doublegunshop.com - home Forums General Discussion Classic & Custom Single Barreled Sporting Rifles @ doublegunshop.com How To Blow Up A High Wall

I have seen blown-up Ballards, low walls, Stevens, Win M70s, Springfield 1903s, Krags, a Sako, all sorts & models of Mausers, as well as many others. The Trinidad instructors had a small collection of remains of that nature and occasionally gave us background stories and opinions about the cause-&-effect, and 40 years of subsequent experience has provided further examples.

The Kelver anecdote is the first time I've ever heard of a Ruger actually being damaged and I'm certainly curious about the details, too bad they're not available. I would have said, and still am of the opinion, that the Ruger No 1 and the Rem 700 are 2 of the very strongest actions ever made.
Regards, Joe

Wish I could tell you more but that was twenty* some years ago and Gerald was very touchy on the subject. If memory is correct it was a small caliber such as .22 or 6mm.

* I just check my tapes (recordings) and my last visit there was 1984.

Dennis, could you tell us if this was a small shank barrel? I know Winchester made some quantity of Small shank barrel actions with the Octagon top during the first year of Manufacture. I have one that is serial #800. I bought it as a Woodchuck rifle in .222 Ramiongton caliber. Could not make shoot worth a damm. Unusual for .222. When I disassembled it I discovered just barely legible .22 Hornet under the forend and nearly buffed out of visibilty. I built a 30-30 out of it and then became aware of the inherent weakness of this combination and so have refraned from shooting it. Have recently come into a .22 WCF barrel with small shank and intend to fit it up to this action. Regards, FITZ.

FITZ, I have an 1896-vintage hi-wall with a small shank 28" #1 weight barrel in .38-40 WCF. I have never hot-rodded that round in it (why would one do that?) and assume that the combination is strong enough for any reasonable load in .38-40 (or .44-40--I've seen one chambered for that powerhouse, too). What do you think?

I assume that the weakness of your .30-30 in the small shank barrel is the same as the Martini Cadet--too thin a wall in the chamber area (threaded area)?

JD currently has my Highwall #383 for assessment, it's an octagon top, thinside, #1 barrel, small shank in 32WCF (32-20).

It's probably going to be left original but I gathered it could safely be rebarreled to 38-55.


1885 #383

Please consider this: the Martini Cadet barrel shank is 0.750" nominal OD and is considered to be perfectly safe with 30-30s and even 44 Magnums. So why would not a small-shank high wall (with a barrel shank considerably larger than the Cadet) be considered safe with the same loads?

Answer: the high wall is safer because of the larger shank, but it's necessary to use a barrel made of modern steel to take advantage of that extra strength. The blown-up high wall shown above had a failure mode that began with the barrel split at the 6:00 position; this failure of the hoop strength support then caused the receiver ring swelling that resulted in the top of the ring blowing off. If a barrel of modern steel had been used then it's barely possible that the ring would have been OK, much like the receivers that Buhmiller failed to blow up. I'm no physicist (or even a good mathematician any more) but I do know that the barrel shank hoop strength component is crucial to the action's ultimate yield limit. Most good gunsmiths have been trained to not cut their barrel threads to an oversize force fit, so that when the barrel shank swells/heats when fired then it doesn't crack the ring. There must be enough hoop strength and clearance in the threads to prevent this radial pressure from expanding the receiver ring beyond its limit, and obviously the old high wall barrel was too weak.
Regards, Joe

Have always assumed that a small shank hiwall would handle anything on the .30-30 case including full loads for Improved Zipper or Donaldson Wasp.

Joe, Your forensic analysis of the high wall failure has got me glued to these pages. Your comment "...Most good gunsmiths have been trained to not cut their barrel threads to an oversize force fit..." particularly caught my eye as I think there must be a broad range of opinion on the fit of the barrel/receiver threads. I worked at a shop years ago (almost 40 now) that it was deemed desirable to cut the threads to what was termed at the time, "Cincinnati fit", which was basically a course finished thread that resulted in significant resistance when screwing the barrel up to the receiver. Other smiths I had contact with at the time cut the threads so that barrel could be hand threaded, or the weight of the action wrench would turn the barrel without any additional force. These were mostly bolt guns. After reading your comment above, I believe the use of tight fitting threads was more of a time saving approach on barrel/caliber configurations that it was not considered critical. Would this issue be more critical on single shot actions than the bolt actions? Thank for the great insight on this subject. Terry

Thanks for your thanks, Terry, this stuff is fascinating to me and has always been that way. You may also be interested to read the 'Finding Out For Myself' articles in The Double Gun Journal about damascus barrels and their relative strength compared to fluid steel barrels.

I totally agree with your assessment of the oversize thread practice, and hope I never become guilty of that sort of thing. IMO the smith should be able to screw the barrel completely up to the shoulder by hand or at most with the weight of the wrench, if this isn't possible then something is wrong and one set of threads or the other needs chasing.

I see no difference between the various action generic types so far as thread engagement is concerned, the primary consideration in my mind would be the thickness & heat treatment of the barrel thread shank versus the thickness & heat treatment of the receiver ring.

All barrels will swell a certain amount when fired, the amount of movement depends upon the pressure applied to the chamber walls, the thickness of the shank and the steel's heat treatment. As long as the steel's yield point is not exceeded then the shank will return to its original dimension but in the meantime during the few milliseconds of peak pressure it may have swelled enough to crack the receiver ring if the fit is too tight or the ring is too brittle. Actually IMO this occurs far more frequently as a result of added expansion (due to heat buildup from continuous firing) than from the actual firing expansion alone.

I remember a few years ago a Sako blew with a factory load and the uproar was tremendous, as you can imagine when a respected maker's product has a catastrophic failure. The failure mode was similar to the subject high wall's in that an initial failure of the barrel wall then led to overexpansion of the receiver ring and the blowup. The pressure was normal for a factory load, the receiver was found to have no flaws and to be well within factory tensile strength parameters but yet the ring was blown off. How?

Because the normally-high-tensile-strength Sako barrel was found to have a longitudinal flaw that allowed it to expand beyond the hoop strength limit of the receiver ring, even though the chamber pressure was perfectly normal. Just as the low tensile strength of the high wall barrel allowed it to expand enough to actually split and then crack the receiver ring under the high pressure of the 32-40 overload. In both cases the beginning of the failure centered on the barrel's thread shank rather than any fault in the receiver itself, and if either barrel had been strong enough to resist splitting then their respective receivers would probably have survived undamaged. That's why I consider it so important to use modern high-pressure steel for any barrels chambered for high-pressure cartridges, especially in these old single shot actions that sometimes have smaller thread shanks.
Regards, Joe

It took me a while to get back here and I see there has been a bit of discussion. This post should confirm the suspicions of some of you, as the subject high wall has a 28-inch number 2 barrel with small shank. Serial number is 273, manufactured and shipped in January, 1886, according to the factory letter.