Shooters Forum banner

designing your wild cat

13K views 16 replies 7 participants last post by  Shummy 
#1 ·
How did you make you own wildcat. Is there a software you use? Can someone pm me. How do you go about your pressure limit powder charge. What degree of neck ?
 
#3 ·
My wildcat...

I have one I have been thinkering with for over two years. It's a 300RUM case shortened to 30-06 length, has a 30-degree shoulder angle, the shoulder on the wildcat is at the same location as on the 30-06 case and it has a neck .400 inches long to reduce throat erosion. I have recently contacted a CNC shop I found on the net and am in the process of having them spin up three of them. The dummies will be drilled and reamed to hold a .308-inch bullet and have a short, thin sprue on the bottom so the model can stand up on a display board.

I cut a 300RUM case to the same height as the shoulder on a 30-06 and found the volume to be 5.20cc, which equated to anywhere between 76 and 80 grains of magnum-type powders. I used RL-22, H4831SC, H380 (WC852) and H4350 to generate the charge weights. Weight of water in the cut-off case was 80.2 grains, which I converted to cubic centimeters. I also cut off a 300WSM case (my current target boomstick is chambered in this caliber) and found its volume at the shoulder to be 4.39cc. My plan is to remove the barrel, cut off about 35mm of its breech length because the 300RUM is of a lesser lower datum diameter than a 300WSM, rechamber for the wildcat and see what velocities I get. My rifle is a long-action piece chambered in 300WSM. Feeding is not reliable. Sometimes it will pick up a shell; others times it won't. You really see if you're a flincher when you touch off an empty chamber. I get 2907 fps out of 65 grains of RL-22 with a 180-grain Sierra Matchking bullet. I am hoping to get 3100-3200 fps out of my wildcat. Below is a sketch of it for your discussing and recommending pleasure...



I've been fooling with this idea since August of 2008. Never got around to doing much with it. Always found another use for the money. I figger I need four or five forming dies, each one of which will require a reamer be made for it. Then I will need a roughing reamer and a finish reamer. Money, money money. Time, time, time...
 
#4 ·
Well, I drew it up on RCBS Load. I’ll make a Jpg small enough to post here is a bit. Feeding, breaking ice and watering now. I have had a doughnut and tea but I could use some waffles!

I estimate total water capacity at 91.6 grains. With a Speer 165-grain flat base bullet (1.155” oal) seated .309” I estimate the water capacity as 85.8 grains.

Using IMR 4350 as a base, I estimate a powder capacity of 75.22 grains - uncompressed. I estimate 76.0 grains of IMR 4831. These are just cubic estimates.

We are not far off in our gross estimates. I run it on Powley in a bit - it doesn’t take me long to play with a lump of coal!

Whose program are you using?
 
#6 ·
The changes continue...

Below is the latest sketch. I have decided to go with the 375Ruger case because it is available as cylinder brass. This means I will have to have Krieger make me a new barrel, but that was always a possibility with this project. Shoulder angle is now 28 degrees. The plan now is to contact a maker of forming dies and ask how many do I need for a smooth, gentle reshaping of the cylindrical cases down to something that will chamber. For those who know: Are forming dies shape-specific? Or do they just crunch the brass down along standard lines to where the neck is the right length and the shoulder is in the right place enough to get the round to chamber? I was thinking four or five dies that slowly move the brass to a shape just short of the final shape, with the neck and shoulder bends about .030 inches below where they'd be once the case is fireformed. The ready-to-fireform case is chambered, fired and bango! we have a perfect case. Is that how it works?

 
#7 · (Edited)
The number of form dies and whether or not fire forming is a “serious“ event or a simple matter is determined by the original brass shape and how radical the change is. Generally the shoulder must be snapped out sharpe and body taper adjusted etc.
Most of the custom die makers prefer to have at least three cases fired in you chamber in order to make form, trim and sizing dies.
If other dies will get you close enough to chamber a case you can use a fast powder with a case full of cream of wheat or cornmeal to form the cases you need.
Form trim dies are very handy to have but not always essential. They are handy enough that when I recently saw a set of 25-35 form dies on sale at Midsouth I bought them, despite the fact I have making 25-35 brass from 30-30‘s for years using a variety of dies.
Ask your library for an interlibrary loan of

Handloaders Manual of cartridge Conversions by John Donnely

Designing and Forming Custom Cartridges by Ken Howell

Home Guide to Cartridge Conversions by George Nonte

These books will give you a crash course in case forming with and without special loading dies.
 
#8 ·
Handloader's Manual of Cartridge Conversions, by John Donnely

Designing and Forming Custom Cartridges, by Ken Howell

Home Guide to Cartridge Conversions, by George Nonte

These books will give you a crash course in case forming with and without special loading dies.
Are these available for purchase at any of the usual on-line places?
 
#9 · (Edited)
Yes, and no. You will be astonished what the current asking price for Donnelly’s book is. The book is currently out of print. The drawings - if you can call them that are poor - the text is very good. Current asking price for this book should be $25.00 to $30.00; I have seen them offered for $150.00. This book should be asked for on an interlibrary loan.

Ken Howells book is also out of print. Ken is trying to get it reprinted now but his health is poor and this is a difficult task for him now. The current asking price for this book exceeds $200.00. This book is one of a kind and was an instant classic when printed. I believe the current asking price should be between $75.00 and $100.00.

The current asking price for Nonte’s book exceeds $100. This is a good book but it may be worth $30.00 to $50.00.

If I could sell my books for what these dealers are asking I might seriously consider doing so - well, maybe not!
 
#10 ·
Not to be had...

Contacted Remington, looking for 300RUM basic brass. They wrote back telling me that they do not offer any of their brass in basic. Well, they should...
 
#11 ·
Ruger basic factoids

Congrats on figuring out that the big Ruger has it over the RUM. It's all business. You can go down in .050" stages. My form set from Hornady does this in four steps ending with my Boer 8mm. But, step two was a real bear, so I ordered a stage 1.5 that only changed the taper and put a very slight straight neck into the stage one, .450 cal case. This evened out the Godzilla force needed for stage two, .400 cal., which was a bottleneck. Stage three makes a .35 cal. and the last stage is a F.L. Sizer for the Boer 8. Note that my stage 1.5 is also a file trim die. That's why Ben Syring put the cheezy neck into it. You have to support the case mouth against the hacksaw and file. This trick also really brought the final case trimming down to size.
I've run into two cases per box that just will not neck down. The anneal must not be perfect at the factory. Their necks get a striated look, and then collapse. Also note that I found out that I could reform 375 Ruger brass, but doing so means .002" thicker necks, over the reformed basics. (+.001" wall thickness). Those Hornady reform dies are a four to six month proposition, but are magnificent tooling. The single file trim stage 1.5 was only three months out. FWIW, the Ruger factory cartridges are too short in the necks. They may thicken their necks a bit to compensate for this. So be sure you specify a hunting chamber with enough daylight over your necks to let the brass back away from the fired bullet. This is probably the hardest critical dimension to call when you send in your reamer print. And be sure to remember to order your "Go" gauge at the same time. Your smith needs it to do additional chamberings that are safe with the cases made from your reform and F.L. dies. The Ruger is a rimless, so they will all head-space on their shoulders. It's better than belts, but you have to pony up an extra $30 or so for your custom "Go" gauge. But it's like finalizing a DVD build. Every single chamber will work safely with the cases your custom reform die set produces. So any down the road reloading die set will work, unlike such belted jobs as the .416 Taylor which different gunsmiths have juggled shoulder dimensions to gain capacity, so theirs' will shoot a little faster, than the next guy's, but needs a different set of dies to reload for.
Good luck with your baby.
 
#12 ·
Contacted Dave Manson about the reamer. This is what he sent back from the sketch (in this thread) I sent him. I have since changed a few dimensions on the cartridge, so this picture is old. It's forever a game of change, isn't it? One of these days, I'll finalize it and go with it...

 
#13 ·
Both Quick Load and Load from a Disk have custom cartridge design programs built in. It is quick and easy to adjust all the different parameters.

Plus on what has already been said, plus you can check out CH4D for already available reloading dies. I'm guessing there is already something available or close to whatever you might be thinking of. PT&G will make reamers to just about ANY thing you can design and CH4D can make the reamers.

Luck
 
#15 · (Edited)
I have those. Got them from the man who makes them. He is all sold out of them. My set is available for sale, should anyone want them. They only do .473 rim stuff-- nothing bigger. No help at all for magnum forming...

This is where we are now with my wildcat. Reamer is ordered and a drawing has been emailed to the barrel maker showing the contour and fluting, et cetera.

 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top