I have always been intrigued by the less common and wildcat cartridges. I've decided to invest in it this year, and do some experimenting. The cartridge I decided on is a 45-70 case necked down to .358 to use in a lever action to use as a brush gun for deer and elk. My reason for wanting to do this is plain curiosity, and as a learning experience. I'm not trying to develop a crazy new cartridge that can do what none other can, this is just for the fun of it. That being said, from anyone who has made their own wildcats before, what advice do you have for a first timer? What would the process be? Where is a good place to have dies made? I probably would need to size it down in more than one step, if so, how many? What other equipment would I need? And a new barrel, I would like to use a Marlin guide gun in 45-70 and re-barrel it for this round. How feasible is that and where can I get it done? I've got lots of questions, any advice would be appreciated!
Wildcat "Basics?"
- Thread starter Fnusa
- Start date
I have not developed a wildcat from scratch before, but I have spent most of the last 35 years trying to load for the 5.7mm Johnson (a necked down 30 Carbine round developed by Melvin Johnson) and since what you're talking about is simply necking down an existing cartridge and re-barreling an existing rifle, there's considerable overlap.
Go slow.
Do your homework.
Get (or have created) drawings of the parent cartridge and then use them to help you come up with drawings of the proposed cartridge. Remember that while it may seem simple to say, just neck a 45-70 cartridge down to .358, but where does the new neck begin and what angle should it follow will need to be reduced to a mechanical drawing of the case so that the tooling to make it can be produced.
Unless you've got expertise in non-ferrous metalwork, you'll probably need some support from a machinist or engineer with knowledge in the field. Don't hesitate to spend the money to buy the knowledge you need.
RCBS closed their custom shop last year so you might want to check with Redding since they already have expertise with wildcats. If not, you should be able to find a machine shop in driving distance that can do the work for you.
In the case of the 5.7mm Johnson, the case is drawn down from 308 to 224 in three steps; 1) initial forming of the neck in a forming die, 2) secondary forming in a so-called trim die where the case is also trimmed to length, and 3) final set of the neck with the sizing die.
FrankenMauser
New member
Hornady still makes custom dies, as does CH-4D.
I would start by getting a chamber drawing done.
Have the reamer made.
Chamber and headspace the (likely new) barrel.
Then there is a fork in the road, with a choice to be made:
1. Figure out a way to get some cases formed well enough to fire - even if they need to fire-form in the chamber. (Such as necking down to .41 caliber, then .375 caliber, then shoving the case partially into a .358 Win die to form the neck well enough to finish by fire-forming.)
Then send some fired cases and/or the chamber drawing off to have dies made.
2. Send the chamber drawing off to have dies made, as soon as you're ready to commit.
Load and fire.
(This one is better, but not all companies will make dies based solely on a chamber drawing.)
There are few 'smiths across the country that are willing to machine barrels for Marlin lever actions. The barrel and machining will probably cost as much as, if not more than, the chamber reamer and custom dies.
It can be done. It's just that very few gunsmiths want to touch Marlin barrels, due to the machining required.
My recommendation would be Ranger Point Precision. They specialize in Marlin levers, and do plenty of wildcatting and custom builds. They may try to talk you into a gaudy pink and blue DuraCoat finish, but it's worth the hassle of saying no, since their mechanical work is very good.
I would start by getting a chamber drawing done.
Have the reamer made.
Chamber and headspace the (likely new) barrel.
Then there is a fork in the road, with a choice to be made:
1. Figure out a way to get some cases formed well enough to fire - even if they need to fire-form in the chamber. (Such as necking down to .41 caliber, then .375 caliber, then shoving the case partially into a .358 Win die to form the neck well enough to finish by fire-forming.)
Then send some fired cases and/or the chamber drawing off to have dies made.
2. Send the chamber drawing off to have dies made, as soon as you're ready to commit.
Load and fire.
(This one is better, but not all companies will make dies based solely on a chamber drawing.)
There are few 'smiths across the country that are willing to machine barrels for Marlin lever actions. The barrel and machining will probably cost as much as, if not more than, the chamber reamer and custom dies.
It can be done. It's just that very few gunsmiths want to touch Marlin barrels, due to the machining required.
My recommendation would be Ranger Point Precision. They specialize in Marlin levers, and do plenty of wildcatting and custom builds. They may try to talk you into a gaudy pink and blue DuraCoat finish, but it's worth the hassle of saying no, since their mechanical work is very good.
I have forming dies that will take the 45/70 down to 338 (I think) because I have not gone through my forming dies in a few years. I have little interest in rediscovering wildcats. I would check to see if the wildcat you are looking for has been developed.
At the time the forming die cost $175.00 and it did a magnificent job/
F. Guffey
