Forming 17 fireball from 221 fireball

[durango]

I bought 300 rounds of loaded 221 fireball from an estate sale. POINT OF QUESTION: I have no idea on the age of this ammo, but there wasn't any modern equipment, firearms or ammo in this sale. I'm guessing 30-50 years since the former owner had done anything with his collection.
I bought new factory loaded ammo, new factory brass (loaded), and once fired reloaded. All brass is Remington-Peters. All six plastic boxes had meticulous reloading data (except dates) with the rounds which is how I make the claim to the once fired. I have pulled down all but the factory rounds and have only been working with the once fired brass.
I'm attempting to neck this stuff down to 17 fireball but I'm having a horrendous loss due to split necks, both radially and linearly. I'm losing 40-80% depending on the protocol used. My best success has been tumble, anneal and run through a 221 fireball FL die with the decapping guts removed and then through the 17 fireball FL die. Lube used is mink oil around the base and the necks left dry (I've heard the dry neck idea from several sources, but I can't figure out why). The last batch that I did had very slight splits on the neck mouths after the 221 fireball sizing die- 3 of 7. Obviously, those three split wide open when run through the 17 fireball dies. Both sets of dies are RBCS, 221 are used and the 17 set is brand new.
While most people complain about short cases after necking down, I'm wondering if a light touch of the neck on the case trimmer would help alleviate the tendency to split after only going through the parent case size dies.
My questions/concerns are: Why is this happening? Can it be that the brass is just too old? Most accounts say that this procedure is a slam dunk, so I'm not wanting to invest in more dies. What am I missing?
Thanks for your thoughts, Steve

[country gent]

Brass does age harden some but the anneal ( if done properly) should relieve alot of that. Another may be on ammo that old is could it have been fired with corrosive primers? This also will make brass brittle over time. You might try running thru the 17 seater die first as a pre size step. This gets it down close so the sizing die can finish it easier. Ive never used mink oil for sizing but have used lanolin with good results and Imperial sizing die wax for forming. Lightly lube outside with lube and with a nylon brush or cotton bore swab lightly lube inside of the neck with motor mica or graphite. Also try annealing twice to make sure they are soft enough again. A good anneal that truly softens the brass will help alot.

[Mk42gunner]

My opinion on the dry neck for sizing down idea is that too much lube on the neck can lead to lube dents in the shoulder area of the case. If you are losing 40-80% of cases, I say try a light film of lube on a few cases; you should find out real quick if it works for you or not.

I really doubt that .221 Fireball cases were ever loaded with corrosive primers. Stranger things have happened though.

Thirty years is probably plenty of time for brass to age harden, I'd try annealing them again. I normally wait to anneal until all the squeezing is done; but you are having disastrous results now, so no sense waiting.

Good luck and let us know how it comes out,

Robert

[mart]

+1 on both the above gentlemen's advice. Anneal, light lube, Imperial or Hornady Unique, use the bullet seating die for the first round of sizing, anneal, lube the inside of the neck and use the FL sizing die for the final sizing.

[durango]

Thanks to those who have replied. I decided to try some of the new (unfired) brass today, so I annealed ten cases, faced off the mouth and chamfered in and out. First through the 221 FL die (the seater did nothing) and then into the 17 seater and promptly crushed two cases, so I finished off the last eight cases, losing only one to a split neck. I can live with that since over half the cases I have are unfired.

So, back to the once fired cases- annealed ten, started facing them off and found tiny little cracks in the neck of six of them!-lost one more during the sizing operation for a net three 17 Fireball cases. Obviously not as good a deal as I had thought at the auction, but I've got about 200 cases and six MTM storage boxes for $35.00. BUT- I still don't understand the split necks in that supposedly once fired brass. I've been reloading for over fifty years and have always used R-P brass as a first choice and have never seen this before with the R-P brass. Especially those that split radially near the shoulder.

Anyway, thanks again for the responses, any other comments are welcome. Steve

[Postell]

You need to form with a step down process. I form 17 Squirrel and 17 Heebee cases from 22 Hornet and 218 Bee cases.
Anneal your cases and neck down to 20 caliber first and then to 17 caliber the second time in the neck down process. If needed anneal again. I always anneal when I'm done forming before I fireform any cases.
You can get a reasonably priced 22 to 17 caliber die from Bullberry for about 60 bucks I believe. And with that your case loss's will be almost nothing Sir.