Just out of curiosity, has anyone here designed, had a reamer built and chambered a gun for a cartridge? If so, might you explain your cartridge and why you designed it?
Ed

Designing and building a cartridge is not the hard part. The tough part is finding a cartridge that hasn't been invented yet. I have had the pleasure of being the gunsmith on a current project of a medium bore African game cartridge. The math wizard behind the design came up with the idea to replace an outdated rimmed cartridge with one to fit on a standard mag bolt face. For reasons of legality I can't go into much detail. But if you desire to design a round yourself, contact a good reamer maker. I suggest Dave Manson, he has been wonderful on this project. Have a reamer made, cut a chamber, form some brass and arrive on finish data for the round, ( i.e. make sure it will do what you designed it to do.)
At this point contact a die maker, we worked with Hornady, to make your reloading dies. And a company to headstamp some brass for you. Now you can name a round after yourself. It is a long process if you want to produce it commercially, but if you just want a wildcat for yourself, make one you can use produced reformed brass from another caliber and dies that can be reworked for yourself. And by all means be careful and don't forget to have fun.

Welcome to the site wool1!

Intersting good info, thanks for sharing.


-DallanC

Wool1,
Thanks for the reply; I was just wandering if there was another designer on the forum. This is what I had in mind:

My last design was a .308 caliber cartridge that was usable in a handgun.

The intent was to:
A) Use .308 rifle bullets, their BC and SD in a handgun
B) Use rifle bullets within the framework of an existing revolver
C) Escape the "revolver" bullet design now used for over 100 years
D) Design a manufacturable new cartridge for hunting and competition

The concept required:
1) A non-bottleneck case with sufficient taper to allow positive extraction
2) A case that was short enough to permit use of a rifle bullet in revolver
3) Design without getting into the M-N structure or style
4) The case to have sufficient capacity to drive a 150-grain bullet to 1500 fps and a 165-grain bullet to 1350 fps.
5) Accuracy of .500 inches at 50 meters.

The cartridge was initially chambered in a revolver I built and has proven to work quite well. However, I stopped shooting the cartridge and ended its development. The company that was to manufacture the revolver is now gone from the landscape.

Again, thanks for the note. By the by, I prefer Clymer products as I know the good folks who bought the company, about 5-6 years ago, and they make a fine product, are interested in shooters and support the shooting sports with donations. Manson might be great, but I do not know them.
Ed

I designed a round based on the 30-06, actually you can form the brass I think from the cartrage never built reamers or anything though. Just a pet project a while back when I was bored

Its a 30-06 Case necked up to 40 caliber and cut back slighty to remove alot of in my opinion the overly expanded neck of the original 30-06 brass.

Someday I hope to make it and since I'm going into Tool and Die I figure I can build the reamers and the reloading dies myself, I attached a picture of my 40 Caliber "Special RimLess Hunter". Reason I say RimLess in the name is because I thought of doing the same thing to the 303 British possibly.

PS I know my drawing isnt perfect but its just in the "idea phase"

Dimitri

Demetri,
Interesting cartridge project. However, the 40 caliber in the 06 brass would look a lot different and like the 400 Whalen and 411 Hawk, would require a good shoulder to headspace upon. If you lenghten the neck to .301 I think it would result in a more stable neck and bullet hold situation.

You might read the following and other articles on the shoulder angle required, as you go along:

www.z-hat.com/smashing...e_myth.htm

Note the 400 in the bottom right of the page.
Ed

SwampFox,

Shucks never head that Whelen made a 40cal version.

But I did say my design was "expermental" and in my defence I dont got the book on all the different rifle cartrages that have been made

Still althougth hard to "head space" I might refine my idea to get the proper sholder area somehow and increase the neck as you said, and still try building it

Tell me my design in my mind was ment to hold smaller 150gr, 180gr and 200gr handgun bullets in 40caliber not heavier rifle bullets. What do you think ??

Dimitri

Dimitri,

Have you done any stabilization computations? Twist rate ect.? Check with a couple of barrel manufactures and see if they can do a full length .400 barrel. You might run into alot slower twist rates then you may need. I am not personally familiar with any, I am only familiar with lever gun barrels (38-40) originally designed for black powder velosities

I have also seen the crimp be a problem for on higher velosity 38-40 as there is not a bullet manufacture yet to make a 40 cal bullet with a crimp groove.

By no means let my questions or comments detour your ideas, most of our best cartridge designs we have today started as experments.

At least I am consistant at misspelling velocity!

I agree with using Clymer their work is excellent and they will work with you and talk to you if they have concerns. I have a couple of reamers from them. As for dies you have a lot fewer choices today than you used to. RCBS used to make specialty dies but I don't think they do anymore and there are a coupl of others that won't do the custom stuff. Hornady still does and they are good at it. It is expensive to have the reamers and dies made but if you do the research ahead of time its worth it to see the results that you expected. My two latest cartridges were straight wall cases and I only needed the two reamers and to modify existing dies to get the job done. I haven't made any dies yet but I am going to attempt it just to see if I can.

Wool1,

Lilja at www.riflebarrels.com makes a 40caliber 1-16 twist barrel which also happens to be the standard twist rate for the handguns chambered in such rounds like the 40 S&W

I dont know if this would be "Ideal" in terms of twist rate as my round is a rifle round and will be shooting the same bullets up to 2700fps though

As for head spacing I came up with a idea. Make a soild brass plug that has a flat front shaped like how the rifle brass would be but just till the start of the taper from the body to the neck that way its not headspacing off the sholder but instead off the top most part of the body What you think ??

Dimitri

Several points and questions raised.

RCBS still lists custom dies on their web site. But just about any die maker has a custom shop; all we need is a checkbook and about 6 months lead-time.

The headspace for rimless cartridges should be on the shoulder. The article about the 400 is an indication of how a few degrees change in shoulder angle can be and is critical for the 40-06.

The use of pistol bullets in a modern high velocity rifle is rife with problems that are inherent in the bullet's design. Pistol bullets are designed to hopefully expand at 1100 to 1500 fps. High velocity simply causes them to spin off the jacket, strip over the rifling or disintegrate upon contact. The worst problem is the abysmal BC due to the 100-year-old design used as the base for all pistol bullets. Sort of like shooting a 1 gallon paint can.

I do not recall ever seeing a crimping groove in a standard production rifle bullet, outside of a cast bullet. Cannelure, yes, groove, no. But a cannelure is needed and one is not present on the selected bullet, a cannelure tool can be purchased.

As to barrels, there are barrel makers out there that will just about make anything we can imagine. Caliber, twist rate, button, broach, cut, forged, etc.

If a barrel is needed for a BP lever gun cartridhe, suggest a contact of Wind River Rifle Company; they specialize in restoration work and make barrels for that very purpose. They own and operate two rifling machines (button and cut) and have 30 plus years experiance in barrel making. You cannot tell one of their new barrels from a 100 year old Winchester, Ballard or Marlin. including the lettering. They can also duplicate the original finish on most old guns. Come with a well-endowed checkbook.

The neck on larger caliber cartridges should have at least .250 inches in bullet seating depth, without the base of the bullet extending below the base of the neck. For a magazine rifle, the neck should be a bit longer to insure stability while being fed from the magazine. Thus the reasoning for the longer neck on the 40.

"Velocity changes stability." An unstable bullet is unstable at any velocity obtainable by that barrel. The twist rate must be changed to stabilize an unstable bullet. The needed twist rate to stabilize a bullet is based on the diameter and length of the bullet, not its velocity.

By the by it appears that you might have a capacity from 65 to 70 grains of water. I have not found a bullet length for the 40, otherwise, I could give you a computer generated load, pressure and velocity.
Ed

Swampfox,

I read the artical but I think its mainly problems with manufacturing and keeping the infromation of the round a "trade secert".

Quote::

The. 30-06, .25 Whelen (.25-06), .35 Whelen and .38 Whelen all have a shoulder diameter of .441. "The ORIGINAL .400 Whelen shoulder is .458". When and how this information got lost to modern riflemen and writers I have no idea. Many 400's that were made in later years for which I have measurements have the .441" shoulder; this is also true of many resizing dies.

That sounds to me less of a rounds problem with headspace but manufacturers not making proper dies, ammo and the like for the 400 Whelen. People assumed it was designed the same as the 25-06 and the other Whelen's which cased exessive headspace because of the much smaller sholder.

Quote::

Because of all the bad press many of these rifles have been rebarreled or modified in some way. An early engraved G&H I know of was re-chambered to a belted magnum case so it would have the belt to headspace on.

See this is what was I talking about, execpt instead of headspacing with a belt that the 30-06 case doesnt have I'd head space using the neck so the measurements would be taken from the 1.798" from the base of the round

Mind you the 40 Whelen in my opinion failed because there was no standard so the exessive headspace wasnt as much caused by the rounds lack of a larger sholder but the headspace difference with the neck being .411 instead of .458 which is WAY too small.

You are right about the pistol bullets though. Which poses a problem as I wanted this round to be good for the Taylor Knock Out value compared to the 308 instead of just the larger 300gr bullets the 40calibers in rifles are known for

TKO Factors (at 2700fps)
Grains _________ 308cal Value _________ 40cal Value

150gr ....................... 17 ............................. 24
165gr ....................... 19 ............................. 25
180gr ....................... 20 ............................. 27
200gr ....................... 23 ............................. 30

As you can tell I am a beliver of the idea of a bigger bullet in diameter is better. The bigger the bullet in diameter the bigger the "Permanate wound channel", so Taylor's KO factors make sense to me

Plus with the lighter bullets it means that there will be less recoil then shooting a bullet weighing in double then the ones I want to shoot. Like the 40-42 calibers that shoot 300-400gr rounds.

Dimitri

Demetri,
You will need to headspace off the shoulder and as pointed out in the article, the shoulder on the 40-06 is critical.

I just went one step further, if the body is the same length, the neck is the same diameter and you increase the diameter of the shoulder, you increase the angle of the shoulder at the same time. In the case of .441 VS .458, the difference is but .0085 per side. Not much, but the difference between success and failure.

I think you may be trodding on the edge of the old argument of light and fast VS big and slow. In my experience big and slow recoil is much better than fast and light, if the energy levels are the same, in a big bore rifle. I like the push recoil a lot better than the sharp slap.

I did a lot of experimenting when I was shooting bowling pins and trying to break records. I finally worked out the very best load for energy VS recoil. It was a big bullet and a light charge of fast burning powder with a moderate pressure curve. The same principal applies to big bore rifles.

You might consider defining what you want the rifle to do, bears, deer, etc., then build the gun around the intended purpose, based on the needed energy and expected range.
Ed

SwampFox,

Thanks for the reply

I guess when I start building dies and the like to try this out I'll make the diamentions so that there is a larger angle. Although now that I know Whelen did make his first I guess its not "original"

My purpose for this was just to have a round similar in balistics to a 30-06 or 308 with a larger bullet for a general purpose rifle round. Not arguing much about light and fast, and big and slow, more into "bigger diameter" with the same weights and speeds as the 308

The logic that I used to come up with the "40-06"

1) Wanted to have a round similar in speed and energy as the 308.
2) Wanted it close to the same case lenght of the 308 (Only 0.100 difference).
3) Needed to pick a common case size to be able to get brass to make the wildcat.
4) Needed it to have the "standard bolt face" to make it easy to adapt to a firearm.
5) Wanted it to be "unique" and since I didnt know of many 40caliber rounds I figured it was "uncharted territory".

Now because of thouse requirements I figured using a 30-06 case and forming and trimming will get me the case I require. And I also thought I could use hunting handgun sized rounds in the round for 150-200gr bullets.

I'm going to have to draw up some proper CAD drawings of the round sometime soon

Dimitri