Ballistics vs. Cartridge Design

G

Gunslinger

Moderator
To better articulate my question let me begin by giving my reason for asking.

I am currently building a custom S&W 657 for personal use. I am leaing toward rechambering it to accomodate a hybred .44 mag. cartridge necked down to the standard .41 mag. diameter.

I know there are advantages to be gained in knecked cartidges in terms of increased velocity resulting in greater energy.

Now the question. Why?

It seems simple but once the dynamics are actually considered the reasons, at least to me, aren't so simple.
Prior to the introduction of smokeless powder a large case volume was required to accomodate the black powder needed to produce "magnum" level loads. However with the advent of smokeless powder the added case volume is not needed or used. To use the modern .308 for example. The .30 caliber case could easily hold sufficent (smokeless) powder to power the bullet to the same performance levels if it was *housed* in a straight case design.

What am I over looking?



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Gunslinger

We live in a time in which attitudes and deeds once respected as courageous and honorable are now scorned as being antiquated and subversive.
 
Gunslinger. Your 41x44 mag sounds interesting. There may be a problem though. Check this out with the gunsmith in the smithy. I think you might have trouble with fired cartridges backing up and tying up the gun. Smith & Wesson dropped the .22 Jet for that very reason.
To try and answer your other question, I think the shoulder affects the burning rate of the powder. Some expert have said that the steeper the shoulder, the longer the powder stays within the casing, therefore building up higher pressure, whereas the straight case allows the powder to be blown into the barrel,( while still burning) and causing lower pressures. (I think I got that right. Anyway, just my (WAG) thoughts on the matter. Do check out what I said about the setback problem thogh.
Paul B.
 
Short answer: necked cartridges have a greater powder to bullet ratio.

Why does this matter? We know that if you're using Unique, for instance, 10 grains won't fill the case on your .44 mag, so why not just fill that puppy on up with it?

The answer to every question relating to maximums on powder in cartridge loading is, of course, "Pressure."

A .44 case will give you a greater capacity for powder than a .41 case. This means that you can pack more relatively slow pistol powder (2400, H110) into the case to push out the same 210 g. .41 bullet.

Another consideration is the relative surface area of the bullet. Using my rusty geometry, I find that, given the same length bullet, a .44 bullet will have a greater surface area than a .41 bullet. (well duh!) A 1" long bullet of .429" will have a surface area of 1.3477421", whereas a .41" bullet 1" long will have a surface area of 1.2880519". The greater the surface area per given weight, the greater the pressure.

Oh, but I said of a given weight, didn't I? Well, obviously the 1" .429" bullet weighs more than the 1" .41 bullet. To be of the same weight as the 1" .429 bullet, the .41 bullet will have to be 1.09458" in length.
This increases the outside area of a .41" cylinder to 1.498758", which is where I throw up my hands and say "Heck, I dunno!" If we were talking about solid wadcutters (we aren't), this would be pertinent. If you were concerned with Ballistic Coefficient (you shouldn't be), this would be a consideration. (Same B.C. for lower pressure.)

(If you can't tell, I thought I was going to take this someplace, and well-disproved my original hypothesis.)

Regards,
L.P.

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If you're *not* a member of the NRA, what *are* you doing to protect your rights to enjoy yourself on this Bulletin Board?
Do SOMETHING!
 
Why not try this wildcat out in T/C Contender? If the idea is viable, I think it would be one hell of a round in a Desert Eagle. :)

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May your lead always hit center mass and your brass always land in your range bag.

~Blades~
 
Ive a question concerning this, what is the diameter of both of these bullets?, I have nothing around I can check but is there a significant reduction in diameter...I dont recall that there is, so this would probably be a mild shoulder at best---it would be interesting to see what the chronograph would say....fubsy.
 
Diameters are:
.41 magnum/.410
.44magnum/.429

The catridge is already being chambered in the T/C Contender however I've yet to see any ballistics.

My plan, if it is fesible is to retain the factory cylinder in .41 mag. and rechamber a nonfluted auxillary cylinder in the wildcat round. Thus creating a dual caliber revolver.

I had wondered if it was simply a matter of kentic energy simlilar to channeling water into progressively smaller areas until an increase in preasure is obtained. But to be honest after having scratched my head over the theory for some time now I'm still perplexed. Thus my reason for asking ya'll.

Not being sure which forum would be the most apporpriate I elected to post the question here in General Discussion. However if the moderators have no objections I'll ask in the Smitty and Reloading forums to join into the dicussion here to address the points raised by Paul and Long Path.

I too think it would make an interesting addtion to the Desert Eagle line, much like the dual caliber .400 CorBon/.45 ACP combination being used in other autos.

For anyne interested the cost to have a chamber reamed to this caliber is $15 making the over all cost of converting a revolver $75. Reloading dies are available for $95.

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Gunslinger

We live in a time in which attitudes and deeds once respected as courageous and honorable are now scorned as being antiquated and subversive.



[This message has been edited by Gunslinger (edited June 22, 1999).]
 
I got some preliminary ballistic results today. They were achieved using an Ohler computerized chronograph. The charts were at the printer so the person was only able to give me limited info but will send full results by mail.

Using a 6" revolver with what was described as "tight" cylinder gap with a load of 170 gr. bullet, backed by 30 gr. of Win. 296 results were:

Muzzle velocity 2150 fps !!!

Energy @ 100 YARDS 1175 ft. pds.

These do bear out that the ballistics for the necked (wildcat) cartridge is superior to both the traditonal straight cased .41 and .44 magnums. Hmmmmm. But I'm still scrathing my head. :)
I'll post full ballistics upon receiving them.

Moderators this is taking a decided Handloading & Reloading slant and I will be happy to move it if need be. However the over all original question still doesn't exactly fit in any other catagory.

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Gunslinger

We live in a time in which attitudes and deeds once respected as courageous and honorable are now scorned as being antiquated and subversive.
 
2150 fps!!???? From a 6"???? I'm impressed. But wait! You're cheatin', and using a 170grainer! I want to see what it gets with the 210 grain bullets.

Sounds like an honest-to-gawd 100yd deer-huntin' pistol, if you can hold that tight. What kind of groups at 25 yds?
 
I asked about the 210 gr. ballistics and he assured me they would be included in the full report he is mailing. The 170 is cheating. Nothing more then an over grown .357 in my opinion.

He claimed six shot 50 YARD! groups of under and inch! The info in the mail may include 100 yard groups.

The .41 mag., my favorite handgun cartridge, is known for its "flat" tradjectory. With luck this round will retain those characteristics while at the same time dramatically increasing the effective range.
I'm going to try to lure Anthony into this thread. It sounds like he is the all time .41 mag. guru and president of the fan club. ;)

My second reason for starting this thread was to solicit in put into the concept weapon over all. To date this cartridge has not been chambered a revolver. So in addition to trying to learn the dynamics I was/am seeking others impressions of such a project.

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Gunslinger

We live in a time in which attitudes and deeds once respected as courageous and honorable are now scorned as being antiquated and subversive.
 
I'd be concerned about pressure. Seems to me that this baby would have a pressure pulse like you wouldn't believe. Were there any indications of excessive pressure shown on the cases and primers? Flattened primers, shiney rings near the base of the shell? I wonder if there is a "at home" method of getting those figures which is not only fairly accurate, (I'd think that +\- 100 C.U.P or PSI would be just fine) but also affordable. I'd hate to scatter my favorite wheel gun AND various parts of my anatomy over the range at a miscalculation of the pressure... Let us know!
Unkel Gilbey
 
Gunslinger,

Borrow or Buy a copy of Cartridges of the World. There have been several commercial and wildcat loadings of shouldered cases for pistols.

The .22JET had a shoulder that was too long of a slope, which is great for feeding in an autoloader (e.g. the M43 Bloc ctg - 7.62x39 and its predecessor, the 8mm Kurz for the STG-43/44) and aiding in extraction by the rearward forces. Unfortunately, as indicated above, this tendency to self-extract from the cylinder cause a binding with the frame in revolvers. It was not an issue in the few TC Contenders chambered for it.

The .357/Bain & Davis was a .357 bullet in a necked down .44MAG case. It was commercially produced by Ruger as a Blackhawk. Wildcat variations used a 9mm (.355 cal) bullet. The current .357SIG is essentially a necked down .45acp case. Some of the Action Express cartridges are necked down variants. The cartridge history is repleat with such examples of large diameter cases necked down.

Case shoulders do two things. It changes the headspace from the case mouth (which changes with case stretch in the case of semi-auto cartridges) to headspace on a median datum line on the shoulder (halfway between the beginning of the shoulder on the case wall and the base of the "neck" portion. This tends to decrease the variability from case to case for reloads, presuming the neck does not extend into the leade and bind the bullet release.

The other thing the shoulder does is create a higher speed mass velocity of the expanding gases, while concurrently increasing the slope of the pressure curve. Increasing the slope of the pressure increases the thermodynamic efficiency of the powder burn in the case, allowing the use of slower burning powders, that in turn reduces the peak pressure and will burn longer so that a wider pressure curve will result in continuing to accelerate the bullet out of a longer barrel.

There are some complex physical relationships to the bore diameter, the bore length, case volume, powder mass, primer brisance (sp?) and the powder burn rate, all of which affect the shape of the pressure curve, acceleration of the bullet and harmonic waves imparted to the barrel. This is great for rifles, but here-to-fore has not been effectively applied to handguns, until the advent of the .22BOZ cartridge.

I used to love the .357Herrett (.357 bullet in a cut-down .30-30 rifle case) back in the mid '70s. But technology for scopes and mounts hadn't caught up to the demands of the Wildcatters' cartridges and guns. So, I always shot verticle strings as the metal in the scope and mounts (best available then) stretched and eventully failed from the massive recoil of the TC Contender in that caliber. And those were only the reduced case-forming loads! After a year or two of buying new mounts and scopes after each range session, I gave it up & sold the gun. Shortly thereafter, TC came out with the super strong custom scope mount & scopes for the Contender... by then I'd moved on to a fascination with the new IPSC competition and "black" guns. The rest is ancient history.

Have fun wildcatting, but be aware that you can save yourself a lot of startup time by doing some research into the previous works.


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Mykl
~~~~~
"If you really want to know what's going on;
then, you have to follow the money trail."
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
 
Hey Gunslinger,

Sorry I'm late to the party. Thanks for the invite...

The concept has me salivating! Two of my three .41 Magnums are away with Ron Powers at the moment getting slicked up. So I am left with my S&W M-657 three incher for now.

What is the SAMMI figure on this new wildcat?

Is it within the specs that the N-frame can handle?

It would be a very revolting development to have a wonderful new cartridge, but a rattling 657 after a few rounds. If the 657 will take it, the concept is awesome. The unfluted cylinder would negate the problem of distinguishing between the two cylinders. The end result would truly be a multifaceted firearm to cover any need that I can forsee.

The load I'd love to test is using CCI's new 180-grain Gold Dot hollowpoint pushed to around 2000 fps. The Gold Dot is designed to stay together underextreme velocities and this is certainly extreme. It also seems to be quite an accurate design.

Other ideas might be the Kaswer Pin and Law Grabber bullets. These closely simulate the general profile advocated by NYPD Stakeout Squad vet Jim Cirillo (SWC instead of a WC). They come in both 170 and 210-grain.

Gunslinger: If you don't mind my asking, what gunsmith are you using on this project? Has he done any work with this wildcat before or is this a first model? Does he feel the 657 can take a fairly steady diet of the stuff?

We need to come up with a name for this little beast!

Something like...

.41 Magnum...with a twist
.410-.429
.41 SPLAT
.41 Turbo
.41 Countersniper
.41 Gunslinger (thought you'd like this one)
.41 Wunder Thunder
.41 FOOM
.41 Lone Star (I'm from Texas...sorry)
.41 Maniac
.41 Deer Interdiction Special

Other ideas?

- Anthony
 
Now we're gettin' somewhere. :)

Unkel Gilbey initial test were conducted using Win. 296. Preasure using 30 grains was within exceptable levels. However 31 grains was "stretching the envelope".

Mykl you certainly answerred my "why" question big time.I printed the page to study your comments-seriously. That is exactly what I was asking. Now once I've reread it several times I'll feel like I've been to the mountain and learned from the great one. :D

Anthony, my God man how can you sleep at night with only *one* .41 magnum in the house? ;) I knew you'd like this conversation. Sorry it already has a name. .41 GNR.

Gary Reeder Custom Guns ( www.reedercustomguns.com ) of Arizona have done the development work on the cartridge. The initial testing has been completed and although it was developed for the T/C Contender they claim preasure would be exceptable in an "N" frame Smiths.

As I stated above when I spoke with Gary he didn't have the figures at hand and was quoting only what he could remember. Once I've actually received the charts hopefuly they will answer some of the questions that have been raised. I plan to use the very feed back I'm getting here to ask any questions that aren't explained in the charts.

As a side not there is a man in IL. that is modifying S&W .44's to except either full moon clips or be loaded in the conventional manner one cartridge at a time. Once this cylinder is rechambered it will receive that treatment as well.

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Gunslinger

We live in a time in which attitudes and deeds once respected as courageous and honorable are now scorned as being antiquated and subversive.
 
Gunslinger,

Thought this might help...

This morning I was talking with Ron Powers about my three revolvers that he's working on at the moment. As Ron has been working on Smith & Wesson revolvers for 42 years and has lots of background with bottleneck cased cartridges in wheelguns, I thought I'd get his opinion on the .41 GNR conversion you're doing.

Ron saw no problem with the entire concept, but suggested that it be limited to Ruger Blackhawk and Redhawk revolvers if a steady diet of the GNR's was going through the gun. While the S&W N-frame is strong enough to fire the .41 GNR safely, the design doesn't have the strength to handle a steady diet of the stuff.

With respect to the unfluted cylinder, he pointed out that while this does increase the strength of the weapon this is not the weakest point in the design. The problem points are the cylinder notch stops and the thickness of the rear wall of the cylinder.

Bottomline...firing the .41 GNR in the 657 is safe, but wear on the gun will be greatly accelerated.

Anything new?

- Anthony
 
As Gunslinger is taking a little time off, I thought I'd juice this thread up a bit as I am very interested in the concept.

After talking with my gunsmith, I've decided to haunt the gunshows for a Ruger Redhawk in .41 Magnum to customize and port for the .41 GNR.

What kind of defensive applications do you think the .41 GNR might have?

Essentially duplicating a rifle round, the .41 GNR must possess some serious terminal ballistics.

- Anthony
 
Sorry for the delay Anthony.

I got the rest of the ballistics figures.

220 gr. Sierra FPJ has a muzzel velocity of
2100 fps and energy of
2150 ft. lbs.

However there is a note that the cartridge generates twice the energy of a .44 mag. and a muzzel brake is strongly recommended. Based on this I agree with your gunsmith (which I made note of, thank you) that these rounds would destroy an S&W in pretty short order.
Now I'm thinking maybe Anaconda with a custom barrel. (Any opinions as to whether one of these would hold up?)

As to defensive use I'm having the same questions as you. (gratuitous boasting ahead) While an officer with Key West, FL. PD we were required to qualify on what was simply called a "speed course" consisting of sixty rounds fired from ranges of 1.5 feet to 15 yards. The emphasis was obviously on speed, shot to shot recovery and rapid reloads. The range master, my Lt., certified gun nut and .44 aficondo, was convinced that the course could not be shot successfully with full house .44 mag. loads. I shot a possible (300 points) every time out with both a 4" and 6" S&W model 29 using "hot" hand loads. But it was with serious effort and I know I could not have done it with anything even slightly hotter. Making me think that my scores, and possible survival on the street, with the .41 GNR would suffer. Therefore I too am curious regarding opinions as to whether this a practical load for a carry gun.

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Gunslinger

We live in a time in which attitudes and deeds once respected as courageous and honorable are now scorned as being antiquated and subversive.
 
Hi Gunslinger,

Nice to have you back. :)

Ron and I were discussing the muzzle break issue and we both though Magnaport's new Quadport using four trapezoidal vents instead of two might be the best route. I'm rather leary of porting, but Magnaport is still the best in my opinion. I've heard far to many horror stories about hybrid and other newer systems on autos. To me, porting is a revolver only issue and then only Magnaport if absolutely necessary.

My one ported handgun is my S&W M-657 with a three inch barrel. Prior to porting it I tried many different ways to make it easier to control in rapid fire. This included an expensive set of Herrett custom stocks that did not work out. In the end, standard Magnaporting eliminated the muzzle flip and Pachmayr Decelerators took the bite out of the rearward movement. The difference before and after porting was phenomenal!

Based on this experience, I envision a stainless steel Ruger Redhawk in .41 Magnum with the 5 1/2 inch barrel, Quadporting, dual cylinders (.41 Magnum and GNR), and a nice set of cushy Pachmayr Decelerators. If a full house GNR isn't controlable, try loading down until it is. I'd bet you'd still be far higher than you could get with a .41 Magnum. Given that the hotter the load the more energy is bled off to the four ports, it would seem that the hot GNR would keep the muzzle rise to a minimum. For me, this is the worst part of recoil. The straight back part of the recoil is easily cut down by the Pachmayrs.

Controlability under rapid fire can vary greatly. I'd be hardpressed to qualify with the Remington 170-grain .41 Magnums at 1420 fps. The powder they use yields a huge fireball and blast is horrendous. Now let me do the same thing with Federal 210-grain Hi-Shoks at 1300 fps...no problem. The quality control at Federal is phenominal and out of my unported four inch S&W Model 58 I received a slight flash with this load. Far less than many .45 ACPs I've tried. In fact, this is my general purpose load that I carry right now.

The Colt Anaconda should be strong enough, but I do not know anyone that has shot one extensively. Ruger Redhawks in .41 Magnum are around on the used market at good prices. The last one I saw was $300 and I didn't by it!!! :(

The Ruger Redhawk has an awesome reputation for durability, reliability, and accuracy. This is how I plan to proceed.

Off the subject slightly, I recently found out the Kaswer custom loads 170 and 210-grain versions of the Pin Grabber design in 0.410 diameter. This is the SAME bullet that the company uses for their Law Grabber line of defensive ammunition. It's just loaded hotter. It's also Jim Cirillo's fav load for bad guys per his latest book. Hmmmmmmmmmmmmmmmmmmmm.

CCI-Speer is also releasing a new Gold Dot in 180-grain weight. YUM! I see some serious street load possibilities here!

As I don't handload, I'm talking with Tim Gray (he's on TFL) at Gray Area Ammo about doing some near maximum defensive loads with 170-grain Pin Grabbers or 180-grain Gold Dots on top.

Whadya think of that?

Have a happy 4th of July.

- Anthony
 
I've been toying with the idea of an "expansion chamber" to help tame the recoil. My only experience with one was a friends 625 in .45ACP with a one inch expansion chamber that dramaticaly reduced rear "push" and muzzel flip. If I'm having a custom barrle built my supplier said he would do that for free.
On all my "N" frames I use my own finger groove grips in either walnut or gonclo alves.
You may talk me into the Redhawk. Prices are better and I'm pissed at Colts politics any way.
I like the loads. I do reload, but by my own admission I'm not worth a dang at it. I'll have to experiment with some of those noted. If you remeber the old Hatcher theory of relative stopping power gave a 10% "bonus" for a good bullet design. I reckon that bonus was to the shooter, not the one being shot at. ;)

Have you thought about round butting that model 58 and shortening the barrel to 2.5"'s? Add a set of slim custom finger groove grips and you've got one serious CCW gun. It would make the Lew Hortons look sad by comparison.

BTW. My mother, yes mother, has one of the LH 629's as her regular carry gun. The grip design actually makes it more controllable than any of my square 4" 29's.

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Gunslinger

We live in a time in which attitudes and deeds once respected as courageous and honorable are now scorned as being antiquated and subversive.
 
Hi Gunslinger,

I do not reload either, but have been trying to find one of these little custom shops that will do the ammo for me. Friend of mine conned me into buying an RCBS machine a few years ago swearing he's teach me. I quickly found out that he didn't know what he was doing. So I shelved the whole project where it remains today. The .41 GNR might be enough to make me dust that thing off though.

I stared long and hard at that Model 58 trying to decide what to do, but as it took me about ten years of gun show haunting to find one. Also, it has the most beautiful factory nickel finish. I'd have to strip the nickel before I did anything and that would be expensive. So I opted for one of Ron's full house action jobs, ball detent lock, chamfered and numbered cylinder mouths, and a polished out trigger and hammer. Sights are zeroed for 210-grain ammo so I'll stick with that for it.

Expansion chamber, eh? Kind of like Andy Cannon's "Street L" conversion to the 686. I've seen it, but never tried it. Sounds good though.

The Herrett stocks were wonderful, but for some reason they blew it on the first try. They blamed the sketch I sent in, but I think they goofed and used someone else's sketch. The second try was much better, but it didn't beat the Houge Monogrip or Pachmayr Decelerator for me. Everyone's hands are different though. I'm glad your mother found something that works for her. My mother won't go near a gun. Bought her a Spyderco Endura for Christmas...I'll work her up from there. ;)

Have you seen the new Taurus Model 415? It's a wee five shot .41 Magnum. Now I've never been a Taurus fan, but the one I held was NICE for a Taurus. Action wasn't bad at all, but no speedloaders though. Very tight. Looks like I'd just have to carry it as a backup to one of my other .41 Magnums. :)

Do you think an HKS speedloader for .44 Specials would work for .41 Magnum? I could always use a Bulldog speedloader as they're about the same size.

- Anthony
 
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