That would make for a potent subsonic round.

 

FYI, Winchester has introduced another straight wall cartridge, the .450 Legend, suited for AR-15s and other action types. It headspaces on the case mouth. Rim diameter is .422", same as our 6.8 SPC, thus rifles chambered for it will have bolts suited for replacement barrels chambered in 6.8 SPC. Same goes shell holders. So, if you always wanted a bolt action 6.8, the gun world just became a little more accommodating.

The .450 Legend is interesting in its own right, see the SAAMI chart below. While the case rim is .422", it is rebated behind a .440" case head. Note the gradual taper to .427" at the case mouth, the very short .4015" diameter by .010" long throat, behind a 1 degree-30 minute leade down to the barrel's .390" bore. I guess as long as you keep your brass trimmed to just the right length, headspace should not be a problem. Personally, I prefer cartridges that headspace on rims, belts or shoulders, no matter how skimpy. - CW

https://saami.org/wp-content/uploads/2023/01/Public-Introduction-400-Legend-2023-01-30.pdf

 

FYI, Winchester has introduced another straight wall cartridge, the .450 Legend, suited for AR-15s and other action types. It headspaces on the case mouth. Rim diameter is .422", same as our 6.8 SPC, thus rifles chambered for it will have bolts suited for replacement barrels chambered in 6.8 SPC. Same goes shell holders. So, if you always wanted a bolt action 6.8, the gun world just became a little more accommodating.

The .450 Legend is interesting in its own right, see the SAAMI chart below. While the case rim is .422", it is rebated behind a .440" case head. Note the gradual taper to .427" at the case mouth, the very short .4015" diameter by .010" long throat, behind a 1 degree-30 minute leade down to the barrel's .390" bore. I guess as long as you keep your brass trimmed to just the right length, headspace should not be a problem. Personally, I prefer cartridges that headspace on rims, belts or shoulders, no matter how skimpy. - CW

https://saami.org/wp-content/uploads/2023/01/Public-Introduction-400-Legend-2023-01-30.pdf

Those drawings say 400 legend are there two new cartridges? 400 and 450?

 

Saw a video on YT (Ron Spomer Outdoors) reviewing the new 400 Legend. He mentioned that it is based off the 6.8 SPC. Is this going to have a positive or negative effect on 6.8 brass availability? Thoughts?

I'm asking because when the 300BLK came out, 221 Fireball brass was unobtanium for some time after.

 

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.

 

From the ballistics I saw, it's a 215gr bullet at 2250fps. Unknown barrels length.

 

I hope that boy has evolved beyond knucklehead status concerning the 6.8, compared to when he was first exposed to it. I wanted to give him a swift kick in the rear after reading his nonsense.

 

He seems to like it.

 

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

 

Maybe neck it down to a 6mm?

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

 

Not sure. Since it is a rebated rim, bolt thrust would be calculated on the major diameter of the case.

 

Hopefully Hornady will ramp up the production of 200gr. XTP bullets again as this bullet is an ass kicker in my 10mm!

 

Giantmike: Yes there are two cartridges, the new .400 Legend by Winchester and the rather different shaped .450 Bushmaster introduced several years ago by Hornady. Personally, I prefer the 6.8 SPC over either of those fat little, short range rounds. - CW

 

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

 

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.

 

The 400L uses a 0.422" diameter bolt like the 6.8 SPC, but case is a little larger diameter ( 0.44" vs 0.4207"). It also only runs at 45,000 psi and the case length is 1.65". It IS a member of the 30-30/ .30Rem/69 SPC family, but it is the short chubby uncle that is just a little off.

 

Wondering if one reason Winchester went the 20% lower psi is for less sticky casses? Also, couldn’t they have used a 7.62x39 case for less rebated rim, except it may have had too much bolt thrust?

 

I'm guessing that is why they have the threshold lower. Not sure why that they would go rebated rim vs the x39 case head. The only thing that I can think of is that the x39 case head is really not ideal for the AR platform. But, at 45k psi, I would think that it might be alright. Since the Grendel's max psi is around 52k psi.

 

This cartridge is puzzling. It was shown in bolt guns for the intro video. My guess about the case is to play up its relation to the well known 30-30 and to be absolutely certain that there would be no bolt problems. It depends on how much say the Marketing Department had. The lower pressure probably has something to do with available bullets, too, but it is also possible that it is engineered around some particular rifles with marginal bolt strength. They might even be thinking of some lever actions like the Marlin 336 that could use the rimless 35 Rem.

 

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?

 

There is also the 360 Buckhammer straight wall that is being chambered in Henry lever actions.

 

The case is slightly shorter than a 6.8. For the TAC6 we trim to 1.57ish and then resize (and final trim/chamfer/debur). So I don't see why you couldn't.

I think in one of the oth threads the pressure was listed at 45k or something.

I probably need to merge the threads.

 

Ok @Nincomp @chasw and @BTdriver the 400L threads have been merged and put in the Alternative Caliber subforum.

 

👍

 

Good idea, Greentick. I get confused when the same topic is on several threads. Then again, I am old and easily cofused.😮‍💨

 

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.

 

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.

That'll likely be the best thing for AR15 wildcat tinkerers to come from this 400L introduction.

 

Are cases going to be makeable from the starline 6.8 basic cases?

 

Nope, but they can be (and have been) made from 6.5 and 7.35 Carcano cases.

 

R Spomer and others on youtube are incorrect. The 400L isn't based on the 38-55/30-30/30Rem/10mm/6.8spc/221val case family. The only thing the 400L case shares with those cartridges is the rim diameter.

Rather, this round is based on the 6.5 (and 7.35) Carcano/220Russian/7.62x39/220ppc/5.45x39/9x39/Grendell/ARC case family. Head and body diameters bear this out. The 400L has the rim rebated to .422" from the origional .447" of those cases.

This combination gives a few advantages. The added body taper compared to the 400AR and similar earlier 30Rem/spc/etc based .40 wildcats greatly aids feeding. A 40 cal rifle round based on the 30rem/spc/etc case is basically straight.

The .422" rim of the 400L allows the use of the stronger spc/val bolt in place of a x39 or Grendell AR bolt. As stated earlier, bolt thrust is controlled by case head diameter, rather than rim diameter. The .422" rim diameter just allows more support for the locking lugs at the bolt face. Of course, in a bolt gun or an AR308 based rifle wouldn't benefit from the rebated rim.

I've been pondering a carcano based 1.6" long .400 wildcat with a 30rem/10mm .422" diameter rim for a few years for those very reasons. Never had the time to build it however. Too many other projects. A few folks have used the carcano/Grendell case for .40 cal wildcats already. This is the first I've seen with the .422" rim.

 

Rather, this round is based on the 6.5 (and 7.35) Carcano/220Russian/7.62x39/220ppc/5.45x39/9x39/Grendell/ARC case family. Head and body diameters bear this out. The 400L has the rim rebated to .422" from the origional .447" of those cases.

This combination gives a few advantages. The added body taper compared to the 400AR and similar earlier 30Rem/spc/etc based .40 wildcats greatly aids feeding. A 40 cal rifle round based on the 30rem/spc/etc case is basically straight.

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?

 

Would like to see some wildcats off this just for fun