Author Topic: Loading data from scratch (Read 1038 times)

M8ball · « **on:** April 06, 2006, 12:06:24 PM »

Hello. I've been handloading for several years now, thinking about building a custom rifle chambered in a wildcat round. I've got enough
basic knowledge to have a rough understanding of figuring out what
powders and charges would be appropriate for my project based on similar cases, but I'm wondering how you guys go about determining a safe starting load. Is an internal ballistics software package like Quickload the tool of choice or is there a better source?

My wildcat is essentially a .221 Fireball or .222 Rem necked to .257", but with a very long neck. I've used loading data for the .25-20, .256 WM, .257 Kimber and an Excel spreadsheet with the Powley formula to bracket what SHOULD work: i.e, H4227 or H4198.

The action used will be a Remington Model 7 or 700 shortaction.

Any help will be appreciated.

PaulS · « **Reply #1 on:** April 06, 2006, 10:53:43 PM »

M8ball,

If you can find a cartridge with a similar case capacity in the same bore diameter then you have a place to start. If not the if you use the parent case (as long as you have increased the bore diameter) you can use the same load data to start and work up from there.
The thing about wildcats is that you have to use some common sense in what is going to limit your pressure range. If you are using a strong bolt action then case and velocity will be the limiting factors. (case failure and bore errosion) If you are using a lever action then you might be concerned about the action. If you are using a falling or rolling block action then you are limited by the action more than anything else. With a break-open action then thrust is going to be the limiting factor.
There is usually a practical reason behind a wildcat and it is expected to perform in a certain action that you were not getting before. Watch you expectations and make sure it stays practical as you work loads up for it.

Reed1911 · « **Reply #2 on:** April 06, 2006, 11:32:18 PM »

PaulS Pretty much covered it, The load software will make it a little eaiser, sometimes. I've ran into a lot of errors in load software though so it pays to have a back-up and just use the software as another refrence tool. There are so many wildcats out there that you should be able to find a good starting place with established data and work from there.
More than anything else it just makes it eaiser for calculating external ballistics.

Catfish · « **Reply #3 on:** April 07, 2006, 03:23:22 PM »

I have a .25 cal. on the 221 Fireball case. I have found that the data for the 256 win mag. is safe. The .25-221 case will hold 1 or 2 more gns, of H2O than the .221 case, so you should be able to loaded it alittle hotter. It`s been along time, but I`m thinking I got 2,600 or 2,700 fps. with a 70 gn. HP bullet. I neck size with a set of .256 win. dies, to cheap to spend $ 100 for the right dies. If I were going to build a .25 cal. I think you would do better with the .222 mag. case. This case should make a good lite deer round with a 100 gn. bullet. If you have any more questions on this round you can PM me here and I`ll try to answer them.

M8ball · « **Reply #4 on:** April 08, 2006, 06:25:00 PM »

Gentlemen:
Thanks for the info. I figured looking at similar cartridges was the ticket, but being on my own I thought I'd find out if there was some kind of magic reference that the experts used. Got a followup question for you on loads. In one of P.O. Ackley's books, many recommendations are made for using near maximum loads for fireforming, the idea being that you want to blow out the case as much as possible to match the chamber dimensions. And that would make sense provided you started low and worked up. But another fellow who is quoted in the book warns against fireforming with anything less than max loads, saying that people have fireformed with a light load, creating a headspace problem, and then wrecked the rifle the next time that particular case was reloaded. So what does one do? Do you go from starting to what seems like a good maximum, junk those cases, then fireform a new set at max level and reload those?

PaulS · « **Reply #5 on:** April 08, 2006, 08:00:36 PM »

M8ball,

When I fireform my 308 cartridges for my 358 Win. I just take a loaded 308 round and chamber it - fire once and it is fire formed.
You can do this in most bolt action rifles that have good extractors. I don't know if i would do it in some lesser arms. My brother does the same thing for his 6mm TCU in a Contender. It seems to work ok and the only caution would be that if you get split cases (doesn't happen with new brass) then you shouldn't do it. Split cases will cause etching of your chamber and ruin an otherwise good gun.

Reed1911 · « **Reply #6 on:** April 09, 2006, 12:14:38 AM »

There are some very different views on fireforming that both have merits and drawbacks. On FF with a full house load, Ackley is mainly talking about going from standard to improved IIRC. In which case it should work with very little problems. But just keep in mind that the difference between say 30Kpsi and 50Kpsi, as it relates to brass with no support, has no effect. What I mean is that at 30Kpsi the brass will form just fine to the new chamber, moving the pressure even higher is only going to place more strain on everything. When it comes to rimless cartridges, I load a mild load of fast (for caliber) powder and cheap bullets and go to plinking. I keep the bullet seated out far enough that when I close the action it is jammed tight into the lands and the case head is tightly pressed to the breech face/

krateboy17 · « **Reply #7 on:** April 28, 2006, 05:43:52 PM »

I belive John Wooterts had a wildcat 25 based on the 222 Rem. he called the 25 Copperhead. Would have to dig around to locate if you were interested.

M8ball · « **Reply #8 on:** April 30, 2006, 06:38:11 PM »

Krateboy17:

I know of the the 25/222Copperhead from Donnelly's cartridge conversion book, but I haven't been able to locate Wootter's article. I would be interested to see what you're able to find on it. I didn't have much luck online, although the Donnelly book mentions it's in Rifle #22.