doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Pressure vs recoil in old guns

I think in his round about way he is telling us that he was wrong and that recoil is the culprit for wear on an otherwise well maintained double gun.

One thing that has been left out of the discussion is the wear on the pin and hook caused by the physical act of opening and closing the gun. It has always been my understanding of the things that the pin was harder than the hook, and that wear on the hook was usually the cause of any looseness. Over a period of decades, shooting thousands of rounds, under sometimes less than ideal conditions with poor lubrication, wear on a gun will happen. If a gun is lubed correctly and shot with the ammo it was untended to shoot it will outlast the shooter. Pick up a 100-year old Parker with some wear: generally the action will wobble. But I'll wager the thing digested many many rounds of Super-X before wear became apperent, along with being opened and slammed shut with each round shot. And I'll also bet the reason "modern" guns do not seem to exhibit the same issues is they have simply not been around long enough. That and modern metallurgy. My $.02.

eeb that is a valid point. I have a L C Smith Quality 2 10 gauge made during the first half of the second year of production (1887) that is still tight on face with no play in the hinge. From it's condition you can tell it was well cared for but there is now way to determine how much it was shot but with 1 1/4 ounce loads which it was designed for and my moderate pressure reloads I think it easily could last another 122 years.

eeb;
If you go back & read my first post on this subject you will find I mentioned that most loose guns were the result of "Wear".
All;
There are several things which need to be borne in mind. Shooting a gun does not "Wear" it loose. "If" a gun is "Shot Loose" it is the result of metal deformation, not Wear.
2nd thing that needs to be borne in mind is that wall thickness has absolutely no bearing upon the forces tending to bend the hinge pin, deform the hook or stretch, bend or crack the frame. Thus in the example of the .22LR in an insert bbl the walls of the inseret containing the radial pressure is what takes care of the bbl, it could be shot from a Barrel made of River Cane. This has no bearing upon the back thrust of the cartridge. In this case one of the major differences is simply the size of the case, thus greatly lessened area for the .22's pressure to push against. 20K psi time .035 SgIn (approx area of the internal .22LR case) = 700 lbs thrust (No account taken of case wall grip). 11K psi times .44 SqIn (approx area of 12ga hull internals) = 4,840 lbs thrust (same conditions). But you "Rightly Say" we are talking of two different loads of differing pressures inside the same hull. It now becomes a lot more complicated. Note carefully though that a lead crusher will not read as high a pressure as a piezo/electric crystal. If the brevity of the pressure cannot compress a "Lead" piston to what it would theoretically be compressed by the pressure read by the PE crystal, it also isn't going to bend the standing breech made of a steel forging to the extent it should theroetically do from that same pressure. The peak of the pressure curve from say Blue Dot powder will be a lot flater than the peak of a Red Dot load for instance. Thus if a load is fired using each powder @ 9K psi for instance the 9K would remain longer with the BD load than the RD one. More metal "Bending, Stretching, Flexing etc would thus occur.
Bottom Line still is if you want to determine which load is most apt to burst yuor chamber, compare the peak pressures. If you want to figure which load will stress the hinge joint, frame, bolts & Stock compare the "Momentum" of the loads. If you compare the recoil using identical wt of gun for all loads the same percentages will be obtained. I did not point this out in my earlier post, but is necessary to keep all on the same level.
Another thing that should be remembered is a lot of these older guns are not as weak as many give them credit for. In my 1913 Lefever catalog the following are all the heaviest loads given for various powders in 12ga with "1¼ Oz Shot"
Black - 3½ drams (Guns over 7lbs)(My 8lb gun with 2 5/8" chambers should qualify here, as no chamber lengths are listed)
Bulk Smokless - 3½ drams by measure
Infalliable - 28 grains (3½ DE)
Walsrode -34grains (3½ DE)
Nobel's Sporting Ballistite - 28grains (3½ DE)
Note these aren't Pussy-Cat loads, & while true they do not exceed 1¼ oz they are well in excess of the above mentioned 3-1 1/8oz load stated as the "Heaviest" load guns of this era were "Designed" for.
No gun wt limitations were given except for black. Apparently Lefever Engineers were not aware of the fact the gun would recoil less with the Black because it burned slower than these other non-progressive smokeless powders.

Miller - You did mention wear early in this thread, now that I look back. The load you mention from Lefever, 3.5 drams and 1 1/4 oz of shot is an a$$-kicking pigeon load, even in an 8lb gun. You're right, the old guns were built to take it and still can, within reason.

Unfortunately, all black powder was not equal--any more than all smokeless is equal. So you go back to the black powder days and you add a bit of mystery to the recoil energy of those guns. That is, unless you know the muzzle velocity in addition to the shot charge.

I'd also note that in 1913, SAAMI did not yet exist. (It dates from the mid-1920's.) And prior to SAAMI, in this country, proof and service pressures were not yet regulated and standardized. Once they were, and once we'd switched to smokeless as a propellant, the hottest load available for the 2 5/8" 12ga was--and I have to make a correction here (print is SMALL in my old Shooter's Bible!)--a 3 1/4 DE, 1 1/8 oz load. 1255 fps, which I find listed at the same recoil energy I quoted before: 22.7 ft/lbs. So you're still jumping the recoil 50% just to get to the then-hottest 2 3/4" 12ga, 3 3/4 DE, 1 1/4 oz (1330 fps) at 33 ft/lbs. Not to mention the current hottest 12ga loads, which deliver over double the recoil of the hottest 2 5/8" smokeless loads.

I don't think anyone is saying recoil is a benign force. Obviously, however, since both SAAMI and CIP set pressure standards (and not recoil standards), neither is pressure. Best for the safety and integrity of our vintage guns to stick to loads for which they were designed--AFTER the establishment of an organization in which arms and ammo makers voluntarily cooperated to set standards. Better than talking about what Davey Crockett shot in Old Betsy.

At worst, recoil may bruise, or in the case of magnum rifle, detach the retinal laminae. Fragmentation grenades play hell with hands, eyes, brains. You can buy another gun but new fingers, eyes, forebrains aren't readily available. The proof houses and standards institutes are proving guns and setting operational limits for chamber pressure because they are concerned with preventing the latter. Someone here is speculating, implying, planting subliminal suggestions that proof houses and standard institutes want to safeguard your gun against wear. Stop that!

jack

Larry implies that the posters are claiming that there are no loose American guns. We don't claim that at all. What we are claiming is that a quality American double, set up tight and lubricated, will not loosen on the hinge in a lifetime of shooting with reasonable loads. Obviously heavily used L.C. Smiths and Foxes are rarely found loose when closed. Parker singles are seldom found in a loosened condition after tens of thousands of rounds. In the early period of their manufacture, 1 1/4 ounce loads were commonly used on the trap field.

The problem, eightbore, is the definition of "a reasonable load" for the gun in question. Seems everyone is missing the very critical chronology issue to which I earlier made reference: SAAMI was not established until 1926. Therefore, prior to that time, there were NO COMMON STANDARDS for the proof of guns in this country; no common standards for the proof of ammunition, nor the establishment of service pressure ceilings. I submit that, therefore, there was no definition of "a reasonable load" for all shotguns being marketed in this country prior to that time.

In other words, what was "reasonable" for a Parker, Lefever, Elsie, or Fox would not necessarily have been reasonable for a Long Range Wonder bought down at Acme Hardware. Unfortunately, lacking both a national proofhouse or a voluntary organization of arms and ammo makers (that would be SAAMI), Great Grandpa George Sixpack had no way of knowing what he ought to be shooting in his new gun.

The creation of SAAMI came about at a very critical moment in the history of shotguns and shotshells in this country. In 1926, the new Super-X was just hitting the market. That shell was longer (2 3/4" vs 2 5/8") than the old standard 12ga chamber, and hotter than the then-standard 12ga loads. So . . . we start with the fact that there weren't even any common proof and service pressure standards for the old 2 5/8" guns and ammo; add to that a longer, hotter load. (Ithaca had even switched to a newer, stronger design for its doubles--the NID--to deal with the newer, hotter loads.) It's at that point that the arms and ammo makers get together and say "OK, this proof level and service pressure are reasonable for 2 5/8" 12ga guns; these higher levels for 2 3/4" guns."

Think of this somewhat like OSHA--which, in spite of all its stupid excesses, manages to keep some idiots from harming themselves every year. Same deal with SAAMI--with a somewhat lower level of excesses. What SAAMI had printed on 2 3/4" ammo boxes was "Don't use these shells in guns with Damascus barrels, or in guns with chambers shorter than 2 3/4". Overkill? Yes, to a certain degree. But their view was, better to err on the side of caution. Sure, we know that some Damascus guns will handle smokeless powder loads (at proper pressures), and 2 1/2" guns will handle 2 3/4" hulls (at proper pressures). But the kicker is that the higher proof and service pressure levels for 2 3/4" FACTORY loads meant that they were not appropriate, either in most Damascus guns or guns with short chambers (which had different and lower proof and service pressure levels). And we also have to remember that back then, there were quite a few cheap, imported guns (many with Damascus barrels) that could not take the same loads as a Parker, Elsie, or Lefever--much less the new, hotter 2 3/4" loads. Or could not take them without wearing out in a hurry, or maybe worse.

That puts us where we are today. Thanks to those SAAMI standards, we know that we can take any new American-made 12ga with chambers 2 3/4" or longer, and we can shoot any American factory 2 3/4" load in that gun. We have that level of confidence because we have standards. And that level of confidence means that Joe Sixpack in 2009 is one whole heck of a lot less likely to get himself into trouble by selecting inappropriate ammo than was Great Grampa George Sixpack back in 1909.

But it stilla means that those of us shooting shotguns handed down to us from Great Grampa George--such as 12's built with 2 5/8" chambers, well before WWII--ought to be fed a steady diet of FACTORY 2 3/4" shells that exceed the velocity and shot charge levels established as standard for those guns by SAAMI. As for pressure, we don't know whether specific FACTORY 2 3/4" shells exceed the service pressure ceiling established for 2 5/8" guns--but we do know that the current SAAMI service pressure ceiling for the 2 3/4" 12ga is higher than it was for the 2 5/8" 12ga. So there's a very good chance that current factory shells are also overpressure in old, short-chambered guns.

Summary: You can say "My Parker (Fox, Ithaca, Elsie) whatever with short chambers has digested x thousand modern, 2 3/4" shells, and it's as tight as when it was new"--which is great, but which is relevant only to YOUR SPECIFIC GUN. It's what's called "anecdotal data". Because the next guy's gun might shoot loose--whether due to pressure or recoil we can continue to debate, but regardless--after having undergone the same use. If you want to PROVE that your gun is good to go with any 2 3/4" shell now made in this country, here's how you do it: submit it for proof at 19,000 psi. If it passes, continue to blaze away. But unless you do that, reasonable caution would seem to dictate that you ought to use shells loaded to no greater pressure, velocity and shot charge than were available on the market AFTER SAAMI came into existence. Those standards are known. For the 12ga, it's particularly easy to reload within those standards. Or you can buy shells loaded within those standards.

Unless someone has particular questions on this subject, that's where I stand.

Larry,

I have some questions, if you don't mind...