Uberti 73 in 44 Mag?

[Lastmohecken]

I has read that Uberti did come out with a 73 in 44 mag, but never seen one until I spotted one on Gunbroker.
Has anyone had first hand experience with one of these?

For years, I had always read that the 73 was not strong enough for the 44 mag. Did they re-engineer it a little bit to make it stronger, better steel, or did someone just reevaluate the strength of the 73 action? Just curious, as I find the idea attractive, as it should make the 73 a little more powerful for hunting purposes.

[Malamute]

I have no doubt they will not last as long using full power loads as a similar gun using lower pressure loads, but it should be safe or they wouldn't have put them on the market. What the actual service life is, I have no idea but am curious to know if/when that becomes apparent.

Edit: And yes, My first guess is they upgraded the steel grade and/or heat treat on the 44mag 73s.

[Nath]

This is an old argument.
My take on it is the bolt thrust is no greater than any other chambering because at peak pressure the case grips the chamber wall, so much so it seals the gasses.

N.

[M. M. Wright]

You've got it right Nath. Bolt thrust is probably less from the 44 magnum, (straight case) than the 44-40, (tapered case). P. O. Ackley has a chapter in his first book about an experiment he ran on a 94 in 30-30 AI. Backing the barrel out one thread at a time until he had to extend the firing pin. All that happened was the primers backed out. The case stayed in the chamber without the bolt being against it.

[missionary5155]

I understand the principle involved with the case gripping the chamber walls. But there still is thrust on the bolt. Depending on the cartridge more than others. But there still is thrust. If not why do all rifles have heavy locking lugs of some type ? Ever hear about a bolt that lifted hard after firing a round ? Ever read about locking lugs that cracked ? Frames that stretch ? Not trying to be difficult but facts are hard to work around. There is bolt thrust. It has been measured.

The 1873 rifles / carbines when given a steady dose of smokeless powder at pressures above what a case of 3f will produce it is an unfortunate fact that frames do stretch, pins do bend and toggles do crack.

The new rifles may be stronger... but the 44 Mag produces pressure 3x + what a case full of 3F. Wear factor sets in. Even with 105 high velocity tank ammo each round had a wear factor. After "x" amount of wear factor the rifled gun system had to be inspected to evaluate if it was safe to return to the range. I expect the new model 73's will hold together for awhile but wear factors will overcome a weak action system.

Personally... my 73's new or 100 years old will get a steady diet of low pressure ammo they were designed to digest. I think Mr. John Browning already understood the need for a better lock up system and happily gave us the model 1892.

[Griff]

I thought that I'd read somewhere that bolt thrust from a .44Mag is less than that from the .357Mag. Something to the effect that the larger diameter provided a reduction of bolt thrust... can't recall where I read that; but... I found this:


I'm still not sure that pressure is all transmitted into bolt thrust... as the above chart would have you believe... for there is a certain logic that demands some of the pressure generated is sidelined into case grip in the chamber.

[EdinCT]

I have asked this before and never got an answer, but if bolt thrust is such a issue how come we can shoot these rounds in a Colt single action or Ruger's without set back locking up the action?
Also if you read the history of the 1876 toggle link action the Northwest mounted police saw barrel burst failures and no mention of action failures.

[missionary5155]

It is the same story with the 73. Receivers did not "fail". But they do stretch. Pins bend and toggles crack. Then the action gets "crunchy" or stiff as you try to work it. Most people figure out something is very wrong.

[Lastmohecken]

Well, that's about what I thought, myself, and they are probably just fine, for standard 44 mag loads. I just might have to get one, and try it out, one of these days.

[missionary5155]

Take a look at a revolver in 44 mag that has fired countless full power loads. How come there is a mark on the rear receiver where the case head gets pushed into the frame ?
How come Contenders lock up with high pressure rounds if there is no bolt thrust ?
How come Ken Waters in his excellent loading books talks about bolt thrust ?
Pressure is exerted in all directions. But internal ballistics (huge books to wade through) is not a simple formula. All factors come into bare that change the forces involved which ever direction.
Gun designers generally look at the barrel / front receiver ring to be the weak link. No gun manufacturer wants to build the fire arm that purposely has the bolt / rear receiver as the weak link.
Fill a 7.62x39 case with C4. When it is detonated in an AK 47 the bolt will fly straight back even though it is not the weakest part. The barrel / receiver left the shooter milliseconds previously. But there is more than sufficient excess pressure left behind to rocket the bolt out of battery rearward.

[Leverluver]

I don't have a dog in the hunt as far as the 44mag chambering other than I don't want one. I do have a 357 Miroku and do push it up some (~20k) and I may even pay the piper for that some day. In any case, I wouldn't be depending on the chamber grip saving my bacon because it goes out the window with any left over oil in the chamber or lube on the case. Smart folks will make sure there are no errant lubricants and the uninformed folks won't but everyone eventually makes mistakes.

[claybob86]

Even if the case grips the chamber, wouldn't a significant force would still be acting rearward to stretch the case and apply force to the bolt?

[Nath]

There is some rear ward thrust when;
Peak pressure drops some.

This is variable by factors such as oil present or bullet lube residue etc.

Revolvers can't be compared in this debate, the whole cylinder shuttles back on firing!

If the case did not grip the chamber at PEAK pressure there would be major gas issues for the operator and a nightmare of a cleaning job!

N.

[buckeyeshooter]

Lets look at the other side of the coin. If I wanted to shoot a SASS class with smokless and did not allow a marlin. The 73 in 44 mag would make sense if I was using 44 mag vaqueros. I shoot 6 grains of unique and a 200 grain lead at 1120fps in the marlin and an average of 820 fps in a set of 4 5/8 and 5 1/2 inch vaqueros. If used properly, I think no problem.

[FWiedner]

The '73 toggle-link lock was never designed for pressures in the .44Mag range. I'm not sure that using better steels makes more than a small amount of difference. It's just a weak design.

It's a good looking firearm. Buy one if you think it's cool. Go ahead. Just buy it with your eyes open, and know that it's gonna wear.

[Griff]

Lets look at the other side of the coin. If I wanted to shoot a SASS class with smokless and did not allow a marlin. The 73 in 44 mag would make sense if I was using 44 mag vaqueros. I shoot 6 grains of unique and a 200 grain lead at 1120fps in the marlin and an average of 820 fps in a set of 4 5/8 and 5 1/2 inch vaqueros. If used properly, I think no problem.

44 Specials work just as well in that environment.