tube, I hope it's smaller than that.

They said what case they used but I forgot what, it wasn't the .450. They only showed the XLR model, which I kinda like but would want the more traditional look if I was to get one. Pretty good idea for our Colorado Elk and the big Mulies.

It's based on a shortened 376 steyr case with a rim . So base diameter is close to a 45-70. Hornady designed the 376 case.

6PT,
As I wrote in the other post I like all lever-action cartridges. Hornady/Marlin has apparently tried to duplicate the .356 Winchester in a package which allowed the LeveRevolution bullet to work through the Marlin action. This required a larger diameter case.
I did a little speculating on the .376 Steyr case and came up with the dimensions in the picture. I hope Greg mushial will forgive me for posting a picture from his RCBS Load program.
I shortened the case to the same overall length as the .308 Marlin Express and put the shoulder in the same place as the .308 ME.
So, my case capacity estimates on the .338 Federal are:
Total case capacity: 60.5 grains of water
With bullet seated .360”: 50.3 grains of water
With the dimensions shown in the drawing I estimate the powder capacity of the .338 federal as follows:
42.9 gr of Hodgdon 4198
44.3 gr of Hodgdon 4895
42.8 gr of IMR 4064
44.4 gr of Alliant RL 15
Not load data of course just speculation on capacity.
This compares very favorably with the .356 Winchester. The .356 Winchester has a total water capacity of 59.8 grains of water. With a bullet seated .358” the water capacity is 50.7 grains.
I estimate the powder capacity of the .356 Winchester with the bullet seated .358” as follows:
43.2 gr of Hodgdon 4198
44.7 gr of Hodgdon 4895
43.2 gr of IMR 4064
44.7 gr of Alliant RL 15
So there is not a lot of difference between the potential performance of the .338 federal and the .356 Winchester – using equal barrel lengths. 24” barrel data for the .356 Winchester using a 200-grain bullet is the same as the preliminary data we have for the .338 Federal.
This should make a fine cartridge for lever-action hunters.

]Edit i forgot to mention I added the rim to the cartridge case so it matched the .308ME] Edit

Since I've started checking into the info the last couple of days, it is my understanding that Marlin/Hornady wanted to duplicate 33 Winchester performance with the advantage of a "pointy" bullets, a rimless case, and a cartridge profile that wouldn't allow other, similar cartridges to be chambered in the action. So they wanted something delivering a 200-grain bullet at 2200 FPS plus.

Of course I'm interested but us cast bullets guys need to petition Hornady to reintroduce the 338 gas checks (#7090). I went ahead and purchased 2K of them as I figure I can sell them on eBay if necessary and they won't get any cheaper. As soon as I see the chamber drawings, I'm going to get a jump on this project and get a bullet in the works!

There is a reference to the 338 Marlin Express on his recoil table. I don't know where he gets his data, but it shows a 200 grain bullet having a muzzle velocity of 2400 fps. Compared to a 338 Federal, which has a 210 grain bullet with a velocity of 2630 fps. I suspect there will be a significant difference in maximum pressure. The 338 Federal is loaded to 62,000 PSI. Cartridges intended for lever actions tend to be much lower (for example, the 450 Marlin is standardized at 43,500 PSI).