Tom Roster's column in the latest Shooting Sportsman, titled "Worries" left me disappointed and wondering if someone else had written the column for him. I've been a long-time fan of Tom's writings and opinions but this one left me wondering. He starts off with the blanket statement that firing a 2-3/4" 12 ga. shell in a 2-1/2" chamber will cause "at least a 1500 psi" increase in pressure. Doesn't say how he determined this, though. It doesn't jibe with Sherman Bell's real testing, as we know. He goes on to state positively that this increase in pressure will automatically cause increased recoil. He doesn't say it increases velocity and I'm sure he doesn't know that, either. However, if the velocity doesn't increase, recoil will not. Pressure doesn't cause recoil and therefore can't increase it unless it also causes increased velocity. All but the most hard-headed among us knows that. I don't know if Tom ever looks in on this fine board but I am still a fan and still respect MOST of what he says. This one let me down.

"It doesn't jibe with Sherman Bell's real testing, as we know."

Yep, and Bell's writings doen't jive with the warning statements that reputable ammo makers put on their boxes... don't fire these shells in guns that aren't chambered for them.

All this long shell in short chamber stuff reminds me of the farmer who walked in back of his contrary mule 1000 times, no problem. Then one day the mule kicked him and broke his leg. Farmer says afterwards, gee, he never did that before.

Roster's column may have been edited, and the content spoiled or made to read poorly.
Roster normally talks sense.
There is a reason to not shoot cases longer than the chamber length.
I think there are more people heeding this advice than those following Sherman's theory.
'The other board' is well fired up debating Roster at the moment.

Dogfox, Bell doesn't say "Shoot 'em". He merely presents hard technical results of real pressure testing. He allows us to draw our own conclusions based on his test results. The "ammo makers" have never presented us with any test results beyond velocity figures. So, in reality, Bell's articles are not in conflict with the ammo companies preach, just a presentation of interesting information and research.

The majority of people are non-scientific sorts. They'll skim through an article, read a sentence here and there and make conclusions from limited data. Most also want to hear what they already believe right or wrong. Check out the comments, in effect that Roster is screwed up, on a few of the gun web sites.

It never ceases to amaze me. The big cartridge companies put warnings on the box not to shoot the shells if your gun isn't chambered for them. But people with nothing more than a high school education or maybe a liberal arts degree think they know more than the ballisticians and engineers at Winchester, Federal, etc. As far as sharing test results yesterday I used some muriatic acid to clean up masonry. The bottle had a warning on it not to spill on the skin, consume it, etc. No test results were shown by the supplier. Do you think I should heed the warning, make my own conclusions, or blow it off?

Bell does give extensive test results in his articles but I don't know if they follow an accepted scientific methodology, SAAMI procedures, etc. Until someone reconciles the different messages sent by Bell as compared with SAAMI, shell companies and Roster, I think I'll use caution and follow the latters' warnings.

Hi,
I don't disagree with either Jim or Dog, but don't think for 1 NY minute that the ballisticians & engineers at Winchester decide what warnings are listed on the box. It is the legal department trying to avoid any legal exdposure possible, it does not really matter if the facts show elevated risk or not.

Jeff G.

Yep. You are right. The legal department wants to avoid getting sued by dimwits who have not been warned about shooting long shells in short chambers.

What is the "other board"?

From a Peters 16 gauge shotgun shell box circa when they converted from roll to crimped shells (1950's ?). The situation back then was not like today when litigation is the norm.

'These shotgun shells MUST NOT BE USED in guns with chambers shorter than 2-3/4", guns with Damascus or Twist Steel barrels'

Hey guys. It isn't the Depression years when money was tight. You're not in a survival situation in the wilderness and you have to shoot whatever shell you have. Why not load or buy 2.5" shells if you have a short chamber? Why take the risk.

It is always a little amazing how impervious conventional wisdom is to even reasonably analytical work like Sherman's. I can't speak with much direct knowledge about the UK, but 2.5's are virtually unobtainable in Germany and Austria. Based on my experiences, I would suspect a third to a quarter of the guns on any given drive hunt are 67mm sxs's or drillings. They are all now, and have been for a generation, happily digesting 2 3/4 field loads. Don't even know a war story about one giving way.

Sure, it is "better" to use 2.5's in a 2.5 chamber, but the real thing to pay attention to is pressure and, hence, load.

Submitted for your consideration, and without editorial comment, by CC/dt

LC Smith

Too bad there ISN'T some editorial comment or pertinent facts included. Like if there was a 20 ga. shell dropped in ahead of the 12 ga. shell? Why it has an unfinished stock attached? Why the edges of the blow-out appear to have been painted gold? Some detail about what really happened? I don't believe is was a normal, properly loaded 2-3/4" cartridge, fired in a normal, healthy 2-1/2" chamber. Where's Paul Harvey when we need him? There has to be more to the story than a 2-3/4" shell in a 2-1/2"
chamber!
I'm not suggesting that anyone fire 2-3/4" shells in chambers shorter than 2-3/4". I don't give a rat's recoil pad what others do. Parker, in their own literature, said best performance would be obtained by firing 2-3/4" shells in 2-5/8" chambers, but what did Parker know? We've got people who worry about the wisdom of firing 2-3/4" shells in 3" chambers, fercrysake! Truth is, I lengthen my chambers to 2-3/4" because I can. Wall thickness permitting, of course.

Dogfox is 100% right.

I have to laugh at the way so many shooters flock to Sherman Bell as if he's the Second Coming.

I won't comment as to whether or not his 'findings' are ultimately valid or not - that's because I don't know. Neither does he.

I assume all the guys who take Bell's articles as hard fact have no background in mathematics, statistics, engineering, science, or production. 'Cuz if they did they would immediately spot that his work is meaningless as it ignores the basic rules of statistics and science.

I'd type more but I'm too busy; I'm in the process of writing a new set of rules for physics that will be very popular as they are a lot more forgiving than the current ones.

Just up from the Workshop...Feeding time for the Dirty-Hands Brigade!!Thanks to Dr.Drew for posting my Pic'I did'nt give himm all the 'Gen' on the Photo,, That one is of course is what was left of a 'Trap' LCSmith that had a 2.3/4" Re-Load that had had a DB load of shot stuffed into it for Indiana 'Turki' shootin' The Pic'I dont seem to be able to locate is 'Bloody Spectacular', Peter Nelson, Formerly of Purdeys Now 'Supremo Number 1 in the London Gun Trade(He is so Old now) sent me a photo of a 'Mint Condition Boss 12 bore c late 1930s,2.1/2"chamber, 1.1/8th oz Proof..it has just as much of the Breech Blown away!!!!If memory serves...A Spanish Chappie was Merrily stuffing 2.3/4" High-Brass Cartridges into the Breech for a 'Couple of Days'..Ducking in Spain...Costly"Error". I would think that if you have a Gun that is Chambered & Proofed for 2.1/2"x1.1/8oz and the weight is from 5,12, to 6.8oz...WHY shoot 2.3/4" I always like to see the look of Suprise on the face of a 'Shooter that has just Proofed their gun, and it 'Failed"....cc

Laughing is good for all of us. I don't take Sherman Bell as the "second coming" at all. I'm not sure I believe there was a "first coming". I DO however, give him a lot of credit for doing what the titles of his articles state: "Finding out for Myself". He's not simply a parrot, as most gun writers are, repeating "conventional wisdom" blindly, without ever testing anything for themselves. I'll be content to accept his findings, being just an ignorant mechanic, who spent my adult career making the creations of engineers, work.
BTW, "Conventional Wisdom" is not wisdom at all, it's on the same level as "old wives tales" and "urban legends". Often repeated BS is still BS.

I give him credit for experimenting - we all like to tinker. It's all the people who accept his results as fact that I question.

Here's the problem with Bell's research. He's using a sample group that is considered statistically insignificant. That's the death knell for any scientific 'fact'. Also, I haven't read his articles in a long time but I don't recall any of his means of measurement as being calibrated.

So, he's not measuring enough guns and he's using (probably) gauges and whatnot that may or may not be accurate.

Bell isn't blindly accepting conventional wisdom? If you are blindly accepting Bell's results then I guess I don't see the difference?

I put his articles in the 'interesting but anecdotal' column.

The picture posted by Revdocdrew, is also shown on page 89 of "Shotgun Technicana" and is, as David said, of an L. C. Smith that was blown up by a faulty reload containing a "double" load of shot? In any case, it has nothing to do with the topic of long shells in short chambers.

To further remind those who may need reminding, Sherman's conclusion was that firing a 2-3/4" shell in a 2-1/2" chamber, WHEN THE SHELL WAS OF A PRESSURE LEVEL THAT WOULD BE ACCEPTABLE IN THE GUN AT HAND, would not likely be danger. Firing shells producing much higher pressures than what would be appropriate for the gun at hand is of course, dangerous, but not because of the shorter chamber length. We all are reminded to keep pressures lower for our older guns, regardless of chamber match or mismatch. That is the really important thing, here. Be safe.
Lots of room between being reasonable/safe and being paranoid.

Dogfox and GregSY continue to parrot the 'conventional wisdom'.

The funny thing is that this 'wisdom' is backed up by nothing other than people/gunwriters/shooters repeating a lot of faulty information for 5+ decades.

I have a series of articles published in the American Rifleman in the 1930's during the establishment of the SAAMI standards. Many comments concerning chamber length, all saying it was basically irrelevant. PRESSURE is important and case length only if it has an affect on PRESSURE.

The reason for those warning on shell boxes is that with the establishment of SAMMI standards the service pressure for shotshells was increased dramatically compared to earlier shotshells.

GregSY, I don't think you are referring to the same Sherman Bell testing that the rest of us are. We are referring to the testing he did on the pressure readings of various lengths of shells in identified chambers. You are apparently referring to his articles on blowing up guns. That is not what is being discussed here.

As far as statistics go,how many samples does one need? A match factory wanted to sell very good matches. So,before a match could leave the factory, it had to light off. 100% test; no customers. Looking down the barrel of a loaded .357 and pulling the trigger generally only needs one sample to be significant. So, instead of saying statistics, how about mentioning degrees of freedom etc. and all that one wants before dismissing an experiment?

For a moment I'd like to see the discussion back off Bell and go back to Roster.

At the very least Roster appears guilty of some gross generalizations on a complex subject regarding the 1,500-psi pressure increase. I've no doubt he's fired a load as described that produces pressure spikes as described. But will all loads do this (as he implies)? There is evidence -- not just per Bell but Burrard, G Thomas and maybe even recent CIP proof-house tests -- that suggests this is not the case. Roster should present his evidence in detail and argue from that, also examining contrary evidence (Bell, etc.), before making blanket statements of this sort.

I find similar problems with his argument later in that column about shooting US-made loads in foriegn shotguns -- again, too many generalizations re a complex topic

Metalurgists: what say you to Roster's assertation that pressure increases from long shells in short chambers can result in "cumulative" ... "cracking of the chamber or the bore just forward of the chamber." Assuming, for the sake of argument, there are pressure spikes, does this in fact cause cumulative cracks in areas described?

Lastly, back to Bell: what format of ballistic tests (of the sort Bell does) would satisfy as to being statistically or scientifically valid?

Jim: thanks for the correction, and I have edited the posted pic.

Bell is only updating tests that have been done previously. Basically, his tests were a repeat of those the late British gun guru Gough Thomas had done for him by Eley Cartridge. In those tests, 2 3/4" Eley Grand Prix shells were fired in two test barrels. One was chambered 2 1/2", the other 2 3/4". (Bell and ballistician Tom Armbrust used the same barrel, starting with a 2 1/2" chamber and testing a number of loads, then lengthening just the forcing cone, and finally lengthening the chamber to 2 3/4".) Pressure readings were taken at 1" and 6" from the breech face. Pressure and velocity were virtually identical, whether the shells were fired in the 2 1/2" chambered barrel or the 2 3/4" chambered barrel. Note that the Eley shells in question were sold as being safe for use in guns with 2 1/2" chambers--JUST AS TODAY, BRITISH SHELLS FROM COMPANIES SUCH AS GAMEBORE AND MEASURING 67 OR 67.5MM, WHICH WHEN FIRED ARE EVERY BIT AS LONG AS SOME OF OUR AMERICAN 2 3/4" HULLS, ARE LIKEWISE NOTED--RIGHT ON THE BOX--AS BEING SAFE FOR USE IN GUNS WITH 2 1/2" CHAMBERS.

Thomas (who was an engineer by training) concluded, based on the Eley tests: " . . . if advantage is taken of the range of powders with different burning characteristics, nowadays available to cartridge loaders, to design a cartridge for use in chambers shorter than the case length, the extra length of case by itself constitutes no danger."

Roster was correct, in the last part of that column, to point out that American factory ammo most certainly should NOT be used in all foreign guns, even if the chamber is of the appropriate length. But that last section also raises the question of just which guns we need to worry about, because he did not further specify. Is there danger in using an American 2 3/4" shell in a new Beretta or Merkel or AyA with a 2 3/4" chamber? Most of us, I think, would say there is not. But there certainly IS such danger--again, regardless of the length of the factory chamber of the gun in question, and also regardless of whether the gun was made here or abroad--if the SAAMI service pressure of our factory loads exceeds the service pressure for which the gun in question was designed.

"GregSY, I don't think you are referring to the same Sherman Bell testing that the rest of us are. We are referring to the testing he did on the pressure readings of various lengths of shells in identified chambers. You are apparently referring to his articles on blowing up guns. That is not what is being discussed here. "

I stand corrected - I was referring to his articles on blowing up guns. I still would be interested in know how well calibrated and accurate his test equipment is, but I acknowledge it's far more likely to be valid in that setting. I'll bet the equipment used by the likes of Winchester cost in the multi-thousands range, and for a good reason(s).

Is Sherman's equipment adequately responsive to measure true peak pressures? A lot of the difference between expensive test equipment and cheaper stuff is the ability to consider rise time. In other words, the pressure may peak at a much higher level than he is reading, and drop off, before his device knows it happened. That could explain the difference between his readings and those made by the big guys.

Greg--You need to read the article in question. It's not "Sherman's equipment", but rather belongs to ballistician Tom Armbrust, who assisted Bell in his various tests. The specific article in question, "Long Shells in Short Chambers", is from Double Gun Journal, Winter 2001. Thomas' report on the Eley tests of long shells in short vs long chambers can be found in "Gough Thomas' Gun Book", pp 260-262, "Danger in Case Length". Note that those tests were done by Eley--like Winchester, an ammunition maker.

Tom Armbrust did the pressure tests in Bell's stories and Federal contracted his services for pressure testing when they were developing the 3.5-inch 12-g shell. The guy has cred.

As noted by GJZ, the equipment used is the same as the 'big guys'. Armbrust uses an industry standard pressure gun. Armbrust is the ballistician used by the 16ga group to test all of their loads. Pressure gathered by Armbrust and reported by Bell can be taken to the bank.

Ahrgh! Here we go again. How big of a sample size would you want? You've essentially eliminated any scientific argument because you will simply select a "sample size" larger than all the Damascus guns ever produced (or that owners are willing to part with, or that Mr. Bell and others are willing to spend to validate YOUR point)! Yes, you have to take the data with a grain of salt and not treat it as an absolute fact, but that MORE than you can say about what everyone one else says, which is NOTHING, except don't do it. Also, if you had read SOME of his material instead of SKIMMING through it, he clearly states when he uses Tom Armbust's pressure gun to calibrate against and when he doesn't. RTFM please!

The whole Damascus debate is useless to those who close their mind to the materials being used (iron and steel) as being inherently hazardous. Do you know another composite material that is commonly used, abused, taken for granted, and can fail catastrophically killing their owners, yet everyone buys them?!?!? Steel Belted Tires! (A rubber and steel composite, mind you). If you say, "But there's only 35 psi of stress in each tire", please hit yourself over the head with a set of Damascus barrels incessantly until I feel better.....

Mike Doerner - Mechanical Engineer (though I 'spose that's not good enough for this debate, since you'd probably want a Materials Engineer. Grrrr!)

Jim Legg, My apologies for my 'UP_COCK" this am....wish I had the time to dig out the "Blown Boss Breech" Photo....The unfinished stock that you noted from the photo of the LCSmith was an example that a Gent who had a "Copy Machine" (His term not mine) had built himself.......I gave him the Smith to see what he could do..Not quite good enough for the Trainee stockmakers That I was Guiding for the Veterans Administration Program for Disabled Combat 'Vets",Both WW2 (one) Viet Nam (Four)I had Double Amputees, and I was always looking for ways to take some of the "Grunt-Work" out of "My Trade" to help them master the ReStocking & ReForending of both shotguns & rifles.(This was done in 1984!)The Blown Breech Pic'was "HI-Lighted" to emphasize to the "Young,Upcoming Shotgun Shooters that I was guiding on the Trap&Skeet Fields....Do Not Under Any Circumstances use Somebody Else's Reloads....cc/dt

I'm still waiting to find out what "the other board" Salopian referred to, is. I'd like to read what others are saying about this month's column.
Thanks

Jim: here is another one:

http://bbs.shootingsportsman.com/viewtopic.php?f=2&t=36569

Before Sherman Bell; Before Gough Thomas; In the year 1938 the fold crimp shell was introduced to the British trade. Wadding had to be adjusted to get the same load in the "Nominal" 2½" shell (actually about 2 9/16"-2 5/8" long). The length of the loaded shell was much shortrned & there was Legitimate concern they would be mistaken for 2" shells which actually went to about 2 1/8", but of course loaded much lighter. Very shortly experimenting began on putting the same load with appropriate wadding in a nominal 2 3/4" case, which when closed with the fold crimp gave a "Loaded" shell length virtually identical to the roll crimped 2½" case. It was found that both pressure & velocity were for all practical purposes "Identical" between the "3" methods of loading (2½" RC, 2½" FC & 2 3/4" FC) all loaded with the same load. WWII prevented extensive testing at the time, but was continued immediately following. To the best of my knowledge from that point forward "ALL" British shells of a "Nominal 2½" length, closed with a fold crimp "Have been Longer than their Chambers". If you disagree give me proof.
All this was reported on by Burrard. Burrard did mention testing some few shells himself, but essentially reported the work of the British Shotshell industry. Previous to this he had warned against using 2 3/4" shells in 2½" chambers. This was two fold; First the longer "Roll Crimped" shell would actually enter the cone "Before Firing". There is a strong possibility of this delaying the opening of the crimp thus increasing chamber pressure. Second these shells carried a heavier, higher pressure load than the 2½" chambered gun was designed for.
Unfortunately both Thomas & Bell in their reporting honed in on statements Burrard made on using these heavier loads & totally ignored the actual facts of using appropriate loads in the longer "Fold Crimped" case. Bell was not even sure that Thomas' tests were conclusive & needed him to "Prove" them.
In point fact the matter was settled in 1938 & the "Billions" of British long hulled, fold crimped shells marked "For use in 2½" chambered guns" (paraphrased) should be sample enough.
To the best of my knowledge none of the current testers have addressed the question of using a shell which is actually long enough to enter the cone prior to being fired. Until such testing is done "Personally" I would strongly advise against doing so. One powder makers handbook stated that pressures could be varied very widely by simply changing crimp depth, thus strength. The hull being squeezed by the cone prior to firing has the effect of increasing crimp strength.
The testing which has showed no pressure concerns has all been done with shells having clearence prior to firing & the hull only laps into the cone after opening in a normal fashion. By this time the shot is already beginning to move, but without the space & speed to create an obstruction condition.

Miller, although Bell does not tell us in his article, I'm guessing that when he fired 3" magnum hulls in Armbrust's 2 1/2" pressure barrel, those unfired hulls likely extended into the cone. There was an increase of about 700 psi--from 10,953 to 11,665--from the 2 3/4" chamber to the 2 1/2" chamber using those 3" shells. But I agree with you that shoving an unfired shell into the cone is likely to be risky business.

As Mr. Bell points out there are always those who profess the "my mind is made up, don't confuse me with the facts" philosophy.

JC(AL)

Thank you, df. That's the one I wanted to read. I am happy to see there was some intelligent discussion over there. Some of it was "intelligenter" than some of ours. I'll add that "other board" to my favorites.
Thank you,

df - note that there are a number of people on this board that do have the background and inclination to read Mr. Bell's work, word for word, and to review his data and conclusions. His articles have stood the test of time. They are several years old and have been the core of many discussions, both here and off this board. If there was a fundamental error, it would have most likely been pointed out by now. However, if you think you see a scientific error, please point it out.

Mr. Roster's statement may be true for limited cases, but I've seen way too much credible data to accept his statement as the general case.

The shell manufacturers are stating a liability limiting warning that has a foundation of erring on the side of safety. They are correct to do so. But, once again, this is not a general statement for all situations; it is a warning for the shells in that box.

Larry;
The thing I noted about the 3" shells Bell fired in the 2½" chamber was first, they were low pressure reloads, at least in the article I read, maybe I missed another. As you noted he gave the pressure increase from a 2 3/4" chamber to a 2½" chamber. What he did not give us was an actual pressure when fired in a 3" chamber, thus we do not know how much actual pressure increase he had from the design chamber. In this aspect it all depends upon just how much the cone retards the opening of the crimp. As long as there is clearance between the end of the shell & the cone the crimp can open in a normal manner. Pressure rises "Very Rapidly" until the charge begins to move. It would not take much retardation in the opening of the crimp to prove disastrous. If there is any resistance with a shell chambering fully, "Yank it Out" & find out why. It may just not be fully resized, but if it is being jammed into the cone "Don't Shoot IT" is my advise.

Miller has reminded us of something brought up by an earlier poster (I think) who brought up some pressure figures involving loose versus tight crimps. The pressure differences between the two are more than we would have thought. Miller further mentioned the consequence (tighter crimps) of running a crimped shell into the forcing cone. I, personally, take Sherman Bell's testing only to the point he tested, in other words, 2 3/4" shells in 2 1/2" chambers. I'm not worried about putting 3" shells in 2 1/2" chambers because I'm just not going to do it. Let's face it, only about one in a hundred of us has a reloader set up for 3" shells and the factory shells are too off the scale for use in bird guns.

You're correct, Miller, in stating that Bell and Armbrust did not lengthen the chamber to 3" to get "normal" readings on the 3" reloads they tested. However, Bell did not describe the reloads as "low pressure". In fact, he described the lighter of the two as "too hot" for another test he had planned, and "scheduled for dismantling". The other one, even hotter, did come close to producing Roster's jump of 1500 psi--but that was when fired in a 2 1/2" chamber. I don't think any of us are nutty enough to shove a 3" shell into a short-chambered gun, at least not intentionally!

Larry;
Been awhile since I read that article. You are likely correct that "Low Pressure" was not really the right term. As I do recall though it was a lighter load than factory 3" "Magnum" loads, both as to shot weight & pressure. I also recall he strongly advised against intentionally firing one of them in a 2½" chambered gun, but tested it just to see what it would do "If" he accidently did fire one in the short chamber. Problem is it could only take one shell in which everything went "Just Wrong" & until far more testing has been done I will stick to my refusal of firing a loaded shell longer than the chamber. I do fire 2 3/4" low pressure loads in my nominal 2½" & 2 5/8" chambers.
It is well to note that Bell strongly recommended "Only" proper loads for the gun in question. Seems at least some are taking it he recommended firing any 2 3/4" shell which is definately not the case. I find no fault with the tests he carried out & applaud him for bringing to the attention of modern shooters. Just think he really should have stated he was "Re-Affirming" what had been proven 60-70 yrs ago, rather than leaving the impression he "Discovered" it, at least that was my take on it.