[earlytom]

He seems to like it.

 

[earlytom]

Test barrel is 20 inches. At the bottom under chart.

 

[earlytom]

Maybe neck it down to a 6mm?

Should be able to go with 55K of pressure like a 6.8, no?

 

[earlytom]

I am intrigued by the 400L case. More capacity and stronger bolts. I'm thinking 6mm is a good candidate.

 

[earlytom]

it will depend on popularity. In essence its turning 6.8 brass into a .40/10mm straight wall cartridge. All 3 cartridges come from .30 Remington brass. I tried once to cut the shoulder of 6.8 brass to make 10mm brass, but the wall is thicker. You would need to ream it out slightly to seat a bullet.

Nativeman I think the 400L is a new case. It’s a rebated case with the SPC bolt head size of .422 so it has more capacity from the larger body size. That’s why I am thinking it might be possible to neck it down to a 6mm. We might get to 6 ARC capacity with a stronger bolt and higher pressure. H would be the guy to say if such a cat would work.

 

[earlytom]

I'm intrigued by the idea as well. But, I'd have some concerns with the rebated rim. I know some calibers, such as the .22 Nosler, struggle with extraction in the AR platform due to having a rebated rim. Obviously Winchester must have got it figured out for the 400L. But, the 400L is essentially a straight walled cartridge, so I'm guessing because it doesn't have a shoulder, extraction is easier. But, by necking it down and introducing a shoulder, a 6mm wildcat might pose some problems for extraction with the rebated rim.

Valid concern. Though the 22 N is rebated down to a 223. Thinking the SPC bolt would work.

 

[earlytom]

Well it seems it may be close for forming a 6mm cat. The once or twice fired case might be 1.67, and the TAC 6 is 1.57, while the ARC 6 is 1.47.

What shoulder angle? Just curious would it still feed at say 1.37? How short would it actually be after forming? How much bolt thrust would be reasonable? Max pressure?

 

[earlytom]

I'm thinking it's probably available bullets is the reason for the low pressure spec.

I hope it could be done. Probably be a PITA. Have to be in stages I'd guess. It's beyond my knowledge or skill currently, but I sure like the idea of a ARC capacity cartridge able to take SPC pressure and maybe squeeze more speed from it than the ARC.

 

[earlytom]

The base of the case is only 1 thousandth of an inch smaller than the Grendel/ARC case, so that is possible. The odd thing is the 45,000 psi max pressure vs the 52,0000 for the Grendel/ARC. It makes me wonder if there were bullet issues or if the pressure was held down for a particular rifle design. Possibly a lever action?

IMO likely for lever action. Should be GTG at useful bottleneck pressures.

 

[earlytom]

I know it, sure seems like it. Haven't seen any ammo yet.. Anybody seen 400 Legend anything? Rifles,ammo, dies?

 

[earlytom]

Savage announced rifles in May, still nothing. So yeah it seems DOA. Too bad really, I was looking forward to maybe getting one.

 

[earlytom]

I see that ammo is available from numerous sources, so I haven't given up hope yet.

Even got a 20% rebate till the end of the month.

Winchester Power Point 400 Legend 215gr Soft Point 2250 FPS 2416 FT/Lb 20/box

Winchester Power Point 400 Legend 215gr Soft Point 2250 FPS 2416 FT/Lb 20/box In Stock!

www.aeammo.com

 

[earlytom]

Here's what a Savage is supposed to look like. They don't have one 400 Legend on their web site. I can't find one in the wild.

 

[earlytom]

Its case only slightly shorter than the 6.8 SPC, 1.65 inches vs 1.687 so it could possibly make a good candidate for another 6mm wildcat, or will it be a smidge to short?

 

[earlytom]

Does the world need another 6mm wildcat???

A 6mm for the AR, isn't a barrel burner, uses the 6.6 bolt and lobs 105s and 108s? Yep. Especially since the TAC6 is kaput... Well yeah.