[41mag]

I was reading an article a while back about how Dick Casull worked up the loads for his .454.

I'm interested in the idea from a trivia aspect-I'm not planning on blowing up any of my guns.

Disclaimer disclaimed,does anyone have a lead-online or otherwise-on this type of info?

[Clark]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.


P.O. Ackley "Handbook for Shooters and Reloaders Vol I" 1962:
page 521: "..Dick Casull...Colt Frontier...5 shot cylinders..special [steel].. powder charges are introduced into the case in the order given... primer pockets altered..Remington 9 1/2 primers.."
454 Magnun, 230 gr, 2 gr Unique, 25 gr 2400, 3 gr Bullseye 2000 fps
250 gr 2 gr Unique, 25 gr 2400, 2 gr Unique 1890 fps
300 gr 25 gr 2400, 2 gr Unique 1710 fps

20" barrel Model 92 Winchester rifle:
230 gr, 2 gr Unique, 25 gr 2400, 3 gr Bullseye 2315 fps
250 gr 2 gr Unique, 25 gr 2400, 2 gr Unique 2185 fps

[HankB]

As I recall, Dick Casull's triplex loads required some care in assembly so that the powders wouldn't mix, but would be constrained into three distinct "layers." This required careful handling during the loading process and very high loading density, i.e., a heavily compressed load.

I don't recall ever seeing pressure test data for these loads, but Casull's guns could take just about anything thrown at them. I remember a test in one of the gun rags in which they filled a case with Bullseye powder, seated a 255 grain bullet, tied the revolver down, and fired it by means of a LONG string. The revolver actually held together! (Anyone who tries this while holding the revolver is an idiot!)

Elmer Keith tried "duplex" loads in rifle, but his didn't actually use two different powders - he used a modified case in which a tube carried the primer's flame to the front of the powder charge. He claimed to be able to get a couple of hundred feet per second of extra velocity with normal pressure, but the technique was supposedly dependent on having a tight chamber.

[Clark]

I think I have read that artillary duplex loads have a tube to get the flame to a spot behind the bullet.

I don't know this, but I suspect that the ball powders like H110/W296, LIL'GUN, and AA#9/Enforcer will beat the old 2400 based duplex loads in the velocity vs pressure contest.

[taliv]

i was planning to experiment with duplex loads in the spring with some sabots i'm working on. i'm not going to try them though, until i get a pressure gauge

[41mag]

let me know where you live and what day your are going to try the duplex loads. I would like to set up a remote camera and watch it from some distance away as in at least a100 yards. duplex and triplex loads are only for fools

Always appreciated,these helpful-encouraging replies. :rolleyes:

[grendelbane]

Clark, any theories as to the reason behind the loading sequence? The fast, slow, fast cocktail does not compute.

I would think that the primer igniting a charge of slow powder, for initial acceleration, with the fast powder igniting somewhere down the barrel, (hopefully), increasing the pressure farther down the barrel, without increasing the peak pressure, would be the way to go.

I am not going to attempt any experiments along this line, as I just realized I can not even write a decent sentence about the idea! :banghead:

There is quite a difference in speed between 2400 and Unique. Have any experiments been conducted with powders closer together? That might make it easier to keep the powder compressed.

I admit to an evil fascination with the subject. Still, I don't want to actually experiment along these lines. Life, (and reloading), are complicated enough as it is. :D

[taliv]

i'll preface this by saying i have absolutely no idea what i'm talking about and i'm totally talking out my ass here...

but i think the advantage to the duplex load is avoiding the pressure spike at the beginning while the bullet is still at rest (inertia and all) and the friction as it first squeezes into the lands.

i.e. what grendalbane says, start with a little slow powder and move to the high octane stuff.

i'd be pretty dang impressed if a handloader got the timing right to get a substantial gain from a triplex load, assuming there is even a sane underlying theory to a three-stage burn

[Clark]

My primitive armchair analysis says that what a duplex or triplex does NOT want to do is have the fast powder blow the slow powder out the muzzle before it ignites. So what they do NOT want to do is put 2 gr Bullseye right over the primer and the 2400 on top.

So that would mean the slow powder would go over the primer. and a tube might be used to get the primer flame up to the fast powder.

In 1962, when that book was written, if one wanted to load up the 454, what were the choices?

They could squeeze [110% density] 28 gr of 2400 into the 454 with 230 gr, and be up a 60 kpsi, with only 1800 fps. So maybe the triplex was to get three humps or non concurrent pressure peaks.

[grendelbane]

Another thing that you should not do is place a primer over the powder charge, and seat the bullet against it. Supposedly, the primary primer ignites the powder, which slams against the secondary primer, which ignites it, insuring that the powder charge is ignited both at the front and the back.

Not sure what results would actually occur if any one actually ever did this.

Perhaps we could develop a cone shaped spacer, (think witch's hat), and form the powder into a shaped charge. If there was a strong spring in the witch's hat, it could add a little boost to the velocity of the bullet. :D

[taliv]

heh, or even better, we could build a miniature trebuchet which could fling the faster burning powder down the barrel after the bullet

[HankB]

Another thing that you should not do is place a primer over the powder charge, and seat the bullet against it. Actually, this was a technique used by certain wildcatters in the post-WWII period. Component primers of the day weren't thought to be "hot" enough to properly ignite large charges of slow-burning powders in big express rifles. (In addition to wildcatters, some of this activity was also due to attempts to reload big British cartridges with conventional powder, rather than the original Cordite.)

Federal eventually introduced a very hot - for the time - magnum large rifle primer which put an end to these experiments.

As for triplex loads, IIRC the rationale was that a fast burning powder over the primer would help ignite the main charge (some black powder cartridge shooters still do this) and the charge of medium-burning powder right behind the bullet would act as a "booster" after the main charge was consumed. Since the bullet was thought to be down the barrel already, the effective volume was already increased and peak pressure was falling, so that was an opportune time for a little boost.

It would take modern piezo equipment to see whether or not this theory is valid . . . or is just so much hooey.

[Ross]

Recently, due to the unavailability of certain powders, Australians were occasionally mixing two powders to get an intermediate burning rate. The practice seems to have fallen into disuse as appropriate powders are now available.
Cheers from Darkest California,
Ross