7mm-357max or a 7mm-445 Supper mag

[handcanon]

dose anybody know of shells like 7mm-357max or a 7mm-445 Supper mag. I think the cases would hold about the right amount of powder for a 10" Contender, and them being rimed would be better in the Contender

[HHI 812]

would prefer the .357 Max case, because you can "safely" get the pressures up to rifle like pressures. With the .445 case, you have to really watch your pressures. I guess a lot has to do with which bullet you are going to use, and usually a bigger case is preferable over the smaller case for heavier bullets, but since you also stated a 10" barrel, that is another reason why I would choose the .357 Max case. I wouldn't want all that capacity in such a short barrel. The .300 Whisper has been one of my most favorite cartridges, and it uses the even smaller .221 FB brass, although I had my barrel modified to also use the .357 mag, 360 DW and .357 Max rimmed brass.

[Graycg]

I'm with HHI 812 for all his reasons on the Max over 445 and an additional one...forming to 7mm with the stiff 445 brass that I've seen would be a mo'fo'.....  I'd stick to the Max.

regards,
 Graycg

[Nobade]

Yep, on the max case it's the 7mm supermag. Kind of like a rimmed, short necked 7 TC-U. I've seen a .30 on the .445 case, used in an Encore. It was quite a blaster, but like the others I'd shy away from it in a Contender since you couldn't really lean on it and wouldn't do anything a 30-30 or 30-30 AI could do anyway.

[Joe Kool]

I made up a 7mm wildcat based on the .375 Winchester case. The neck is .250" long, 40 deg. shoulder, minimum body taper. In a 21" carbine barrel I get 2650 fps. with a 140 gr bullet. I haven't tried in a 10" or 14" barrel yet.  

[HHI 812]

because he wanted better case life with an improved case, yet using the same 7x30 brass. The .375 is a stronger case, but gives up some case capacity with the thicker brass.

[Steve P]

I have the 7 super mag in 10" contender.  I use RP 357 max cases, but have even better luck with 5.6X50R RWS brass.  Takes a lot of work to get it ready, but better than the max brass.  If you want to have a little faster yet, use the 5.6X50R brass full length.  Chamber the barrel really deep with 7TCU reamer, and use 7TCU dies.  Mike Bellm even chambers this if you want him to do it.

Have fun.

Steve :wink:

[handcanon]

cool Steve what kind of accuracy do you get and is it better than the 7tcu in the 10"

[HHI 812]

Bellm and getting 2500+fps with a 120 Speer SP. Need to try other powders, and possibly the Nosler BT 120, and from what more powder capacity I have, I'm sure I can get more. But even at 2500+fps, I am getting 1MOA with some loads. Just got the barrel, so need to work out some accuracy loads still. The RWS brass is very strong brass, and haven't lost any brass yet, other than me rushing and opening some cases. I also had a 7x50R Bellm, but didn' really work out any loads, because I sold it preferring to keep the 6.5, since I had more components for it. I also opened some cases to .30 cal, .338 cal and the .357, and can only imagine what ballistics I can get on top of the .357 Maximun I had.

[wheelgun]

I have had a 7mm supermag for a few years.It is about the same as a 7mm tcu i think but it has a very short neck to work with.I like it but the only reason i bought was the price $90.00 and a extra $20.00 for dies and he threw in 60 pieces of formed brass.

[handcanon]

I have also seen that the 7mm Bellm is a 444 Marlin ran thru a 7-08 dies so I don't see why you couldn't do it with a 445 super mag.

[Steve P]

Using the RP max brass, loads and accuracy are very similar to the TCU.  Using the 5.6X50R brass, SD are lower and accuracy is a little better.  Does 1" compared to .75" make that much of a difference thou?

Steve

[handcanon]

Steve
yes that does sound better if you are talking about 100yards.