» Advanced

Go Back   Shooters Forum > Rifle and Rifle Cartridges > Wildcat Cartridges
Register FAQ Members List Donate Calendar Search Today's Posts Mark Forums Read



Reply
 
LinkBack Thread Tools Rate Thread Display Modes
  #1  
Old 12-24-2010, 03:58 PM
Beartooth Regular
 
Join Date: Feb 2010
Posts: 408
designing your wild cat


Registered Users do not see the above ad.


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 ?
Reply With Quote
  #2  
Old 12-24-2010, 05:56 PM
Beartooth Regular
 
Join Date: Nov 2001
Posts: 5,577
Start by doing a lot of reading.
Start your reading with Designing and Forming Custom Cartridges by Ken Howell.
Then P.O. Ackley’s books Handbook for Shooters and Reloaders.
Firearms Pressure Factors by Lloyd Brownell is a must have book. Fortunately, it is available on CD from Wolfe Publishing at a reasonable price.
Then ask your library for Wildcat Cartridges by Richard Simmons and Principles and Practices of Loading Ammunition by Earl Naramore.

Ken Howells book will start you off by seeing a lot of what is available and giving you a basic understanding of cartridge brass and how to form cases.
Ackley’s books will help you understand pressure, barrel and action strength along with their relationship to one another.
Simmons book will show what was done in the past.
Narramores book is still the end all for the amateur on cartridge brass and the basics of pressure and load technique.
There are other books but these will get you started.

I suggest the computer program RCBS Load. Load has a cartridge designer function that is easy to use. The cartridge designer allows you to compare case capacity instantly as you adjust the shoulder angle, shoulder diameter and case body length.
Other features which show you the case capacity in grains of powder (good powder database) and in grains of water along with color printing of the case and an excellent external ballistic calculator. You are able to vary bullet seating depth and neck length to tailor your cartridge to your requirements.

I also suggest Load From A Disk. There are several reasons I suggest Load From a Disk as opposed to more sophisticated programs such as Quick Load. Load From A Disk is simpler - quicker to master - and uses IMR single base powders for basic comparisons. IMR powders are very predictable and it is easier to understand and estimate pressure. Personally, I use the Powley Computer which is the slide rule version.

Others will stump hard for Quick Load but I believe it will slow down the learning and designing process.
Remember you will need a chronograph for all of your load development. With a personal wildcat, you are stepping off into the unknown. Even with some well-known wildcats the availability of new powders and bullets puts you out where no one has gone before.

It is very important to establish your goals before you begin designing your cartridge. What will you use the cartridge for? What bullet weights? What velocity goals? What rifle action will you use - what pressure is the action designed for?

What sort of wildcat are thinking about? It is fun to discuss our cartridge dreams and ideas.
__________________
slim
Reply With Quote
  #3  
Old 12-24-2010, 07:40 PM
nvshooter's Avatar
Beartooth Regular
 
Join Date: Oct 2010
Location: Nevada
Posts: 1,892
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...
Reply With Quote
  #4  
Old 12-25-2010, 06:03 AM
Beartooth Regular
 
Join Date: Nov 2001
Posts: 5,577
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?
__________________
slim
Reply With Quote
  #5  
Old 12-27-2010, 01:24 PM
Beartooth Regular
 
Join Date: Nov 2001
Posts: 5,577
Unfortunately when I made these small enough to post they lost a little. I’ll only post one drawing and a color drawing just to give you an idea of what RCBS Load can do. It took about three minutes to make the drawings and save them to a file.
Attached Thumbnails
designing your wild cat-c-medium-web-view.jpg   designing your wild cat-color-medium-web-view.jpg  
__________________
slim
Reply With Quote
  #6  
Old 01-08-2011, 01:22 PM
nvshooter's Avatar
Beartooth Regular
 
Join Date: Oct 2010
Location: Nevada
Posts: 1,892
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?

Reply With Quote
  #7  
Old 01-08-2011, 01:36 PM
Beartooth Regular
 
Join Date: Nov 2001
Posts: 5,577
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.
__________________
slim

Last edited by William Iorg; 01-08-2011 at 01:40 PM.
Reply With Quote
  #8  
Old 01-08-2011, 03:37 PM
nvshooter's Avatar
Beartooth Regular
 
Join Date: Oct 2010
Location: Nevada
Posts: 1,892
Quote:
Originally Posted by William Iorg View Post


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?
Reply With Quote
  #9  
Old 01-08-2011, 05:19 PM
Beartooth Regular
 
Join Date: Nov 2001
Posts: 5,577
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!
__________________
slim

Last edited by William Iorg; 01-08-2011 at 05:21 PM.
Reply With Quote
  #10  
Old 01-11-2011, 08:32 AM
nvshooter's Avatar
Beartooth Regular
 
Join Date: Oct 2010
Location: Nevada
Posts: 1,892
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...
Reply With Quote
  #11  
Old 01-25-2011, 10:04 PM
Beartooth Regular
 
Join Date: Nov 2006
Posts: 991
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.
Reply With Quote
  #12  
Old 02-20-2011, 09:05 PM
nvshooter's Avatar
Beartooth Regular
 
Join Date: Oct 2010
Location: Nevada
Posts: 1,892
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...

Reply With Quote
  #13  
Old 02-22-2011, 10:59 AM
NFG NFG is offline
Beartooth Regular
 
Join Date: Feb 2006
Posts: 300
Thumbs up

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
Reply With Quote
  #14  
Old 02-23-2011, 07:12 AM
Beartooth Regular
 
Join Date: Mar 2010
Posts: 644
http://www.shadetreeea.com/caseDieSet.html

This is the only inexpensive alternative to case forming dies that I am aware of.

You could try to machine your own by using drill bushings and a die blank, but unless you are a machinist...
Reply With Quote
  #15  
Old 05-02-2011, 12:12 AM
nvshooter's Avatar
Beartooth Regular
 
Join Date: Oct 2010
Location: Nevada
Posts: 1,892
Quote:
Originally Posted by kludge View Post
http://www.shadetreeea.com/caseDieSet.html

This is the only inexpensive alternative to case forming dies that I am aware of.

You could try to machine your own by using drill bushings and a die blank, but unless you are a machinist...
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.



Last edited by nvshooter; 05-02-2011 at 12:16 AM.
Reply With Quote
  #16  
Old 05-03-2011, 07:17 PM
Beartooth Regular
 
Join Date: Mar 2010
Posts: 644
I like the premise of this cartridge... Now you know you're going to have to build a couple more rifles and neck it up to .338 and .358, right? And maybe neck it down to a barrel burning 7mm.
Reply With Quote
  #17  
Old 05-03-2011, 10:02 PM
Registered User
 
Join Date: May 2011
Posts: 1
Hi All.
First post, been reading a bit thought I'd share my wildcat project.
I call it a 300 SLAM (Short Lapua Magnum)
The top bullet is a 240 SMK and the bottom is the new 225 Hornady.




Shummy

Last edited by Shummy; 05-08-2011 at 02:14 AM.
Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
How do I reform a commercial case to a wild cat case seatleroadwr Wildcat Cartridges 35 01-30-2011 10:20 AM
.327 magnum comments / opinions Sandman1 Handguns 27 06-10-2010 02:35 PM
Feline Physics Ross Clifton Humor 2 06-20-2009 04:34 PM
Darned Cat jodum Humor 1 09-22-2008 06:51 PM
Close encounters of the cat kind faucettb My Neck-Of-The-Woods 18 07-28-2008 06:39 PM


All times are GMT -8. The time now is 05:42 AM.

< Contact Us - Shooters Forum - Archive >

 
 

All Content & Design Copyright © 1999-2002 Beartooth Bullets, All Rights Reserved
View Privacy Policy | Contact Webmaster | Legal Information
Website Design & Development By Exbabylon Internet Solutions
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0 PL2