1873 toggle action

[joeng]

Hi
I'm the owner of an 1886 lever action, and was comparing its action to the 1873. Very different, of course. In the 86 the two locking bolts fit into the receiver mortises to lock the bolt.

In the 73 it seems as tho the bolt is held closed only by the force exerted by hand holding the lever, which fits into the base of the bolt. Is there any mechanical, metal on metal action that locks the bolt?

Thanks

[Pisgah]

Only the toggle action of the rear, articulated section of the bolt. It has nowhere near the strength of the '86, '92, or the '94. Supposedly, modern steels make this action acceptable for use with the .44 magnum. Call me a bit skeptical.

.https://www.youtube.com/watch?v=HNDRN_fjcDU

[AJMD429]

...what Pisgah said...

I'd like to have one in 32-20 though.

[vancelw]

...what Pisgah said...

I'd like to have one in 32-20 though.

I'm about to sell one to fund other, more expensive and less responsible purchases...

[M. M. Wright]

When the lever is closed on the 73, the links are aligned so the force from the bolt, (if there is any) is transferred to the rear of the frame with no downward thrust on the center pin. The ends of the links are fitted to the boss on the rear of the bolt, each other at the middle and the frame at the rear. If I were in the classroom I'd draw you some pictures on the board like I would have done during the 20 years I was teaching Mechanical Design to college students.

[Malamute]

Its been described above, but the simplest explanation is the link goes over center when closed, it not your hand that keeps it closed.

The weakness of the action in comparison is often mentioned in discussions about the toggle link actions, and the implication is they will blow up if some pressure boundary is slightly exceeded. Blowups are very rare in any lever action, and rarely the result of locking failures, more often of barrel failures. Keep in mind that Winchester tested the 1876 action with overloads, I dont recall the details, but they used a 45-75 whose factory load was a 350 gr bullet with 75 grains of powder. They used at least 2 if not more bullets, and double powder charges, it still functioned fine. They then removed one link and shot the excessive loads, and it then caused the action start operating roughly. They put the other link back in and it worked fine with regular loads. The primary issue as I understand it is they simply wear faster with heavier loads, and not that they blow up, but just get sloppy loose and can get to where they wont function well. I believe they can be rebuilt, oversize links are (or were) available, or could be custom made. Looking at it in the sense of what the ammo would cost to wear it out vs what it costs to fix, it isnt that huge of a deal to me. Same as AR barrels and bolts. They simply wear out or break parts (AR bolts sometimes break locking lugs off, and yes, they can still function). Repair as needed and continue on.

One friend that was involved in cowboy action shooting said he had an Uberti 73 in 45 Colt. He had about 50k rounds through it with no issues so far. He recently bought a Miroku Winchester 73 and loves it.

[Griff]

One friend that was involved in cowboy action shooting said he had an Uberti 73 in 45 Colt. He had about 50k rounds through it with no issues so far. He recently bought a Miroku Winchester 73 and loves it.

That would a low round count... for my 1986 production Uberti '73. And have had no problems with it, outside of an early extractor failure.

[Nath]

The toggle or any other firearm lock up does not contain the pressure, the cartridge does it. It is pressed against the chamber wall. That's why cases grow in length, because the case wall is being pressed that hard, the same pressing stops the case thrusting on the locking mechanism at peak pressure.

Can someone please find out how many injuries have occurred to users of toggle link designed firearms?
I am getting tired of all the internet jibba jabber against them!

N.

[Malamute]

I have heard second hand of one.

The oft repeated comments about toggle links runs along the lines of the bolt somehow blowing back out the back of the action into the shooters face or eye, which of course would be difficult if there was in fact a locking failure, as the bolt is much larger than the opening at the back where the firing pin extension comes out the back of the frame. The incident in question did somehow experience a catastrophic failure, the cause is unknown and unreported (or unremembered by me) when told to me (online), but the firing pin extension did come out and injure the shooter, though not fatally as is usually implied.

Most often in lever actions there is a barrel failure. The late 20th century version of the Marlin 45-70s is an example of that. The tests reported by Buck Elliot with the 454 Cassul in various actions had no catastrophic failures, regardless of the massive overload on the actions. All mainly became non-functional because of action distortion and stretch.

It may be possible to blow up a toggle link action, but its not from a minor or even somewhat major pressure limit infraction as is most often said outright or implied in online discussions. A double charge of pistol powder may do it, but I have doubts. A double bullet charge as has been found in progressive loader mishaps by people that are more concerned with how many rounds per hour they can load rather than paying attention to every step of the process may be able to wreck a toggle link action. Until someone is willing to destroy some guns to test various things of that sort, we wont know, but in average use, the actions are fine for their intended use, just as a 94 Winchester action is fine in the rounds made in and loaded within normal limits. It too can be wrecked or loosened up and worn out with overloads.

I for one, would welcome the chance to try to wear out a 73 type action in 357. I think the fun factor will be more than worth whatever it will cost to repair when needed. Im certain the ammo cost, even handloaded, will much exceed the cost to get it back in shape.

[earlmck]

Friend of mine got one of the new Henry rifles that Henry is making these days. We still don't know what did the dirty deed, but he got a waaay excess pressure load somehow in this 44-40. Probably double charge of Unique though Larry is such a careful reloader I don't see how. But it happened.

Case head separated when he tried to extract the case. Some drama involved in getting out a stuck case with the rim pulled off, but he got the job done. But such excess headspace afterwards that the firing pin didn't get a good dent in the primer and the extractor wouldn't go far enough forward to get over the rim when he tried to use the rifle.

Sent back to Henry and they fitted a new bolt and he is good to go again.

But when you exceed the elasticity limits of your brass case you do get dramatic bolt thrust and the toggle-link action can compress the bolt when this happens. Just in case anybody wants to know.

[COSteve]

Done

[gamekeeper]

Its been described above, but the simplest explanation is the link goes over center when closed, it not your hand that keeps it closed.

The weakness of the action in comparison is often mentioned in discussions about the toggle link actions, and the implication is they will blow up if some pressure boundary is slightly exceeded. Blowups are very rare in any lever action, and rarely the result of locking failures, more often of barrel failures. Keep in mind that Winchester tested the 1876 action with overloads, I dont recall the details, but they used a 45-75 whose factory load was a 350 gr bullet with 75 grains of powder. They used at least 2 if not more bullets, and double powder charges, it still functioned fine. They then removed one link and shot the excessive loads, and it then caused the action start operating roughly. They put the other link back in and it worked fine with regular loads. The primary issue as I understand it is they simply wear faster with heavier loads, and not that they blow up, but just get sloppy loose and can get to where they wont function well. I believe they can be rebuilt, oversize links are (or were) available, or could be custom made. Looking at it in the sense of what the ammo would cost to wear it out vs what it costs to fix, it isnt that huge of a deal to me. Same as AR barrels and bolts. They simply wear out or break parts (AR bolts sometimes break locking lugs off, and yes, they can still function). Repair as needed and continue on.

One friend that was involved in cowboy action shooting said he had an Uberti 73 in 45 Colt. He had about 50k rounds through it with no issues so far. He recently bought a Miroku Winchester 73 and loves it.

The Model 1876 is the only repeating rifle that had successful, documented use in the northern plains buffalo slaughter. Earlier repeating rifles such as the Henry, Spencer, and Winchester Models of 1866 and 1873 may have seen limited use, but only the Model 1876 was considered by hunters as powerful enough to do the job against the big woolies. The strength of the Model 1876 rifle and the .45-75 W.C.F. cartridge was tested by Winchester in the late 1870s. The factory conducted tests on the strength and reliability of the action to answer concerns by customers. These tests will astound collectors and shooters who have stated the Model 1876's toggle link action is "weak." In response to a letter sent to the company by Charles Hallock, Esquire, of Forest & Streammagazine, Oliver Winchester responded by telling about the tests the factory accomplished on the 1876 rifle. He indicated that engineers first started the tests by removing one of the toggle links and fired 20 rounds (this was with .45-75 W.C.F. cartridge with 350 grain bullet) with no effect. They restored the missing link then went through 6 more trials starting with a charge of 105 grains of black powder, behind a 700 grain bullet! The comment "worked well" is noted. They then increased the charge of powder to 165 grains behind 3 bullets (1,150 grains) and that "worked well." From there, they increased the powder charge to 203 grains and added more bullets until they reached 1,750 grains of lead (five 350 grain bullets). This also "worked well." Finally, they added one more bullet, bringing the total weight to 2,100 grains, and things began to happen. The comment was, "Breech pin slightly bent. Arm working stiff." The seventh and final test was again 203 grains of powder but this time six Martini bullets weighing 480 grains each (2,880 grains) were used. "The charge bent the breech pin, blew out the side plates, split the frame and otherwise disabled the arm," was the comment. Oliver Winchester noted that in this seventh trial, the shell had burst into fragments and the escape of gas at the breech did the damage.

[Nath]

There is a point when the brass thrusts the bolt....when pressure has dropped from peak pressure and any adhesive effect is lessened.
Smear marks from sliding/ejecting case in auto's is a mute point. The actions are designed to unlock at reduced from peak pressure stages so some residual pressure cycles the action, the case momentarily becomes a piston to cycle the unlocked mechanism.

Extreme pressure that causes a case head separation is the only circumstances when peak pressure is thrust on the locking mechanism. The fact the case body stays put in the chamber demonstrates the gripping effect perfectly!

No one is advocating over loading the capabilities of the brass and equally there is no need to down load from standards for the sake of a toggle link action.

It is very easy to assume/presume what goes on with high pressures. One often overlooked factor is time itself.
The time scale at peak pressure is so small there is no time for any yielding effects to the firearms themselves.

If one subjected some of the pressures used today in firearms statically and as a constant barrels would struggle to hold it and certainly a brass case head would let go. Time would allow the huge pressures to apply a moment of elasticity.

It never ceases to amaze me that toggle linked firearms are still made to this day and are also offered in magnum calibre's and yet folk ***** foot around them as though they are a fragile pocket watch.

You don't hear the same fears when it comes to luger enthusiasts! And there was a luger rifle!

All of saying is please don't hamstring a toggle linked gun from the get go, give the designer some credit and shoot them as intended.

N.

[coyote nose]

The toggles in the Winchesters I am almost sure actually come to rest a little OVER top dead center. That is, they come into alignment and then go a little past the alignment when the lever is fully closed. They are restrained from further movement past TDC by the machined cutouts in the top of the breech piston (as Winchester calls it) and the cutouts in the frame as well as, perhaps (?) the lever pin riding in the toggle slots. This keeps the lever from blowing open as the ends of the toggles try to contain the thrust of the bolt. We had 30 ton injection presses at work that were toggle operated...the links were a few feet long! Fascinating to watch. And I noticed they too came into alignment, then moved fractions past alignment to stop the same effect, of (plastic injection) forces causing the toggles to want to open.
The 'blow up' referred to in above posts occurred in a Model 1873 used at a competition back in 1998 I think. The guy didnt die, but he did have a firing pin embedded into the back of his right eye socket.
I shoot my 73s and 76s all the time, but I only use pyrodex. Just my 2 cents worth here.

[AJMD429]

"...They restored the missing link then went through 6 more trials starting with a charge of 105 grains of black powder, behind a 700 grain bullet! The comment "worked well" is noted. They then increased the charge of powder to 165 grains behind 3 bullets (1,150 grains) and that "worked well." From there, they increased the powder charge to 203 grains and added more bullets until they reached 1,750 grains of lead (five 350 grain bullets). This also "worked well." Finally, they added one more bullet, bringing the total weight to 2,100 grains, and things began to happen. The comment was, "Breech pin slightly bent. Arm working stiff." The seventh and final test was again 203 grains of powder but this time six Martini bullets weighing 480 grains each (2,880 grains) were used. "The charge bent the breech pin, blew out the side plates, split the frame and otherwise disabled the arm," was the comment...."

Wow....

I wouldn't expect any modern gun with modern steels to survive such a test. Seriously...would you expect even a Ruger No.1 to shoot overloads like that without damage....much less a bolt action, or semiauto. I suppose the semiauto would be extra vulnerable due to overwhelming the gas system or most other non-gas mechanisms, but still, I wouldn't dare load up my 92's or 94's or even my BHA-89 that hot.

Amazing.