I have built a 7-30 Waters on a Cadet action and am having some extraction problems. It is head spaced within tolerances and I polished the chamber, but the cases still stick, no pressure signs on the brass.
I am loading factory brass with 33g of IMR 4895 showing 2200 fps. 120 g bullet. Factory ammo does pretty much the same altho to a lesser degree.
There has to be a reason for hard extraction but it is escaping me. The cartridge chambers fine with to restriction.
I also noticed that the fired cartridge will not chamber after firing.
I have never had a rifle that I built give me this much trouble with hard extraction so I am missing something just am not picking it up.
So..........any idea????

I assume you put in a smaller diameter firing pin?

Yes rebushed the block and smaller pin firing pin strikes are center of primer and pin retracts with no show of a drag mark on the case
The block will drop ok but when I get to levering the extractor back is when I run into the problem of the case sticking

The action is springing. I didn't think the cadet was sufficiently rigid for such a cartridge and are usually reserved for very low pressure things. Martinis are very strong in design, but still you have a rear locking action with thin side walls. I know guys have put 30-30 sized cartridges in them but remember what they were originally made for....
Maybe...Probably.

I assume that there is a certain amount of "give" in a Cadet action. I think what is happening is that when the action is under pressure, the bolt allows the chamber to develop excessive headspace at the peak of pressure and as the pressure recedes the elasticity in the action springs back and forces the bolt a fraction of an inch forward again, back to the original position, only the cartridge case is no longer the same size as it was when loaded. The relatively steep taper of the 7-30 is wedged back into the chamber and the result is hard extraction and the fired cartridge will no longer chamber.

You may have to resign yourself to shooting light loads. Keep in mind that the original cartridge for which the rifle was chambered is smaller in diameter than the 7-30, and even sticking to the same pressure as the original loads, the cartridge case will exert a more powerful force on the action, since the force exerted varies not only with the internal pressure of the cartridge, but also with the total area of the cartridge's internal diameter at the head. Opening the chamber up with an AI .219 Zipper reamer might alleviate the problem, since it would greatly reduce the wedging effect.

My first "varmint" rifle was a Model 219 Savage built on what was essentially a single barrel shotgun action in caliber .22 Hornet. I subsequently had it opened up to AI .219 Zipper and never experienced any extraction problems.

The .310 Greener cartridge, for which the action was originally built, is also virtually straight sided and even if the action were to give, it would have a far smaller effect on extraction.

xausa
What you are explaining makes sense, I did not consider the action springing.
I had talked to other people that had built the action on this caliber but never mentioned having extraction problems. But then I never ask just assumed (1st mistake) that everything was good.
When I got the rifle it had been chambered to 30-30 but was a hack job so I salvaged the action to build this one.
Thing is it shoots under an inch consistently with this load.
But it is going to be rebarreled into something else if this does not work out

Rolland,
I have a cadet in 7-30 waters. I keep the chamber very clean, as well as the cases. It will then grip the chamber walls to help with spring. As dpcd said, they are a "rear locker" so there is some give to them. Keeping the headspace tight, so there is no run on the breech block might help.
I have 8-10 cadet rifles in various cartridges, and have always made them work with a little playing around.

All rear locking action designs are prone this to some degree. Making it a more straight walled cartridge will help; PO Ackley proved it.
And by polishing the chamber, you made things worse; should have left as rough as possible. Brass alone will hold up to 40K psi; read Ackley. You don't even need a locking mechanism. Slightly more to it. But you get the idea.

Tom
polish may not be the right word, I used some 150 to crosshatch the chamber but as I think about it may not have been enough.
Might try a little more before giving it up completely.
Thanks to all for the help.
I learn something every day, cept it pushes out something I already knew and then I have to start over again.

I had one and shot the 25-35 with light bullets and it worked fine and also with factory ammo..but I eventually went to a SAvave 219 in rebored 25-20 to 25-35...Eventually decided the Win. 94 was the best bet for what I use a 25-35 for..Maybe some day a Ruger 1-A with a light 25-35 barrel is in the future..

You do not want a smooth chamber; that is a misconception; you want the brass to grab it. Good brass will let go; that is not your problem. Chambers are not supposed to be mirror; just like an engine cylinder bore; too smooth is a bad thing.
The clue is that fired brass won't go back in; the action is springing as I outlined above, I think. If you fired that ammo in the same chamber, but in a stronger breech, it would come right out. Back 40 explained the phenomenon.

You all can now sleep better at night cause I fixed the problem.
I pulled the barrel and touched up the chamber with 150 grit emery and reduced the load 1 grain. It extracts much better now, and the brass shows no signs of a problem. I am happy, thanks for all the advise and opinions.