We need a 40 GNR

Sunday, September 18, 2022, 01:05 (18 days ago)

Many jurisdictions only allow straight-wall centerfire cartridges during rifle season. And many of those have a 1.80" case-length maximum.

Such a cartridge based on the ubiquitous 30-30 family of brass makes good sense as the cheapest, most readily available rimmed brass. Both the 400 GNR and the 375 Win are straight-wall cartridges in the 30-30 family, but both exceed the 1.80" case limitation. Hence, I think we need a shorter version of the 400 GNR, call it the 40 GNR.

I'd propose one of the following case lengths for the 40 GNR:

1.29" - to match the common magnum pistol cartridges
1.383" - to match 454 Casull
1.61" - matching 357 maximum and the supermagnums
1.80" - maxing out the 1.80" allowance

A 1.29" case length would allow chambering in most any common revolver, though it's pretty close to being a 401 power mag.

A 1.383" case length can offer something unique to the market, and if cut-down 375 Win brass is used, something approaching Casull pressures can be used. Would be too long to chamber in Smiths, but Blackhawks and Redhawks would work fine.

A 1.61" case could still be chambered in stretch framed revolvers, while approaching carbine power-levels

A 1.80" case obviously maxes out the limit. I'd expect this to cycle best in any lever actions previously chambered for 400 GNR, though much to long to chamber in any revolver.

Or you could use the 460S&W case

Sunday, September 18, 2022, 04:09 (18 days ago) @ Keith

And straight wall neck it down to .429 have a great selection of bullets!

No problem. All it takes is 12 to 14 months and $2000

Gary Reeder
Sunday, September 18, 2022, 14:42 (18 days ago) @ Blake

piece of cake. A straight case in 40 caliber already exists. It is the 10mm Magnum, but not extremely powerful. At 1.24 brass and 1.54 total length, you are still almost identical in size and length to the 41 Magnum but still less power. The ancient 401 Power Mag was a 40 caliber but less power than the 41 Magnum, which is why it died on the vine. And the thought below of making it straight wall but neck it down to .429. You can't have a straight wall and neck it down too. One or the other. And if you want something in .429, you already have it in the 445 Super Mag. And if you want something less length than the 30-30 case but with the power of the 454, it sure won't be a 40 caliber.

The simplest and cheapest way to go is the 445 Super Mag.

Gary Reeder
Sunday, September 18, 2022, 14:53 (18 days ago) @ Gary Reeder

No straight wall case in 40 caliber will handle 454 Casull pressures. Even hot 30-30 loads will bulge the case and those pressures are way below the 70K pressure level the 454 hits.

The whole spirit of these laws are to open

Monday, September 19, 2022, 06:34 (17 days ago) @ Gary Reeder

more hunting opportunities in areas where long range calibers are a concern. They get overrun with does and need some extra harvested. The straight wall case rules add some interest, lots of old rounds including all the pistol/carbine rounds that do well. Even the .357 Mag. in a carbine with 170-180 gr. loads is a good round for small deer.

Doug found some hunting available on base but it was shotgun only, then they added the "straight wall" cartridge rule. Makes it more interesting. Blinding power is not really needed.

30-30 more common 445, 375 Win close enough to 454 brass

Monday, September 19, 2022, 10:08 (17 days ago) @ Gary Reeder

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Something larger than .30-30 would be better

Sunday, September 18, 2022, 06:13 (18 days ago) @ Keith

just a smidge. The ancient .401 Winchester is right there and while 0.406" bullets are spec. I usually just load cast .410". I think the case length is about right. A case is needed that would allow some taper for reamer production and extraction.

I use blown out straight 7.62x39 brass for making .401 Win. Starline .414 SM brass can me modded to perfectly replicate .401 Win.

If you HAD to have a .400" bullet these cases would work just as well a few thousandths necked. I think the spec is 1.6" so that is plenty within the requirements.

The 30-30/375 Win case is the point

Monday, September 19, 2022, 10:02 (17 days ago) @ WB

There's lot's of ways to go about this, but the point is something that can be done easily/conveniently/cheaply. There's not much more readily available than 30-30 brass.

The x39 route is interesting, but no rim.

The .414 SM is not what one might call "readily available," and necking isn't an option. Perhaps you meant "tapering."

Yes .414 would be a unperceivable taper

Tuesday, September 20, 2022, 07:39 (16 days ago) @ Keith

to a .400" bullet. The .30-30 gets thicker a bit as it gets shorter. Of course inside neck reaming will fix about anything. But your "easy" goes away.

I discussed the .400 GNR chamber dimensions after he built it for Gary and there were some machining and extraction limitations that went into the final design. A literal "straight wall" chamber can cause problems so most designers have at least a couple thousandths taper. The .30-30 is only so big at the rear web so that is one limit, then at the other end you have a .400" bullet plus the case wall thickness X 2 sides for the required chamber mouth. Then the lead into the rifling. There is more to it than what most think. That is why it cost so much in money and TIME. You have to have roughers and finishers not to mention dies.

I'll get back to tinkering and see what a .30-30 cut off at 1.75" looks like. The .400 GNR should shoot it and you can even load it with 10mm or .40 S&W dies, if you are good.

I started to get into this "conversation" but

Gary Reeder
Tuesday, September 20, 2022, 13:33 (16 days ago) @ WB

thought better of it. My suggestion was keep it simple and go with a 445 Super Mag. My problem was those trying to get 454 Casull power out of a 30-30 cut down and chambered in 40 caliber. It ain't gonna happen. The 30-30 case is a good one but not as strong as some other common caliber brass. It wasn't meant to be as hunters a hundred years ago didn't need 454 power to kill a deer or black bear. To keep your brass to 1.6 keeps your powder capacity to a somewhat minimum.
Years ago Kase and I hunted a lot with our 30 Herretts which is a 30-30 case cut to 1.6". I tried to boost the power of the 30 Herrett up trying to hit the 2500 FPS mark and just ended up splitting the neck and shoulder of the case plus my accuracy went downhill. The 30 Herrett was a 125 grain bullet at 2200 fps. I hate to list energy as it is a mythical figure. Energy does not exist, period. That is why so many folks go by John Pondoro Taylor's TKO figures. It is much more realistic than energy figures as energy is solely dependent upon speed.
Anyway the 30 Herrett has 1300 FPE (energy) The 454 Casull is a 240 grain bullet at 1900 with 1955 FPE (energy). But anyone that has shot a 454 knows there is a helluva lot of difference in the two. Kase at 10 years old could handle the 30 Herrett with no problem at all, but I would never have given him a 454. My rambling here is mainly to get the point across that you are not going to get 454 Casull power out of a cut down 30-30 case chambered to 40 caliber.

I don't think the goal is to get 454 performance

Tuesday, September 20, 2022, 14:20 (16 days ago) @ Gary Reeder

Though, for anyone who wants to get closer, starting with thicker, stronger 375 Win or 225 Win brass would help contain higher PSI than 30-30 brass could withstand, though still not to the level of 454 pressure (or powder capacity).

The real purpose is exploring other uses for 30-30 brass blown straight: first, shortening 400 GNR to fit within the 1.80" case-length limitation, second, going further to 1.61" case length to fit within the cylinder of a stretch frame, and third, going to 1.383" or 1.29" case length to fit within the cylinder of a conventional revolver.

True. As much as I love the odd .400 there

Wednesday, September 21, 2022, 14:23 (15 days ago) @ Gary Reeder

are a lot of negatives, mostly the components. But I enjoy the challenge of making them myself. For most folks the .400 at any power level beyond 10mm auto will be a challenge and less likely to be economically viable.

Actually, and I don't like the taste of this, I'm a .44 guy at heart. But the .460 S&W is likely the hands down winner for the straight walled "hunting law" cartridge. The .460 will cheerfully shoot .45 Schofield, .45 Colt, .454 Casull, and .460 S&W. Or anywhere you choose to cut it in-between. So you can go from mild to beast mode at whim.

I have serious reservations of shooting a .454 Casull, would rather face a .475 Linebaugh! The fear of that hammer spearing my hand web, the front sight dinking my forefront, and that knuckle searing guard rap, palm numbing to the elbow. I can back off and enjoy it a lot more and still kill anything shy of a T-rex.

I've the same feelings about the 454

AmBraCol ⌂, The Center Of God's Grace
Saturday, September 24, 2022, 15:16 (12 days ago) @ WB

The first 475 Linebaugh I ever shot was built by some guy named Gary Reeder. It was a Ruger Bisley he built for a friend of mine up in Oregon. We were out at a mutual friend's place, shooting on a private improvised range. I was offered the opportunity to shoot the 475 with some Hornady ammo. I do not recall WHY, but I was shooting over the chronograph they had set up, probably because that's where there was a bench lined up with a target. Anyway, I was prepared for "the heavens to part and the elements to melt" but thought "That wasn't so bad." Then we got a look at the chronograph - IIRC it was 2 or 3 hundred FPS over what was claimed on the factory box. Turns out that ammo wasn't very heat resistant and had been sitting in the sun.

A few years later I was visiting some yahoo named Jim Taylor and casually mentioned I'd never had a chance to shoot a 454 Cassul. So he "kindly" dug out his 454 and a box of Corbon 360 grain ammo and sent me out into the cold to "giver her a whirl". My sons went along to watch. Again I held on for dear life, but each shot brought home the fact that I do NOT care for snappy recoil! The pistol was returned to the owner along with 15 rounds and five empty cartridges in the ammo box. I'll take that hot ammo in a 475 any day over a 454 and heavy loads. I'm still amazed Jim stayed inside beside the fire instead of going out to watch "the fun".

I'm a peaceful man and prefer the pursuit of peaceful sports. Those involving teams and balls of any sort tend to be deleterious to one's body and promote violence by both spectators and participants.

.40-50 Sharps Straight is 1.875 inches

Monday, September 19, 2022, 02:57 (17 days ago) @ Keith

You could shorten it to 1.8 and go from there

400 GNR in an encore, cut case to 1.8" then load, no problem

Sean Harper
Monday, September 19, 2022, 09:40 (17 days ago) @ Keith

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You would have to work up new loads but I am

Sean Harper
Monday, September 19, 2022, 09:50 (17 days ago) @ Sean Harper

sure it would work good


The Starline .38-55 Win. brass, if you can find them

Monday, September 19, 2022, 11:07 (17 days ago) @ Sean Harper

are more thin than typical .30-30 and should help with the thickening brass as it is shortened. I have struggled a bit with .30-30 brass thickness and bullet diameters for the chamber dimensions. The .400 bore is about as far as you want to go on the .30-30.

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