I have built one 30-30 1.5"on a cadet and it was very pleasant to shoot and quite accurate. Never tried to get that much velocity but used 4759 and about 1400 fps.
The cases are very heavy and     extraction was very easy. At one time I think in Precision Shooting Meryl Martin had a few articles about his use of the short 30-30.
Cheers,
fallingblock

Something like .30 Herrett?  30-20 would be a little small for 1600 fps, even when breechseating.

I don't know what a 30 Wesson looks like so it could be. The reason I chose the  maximum case is because of the  small 3/4 inch barrel shank diameter and wanted more barrel wall thickness around the case than would be provided by a 30-30 hull.
  I have heard of these chambered in 32-40 but I feel that is really to big a case for this action size to be safe and practical. Just my opinion. 
   I made a sizing die from the chamber reamer as well. Being that the whole case is on a taper except for the neck I just kept trimming the base of the die off until the case could be run into it far enough to full length resized properly.  Works really well and have not lost a case yet. I'll need to get out the chronograph to see for sure how fast it is really going but it sure makes a healthy crack with either load. MD

Paul,

Most of these rounds would be too big at the base for the little cadet for comfort - and the cadet would prefer a rimmed round too...

Some additions, but first two caveats: I've built a few Cadets over the years but am still learning 'cause there's a lot there to learn; and I personally have a long & checkered history of pushing the envelope with mechanical things including single shots.

Now down to opinions. First, IMO the Cadet is perfectly safe with any load in a 30-30 or 30-40 or 303 case head size IF and only IF the pressures are kept below 40K psi. Naturally the larger size will cause the barrel tenon to swell at a lower pressure, but 40K psi has proven perfectly safe with the 44 Magnum (0.457") in many, many custom Cadets of my acquaintance. BTW the 44-40 case is both noticeably larger in diameter and also much weaker than the 44 Magnum case and IMO shouldn't be loaded beyond ~30K psi in a Cadet.

Second, any load above 40K psi in any size case will require that the firing pin nose be bushed to a much smaller diameter, preferably under 1/16", and smaller is better. Cases with SR primers appear to be worse offenders in this area than cases with LR primers. The problem is due to the primer cratering & thereby making the primary extraction very difficult, effectively jamming the rifle. The knee-jerk reaction of most folks would be to install a stronger mainspring but this is not the optimum solution and can cause safety issues; much better IMO to bush the block.

For reference, I own Cadets in 219 Improved Zipper and 224 R-C Maxi; my friend George the Knifemaker owns Cadets in 44 Magnum (2), 357 Herrett, 30-30, 30 Herrett, 25-35 Ackley Improved, 218 Mashburn Bee and several more. The above opinions are a distillation of both our experiences with Cadets over the years along with some other folks' reports. Just remember that these opinions are worth every penny of what they cost ya, and draw your own conclusions.
Good luck, Joe

Nice to have input from someone that has first-hand experience with 'pushing things around a bit'.

Also, it's nice to see some real-life examples of pressure - 40k plus - for the Cadet action.

I have just a question or two, and let me restate that I'm neither arguing nor am I trying to convince anyone of anything. I just like to be clear on specifics when the mode of communication is written.

Actual case dimensions for a .44 Mag and .44-40 WCF cases I have in hand are: 0.457" and 0.514" for the head and rim for the .44 Mag, and 0.453"and 0.505" for the .44-40 WCF. In that light, I'm not following
Quote:

Could you clear that up for me please?

Also, regarding strength, you'll get no argument from me that the 44 Mag case is stronger than the older .44-40 cases, but I'm not sure that's the situation with newer manufactured cases, but it certainly might be. Nonetheless, it's moot as the the .30/.44-40 case can theoretically drive a .30 caliber 180-grain bullet at 1600 f/s while keeping chamber pressures below 25k. In fact, most likely well below 25k. So keeping a .30/.44-40 case "below 30k" is easy while retaining the 1600 f/s critereon. As a side note, I drive the .44-40 cases I use in the aforementioned Collath to well over 30k, and have no problems.

Quote:
Really? I'm surprised. With respect to the .357 Max case, I can't get that case (paper-whipping here, not real-life tests), to drive a .30 caliber 180 to 1600 f/s AND keep the pressures nearly as low as I can with the larger-headed cases. And there's the point I am really headed for:

Let's assume that the action is not the 'issue' in the context of back-thrust, but rather in the context of chamber pressure - which occurs in "all directions". (Again I want to make sure no one gets the impression that I'm trying to talk anyone into anything.) The 'worry' is then, that the pressure that the cartridge will exert on the walls of the thinned barrel tenon will be excessive. Given that 'worry', why would one choose to use a smaller case that requires at least a 20% increase in chamber pressure to reach the desired 1600, f/s MV with a 180-grain bullet, when a larger headed case will in fact reduce the pressure on the (albeit thinner) chamber walls?

Without doing the complete math, I can't say for sure where the 'tip-over' point is, but there is a point below which increased head diameter, with its associated thinning of the chamber wall, is actually less "stressful" on the action than a smaller case head, with its associated thicker chamber walls, but significantly higher pressure.

Again, not trying to convince anyone of anything, rather just posing questions - not rhetorical ones - and pointing to some internal ballistic realities. Thank goodness there's plenty of room for all sorts of 'wiggling'. Otherwise we'd all be shooting .30-06s.

I'm sure your final choice will result in a 'fun' gun, and I look forward to hearing more about the project.

Paul

Well - rather simple really.  the small-head cases will still be safe at their max. pressure limit in the action and with the small barrel tenon, but with the larger cases, you always run the risk of someone trying to get to the limits of the case, which in this case will be exceeding the barrel tenon's limits.  No such danger with e.g. a case based on .357 max or 5.6 x 50R, that cadet action itself will withstand those higher pressures.
Pressure in itself  won't be the issue, but barrel wall thickness will be.  Push that .44-40 case to 50,000 psi, and I wouldn't be wanting to stand next to you...
That 25,000 limit is of no consequence for the action itself, it will easily hold a lot more (like 50,000, if the firing pin is bushed) - provided the barrel walls are able to.  and that is the weak point of using the larger dia. cases, you are actually creating a weak spot where none was.  I'm not saying you will, but someone might at a later stage - just because they can, and because there are loading data for that case or round to that pressure level which could well be an issue with such thin chamber walls.
If I were to do your project, I would keep head size down to 30-30, which would give more of a safety margin.  Never mind the final round will develop more pressure, that is of no consequence for this action.  That self-imposed 25,000 psi limit is of no real use here, you can easily go higher - but only with certain case heads.  even 0.05 of extra steel at the chamber end will add to quite a bit more safety margin.  and even if you have to run a .357 max basic case at 30,000 or 35,000, that won't be an issue. FWIW, on a 38-40 cadet, you can even see some brass peeping over the top of the block with the action closed...
I believe pressure tests on the cadet action proved that the 1st thing to give way is the barrel tenon/receiver ring.  The rest usually will hold up quite well.
To summarize:  even a full-pressure or overload on a small-head case will not cause any damage or problems (except the obvious problems like ruptured primers, sticky cases etc.) - but it could happen with a case with a larger head...    Your objective can be reached in a safer way  - albeit with higher pressure - by using a smaller case head size.