Monday, September 14, 2009

The Eisenwerke push-lever lock: Is this an early version of the now-common breakbarrel?

by B.B. Pelletier

A funny thing happened to me Saturday evening. I had a gallbladder attack. I was up from 9 p.m. Saturday evening until 4 a.m. Sunday morning with severe nausea and extreme pain. At 4 a.m. Sunday, I finally went to the emergency room, where they told me I had gallstones. They wanted to schedule surgery immediately, but I declined and was discharged.

The point is that, had I stayed in the hospital for the operation and recovery, I wouldn't have been able to do a blog for a couple days. Edith would have posted blog reports from past works for a few days, but I just wanted you to know that I would have been out of touch for a day or two.

I'm fine now and am making dietary changes. Pretty much everybody has gallstones, so this isn't a big deal. Now that I know I have a gallbladder issue, I can deal with it.

More news
Paul Capello was kind enough to forward several photos from the next American Airgunner show, where we teach Crystal Ackley to shoot. I want to share them with you because of the high interest her shooting seems to have generated. We showed her how to operate several long guns safely so she can be a show host in the future. She was delighted to join our team, so you guys will be seeing her on the show for the rest of this season.


In the next episode, we invite Crystal to become a host on American Airgunner. Photo provided by Paul Capello.



Crystal likes the Benjamin Discovery for its size, light weight and accuracy. It suits her very well. This photo was taken from a later episode in which she learns how to shoot silhouette from Mike Sporer. Photo provided by Paul Capello.



Here she shoots Daisy's Avanti Champion 499 BB gun, billed as The World's Most Accurate BB Gun. If you can see the show, you'll see what a natural she is! Photo provided by Paul Capello.


In the episode Crystal Learns to Shoot, Paul and I introduced her to a number of long guns. If she's going to be a host on the show, she'll have to know the basics of safe gun handling, plus how to handle each specific gun we have. She's a fast learner, and I think she'll be up to speed in no time.

For all who have asked, we will be working on getting video segments from the show posted to the website next. The show production has to take priority, of course, but we know that many of you do not receive the Sportsman Channel and would like to be able to see some of it on the internet.

Now, on to today's report:

Here's a blast from the past. I wrote this article for Airgun Revue #5, which was published in 1999.


You never know what you'll find at a gun show. Sometimes, vintage airguns show up, such as this German specimen.


This grand old airgun surfaced at the 1999 Maryland Arms Collectors' show in Timonium, Maryland. It was made by the Eisenwerke factory in Gaggenau, Germany, and sold by Tower & Lyons of New York, whose trademark is roll-stamped on the top barrel flat. The name Columbia is also stamped on the barrel along with the word patent. The crossed pistols trademark of Eisenwerke are also present to tell us who made the gun, as there is no other clue anywhere on the outside.


The top flat of the barrel tells us who made the gun and who sold it. Tower & Lyons was a firearms retailer in New York at the turn of the century. The three different barrel cross sections can be seen here.


It was available at the show for a reasonable price, so I acquired it specifically to document for Airgun Revue #5. I've looked at these strange old breakbarrels, as I'm sure many of you have, and wondered just what sort of airguns they were. Were they like the Quackenbush push-barrel guns, or were they more like the buglespanner gallery guns from Europe? Or were they simply fragile copies of the earlier Pope and Bedford & Walker air pistols, grown to long gun size?

The gun--and it's a smoothbore, not a rifle--is 41.75" long and weighs 5.5 lbs. That puts it in the Diana model 27 category size-wise. It's finished two-tone--in bright nickel and deeply polished blue. The blue has turned about halfway to a plum brown, and the nickel, while quite prevalent on most surfaces, has gone satin from corrosion underneath.

The barrel is solid steel, 21.6875" long and bored smooth throughout. It's shaped in a square section at the breech, which transitions to an octagonal section a few inches forward, and then to completely round near the halfway point. You can tell by examination that this was not an easy barrel to make. Today, there would be shortcuts to save the costly machining operations it obviously required, but that's a great deal of its charm. It also serves to date the piece to a time when machines were capable of complex profiling, and labor had not yet become a big issue.

The breech face of the barrel is a straight cut on the square end of the barrel. When the barrel's closed, the flat breech is pushed against the front of the receiver through the action of the two link arms. The sides of the breech are cut on a taper from top to bottom, with the result that they're squeezed into position by corresponding shelves in the front of the receiver. A leather breech seal, now missing from its circular groove in the receiver, completes the air seal. In a moderately powered airgun, it does the job rather nicely, with no air loss during shooting.

The trigger is a very simple latch that just gets out of the piston's way upon firing. Because the gun is so moderately powered, it can have a light, crisp action without a lot of complexity.

The stock is a nice piece of dark hardwood that could be walnut and is checkered at the wrist with 14 l.p.i. flat diamonds. The low cheekpiece and schnabel are quite fitting for a gun from around the turn of the century. Unfortunately, someone in the past saw fit to slather Tru-Oil all over the wood, which now gives a rather cheap appearance; but it probably preserved the wood underneath. Removal would reveal some very nice grain.

The heavy iron Swiss buttplate has no visible traces of nickel remaining, making me wonder if it was ever plated to begin with. It seems massive compared to the rest of the gun, but no doubt it's in keeping with the style of German guns at the turn of the century.


Here you see the unusual arrangement of the cocking mechanism. The rod connected to the underside of the barrel pushes directly on the head of the piston to cock the gun. Although the Champion air pistol used a similar arrangement, it didn't use the barrel for leverage, which is what makes this such a powerful design. It's an interesting offshoot of the modern breakbarrel airgun.


The most unusual part of this gun is the way it cocks. It's a breakbarrel, but the mechanism is earlier than what is seen today. The barrel itself pushes directly on the end of the piston through a bar pivoted under the breech. There's no baseblock. Instead, the barrel is held captive by two flat bars connected to the action and by the piston rod. The hermetic seal at the breech is the result of a direct seal between the barrel and the mainspring tube. If you study the cocked gun, you'll see this strange arrangement. This is termed a hebelscheiber verschluss or push-lever lock, as the rod connected to the barrel pushes directly on the face of the piston. According to the writings of Larry Hannusch, push-lever locks are not common. They were made by only very few makers.

In the book Gas, Air and Spring Guns of the World, a gun very close to this design is shown in an extracted drawing from an advertisement (p. 76). Author W.H.B. Smith says the design was completed around 1905 but never met with commercial success.

I think the truth probably lies closer to what Hannusch says than Smith. The basis for that belief is that we have a specimen of a gun in hand with commercial markings. Tower & Lyons bought this from the German manufacturer and had their name put on for resale, just as is done today. Either this gun is one of a small sample sent to T&L for evaluation, a not-uncommon event, or else it's one of a lot of guns they bought and resold. Usually, samples are not this complete. They come with other things on them, and the buyer understands that these minor items will be corrected in the first shipment of production guns. That's not always the case, but it's probably the norm. So, if T&L were selling this gun, it had to exist in some numbers.

Also, the gun carries a four-digit serial number. By itself, that doesn't mean much, because we know of makers starting production at high numbers to create the impression of high production; but when viewed in light of this particular gun's very mature appearance, it seems correct.

Of course, we can conjecture till the cows come home, and nobody will be the wiser. Whatever the truth is, this is a rare airgun.


The rear sight slides straight back, allowing the barrel to tip up for cocking.


The rear sight is fixed as far as adjustments are concerned, but it also functions as a sliding latch to hold the barrel shut. By sliding it backwards with a finger, the barrel is freed to tip up at the breech. It's a novel arrangement and the only one like it that I've seen.

The front sight is a typical post and bead, mounted on a dovetail across the barrel. Windage can be adjusted by sliding this sight sideways in its dovetail opposite the direction in which you want to move the projectile.

Overall, this is a fine, collectible airgun. There's a chip in the schnable, and of course the Tru-Oil on the stock, but these are minor problems in a rare piece like this.

On the down side, a former owner saw fit to engrave his Social Security number on the underside of the receiver, and the name J. Weber has been engraved on the side. Both were done with a modern vibrating tool, so they probably date from the 1960s or later. Unlike the Tru-Oil on the stock, the engraving is more permanent, and very difficult to remove. A useful practice for bicycles and boat motors, but one that removes value from fine collectibles like this one. A person wouldn't do it to their silver tea service or their pre-'64 Winchester, so why do it to an airgun that's even rarer? Today, we can only smile and pretend that it adds charm to the piece, which it no doubt does in many minds.

Elsewhere on the gun, the last two digits of the serial number are found everywhere. It was made in a time when parts were married together at the factory and meant to stay that way throughout their life. Happily, all numbers match.

What about power? This gun is a .22, which is not a common caliber for European airguns of this time. Was it a magnum blaster or a pussycat? Well, the years have robbed the mainspring of much of its power (who hasn't been through that?). Today, the gun barely launches darts at just below 200 f.p.s. Pellets don't even come out of the barrel. But its construction suggests that it was at least as powerful as the best Quackenbush or Gem in its day--if not more so. A fresh spring and perhaps a new leather head on the piston (if it has one) would probably do wonders. I wouldn't be surprised to see 400 f.p.s. from a well-maintained gun.

That's actually not too far from the mark. The larger, more powerful BSA underlever, first made in 1906, was fully capable of achieving 600 f.p.s. in .22 caliber when it was new. This gun has a smaller powerplant than the BSA, so the lower number seems appropriate, if even a bit conservative.

Alas, the gun is now gone. Another collector is enjoying it, but we had the privilege of examining it closely for awhile. Sometimes, that's enough.

52 Comments:

At September 14, 2009 6:20 AM, Blogger Buck said...

B.B.

Sorry to hear about your gallstones. Sounds like you need a vacation. We wish you all the best. And take it easy, post all the old blogs you'd like if you need to rest. Any of the "Remembering when" stories would awesome.

 
At September 14, 2009 8:33 AM, Anonymous Anonymous said...

B.B.,

From all of us that enjoy your blogs...

If it is the blog or you health, it is no contest. Your health comes first. We can miss some blogs.

 
At September 14, 2009 8:46 AM, Blogger kevin said...

Really looking forward to seeing the video segments from the show when they get posted on the internet.

What a gem of an air gun. Very interesting. Sure is a lot going on in that little package. The bsa's you mentioned from the same era seem plentiful in numbers and simplistic in design when compared to the Eisenwerke.

kevin

 
At September 14, 2009 9:59 AM, Anonymous twotalon said...

B.B.

Hope they can get those stones fixed for you. Heard that they are miserable.

twotalon

 
At September 14, 2009 10:10 AM, Anonymous Anonymous said...

b.b., or anyone. Whilst cleaning out a friends garage this past weekend we found something he had completely forgot.
A Crosman Model 1861 Shiloh. It's like new, in the box. We loaded a CO2 cartridge (oiled of course) and the seal holds.
Is is worth anything...and is it a descent shooter?
CowBoyStar Dad

 
At September 14, 2009 10:40 AM, Blogger FRED said...

CowboySD - if no one else gets back to you on the Shiloh, I'll respond this evening. I'm at work today (sometimes I have to show up here) and do not have access to my Bluebook.

Wishes for a speedy recovery to you, BB. I'm sure Edith will have a surefire cure just waiting for you :)

Fred

 
At September 14, 2009 10:55 AM, Blogger kevin said...

CowBoyStar Dad,

According to the current blue book the Crosman Model 1861 Shiloh is BB/.175, .177 cal., CO2, one Powerlet, SA revolver, patterned after US Civil War Remington cap and ball revolver, 370 fps, 1.9 lbs., Mfg. 1981-1983. In 100% condition is worth $75.00 and add 20% for factory box.

Is it a decent shooter?

kevin

 
At September 14, 2009 11:23 AM, Anonymous Anonymous said...

Thanks Kevin.
As for it's shooting ability we didn't really try it extensivley.
I'd image it to be a so-so shooter. It says it will fire either pellets (.177) or B.B.s, so I imagine the barrel lacks rifling.
But if it has a decent reliabilty record I'm thinking of offering some cash for it and it can join the kids armoury ;-)
CowBoyStar Dad

 
At September 14, 2009 11:26 AM, Anonymous Mr B. said...

Good afternoon Edith,

Sorry to hear that your hubby has gall stones. However, we know that his recovery is in good hands--yours and that your are working hard on getting him well.

Mr B.

 
At September 14, 2009 11:35 AM, Blogger B.B. Pelletier said...

CSD,

The Crosman Shiloh is a cowboy-looking revolver that has not increased in value the same as other Crosman guns like the Single-Action Six. I think it is undervalued at the price Kevin quoted, but I have to be honest--they sell for that at the shows.

I think it would be a nice addition, if you could get it for about CSD$80 or less.

B.B.

 
At September 14, 2009 11:51 AM, Anonymous Anonymous said...

BB

I wouldn't call severe nausea and extreme pain a funny thing. You have to take care of yourself first man, you're the sport's best friend in America. A blog from Edith would be delightful, plus there is plenty on the archives to keep us all occupied for a while.

Unless Crosman is selling Marauders for half price for a limited time. Then you better shake a leg and make a post to let me know about it pronto, I don't care what's wrong.

To everyone else: try and stay on hazenadog's good side. He doesn't appear to cut any slack!

SlingingLead in Powder Springs

 
At September 14, 2009 11:56 AM, Anonymous FrankB said...

What a funny coincidence...This past saturday at the local flea mkt.,an old friend and vendor gave me a pistol to evaluate.it was a poor example of that Shiloh.sadly,it wouldn't hold co2,and the advancement pawl wouldn't engage the cylinder without coaxing...I told him the condition made it not worth messing with.the owner wanted 50$,so a quick number crunch tells me I didn't steer him wrong.

 
At September 14, 2009 12:00 PM, Anonymous FrankB said...

P.S.GET WELL BB! EDITH NEEDS YOU,AND SO DO WE...

 
At September 14, 2009 12:39 PM, Anonymous Anonymous said...

B.B.

Sorry to hear about the gallstones. Don't let the blog interfere with your health. Hopefully, Edith with have a magic cure for you.

I see that Crystal has the right elbow up halfway. Is this part of being natural or was it coached? My arm has migrated up to about the same position. Where is Crystal's ear protection or that of the guy in the background--is it Mike?

I was thinking that I hope Crystal does not walk away from the shooting as a curiosity as some other fine female shooters described over the weekend. I was training some acting students in fencing and falling techniques, and they loved it. Apparently there is not a reliable source for things like this, and actors just pick it up wherever they can. As a librarian, I can say that sources of good, organized information are relatively few. She should learn everything she can from you guys so that she can be another Lara Croft or director of one.

A belated thank you for the fine pistol shooting video--especially amidst your busy schedule. It's all Herb and Jane's fault for getting me into this scientific stuff.... :-) The circle is closed from when you first mentioned LTC Bonsall years ago and had me wondering about the technique. It overlaps somewhat with the Bill Wilson video I got. Wilson says apply pressure on the grip forwards and backwards--not sideways--and squeeze as hard as you can without shaking. What kind of pressure do you apply with the middle finger?

My 1911 shooting is coming along but has a ways to go. At 7 yards, I was shooting about 6 inches below point of aim which is just the same as before. But before I had the sights on maximum elevation and this time they were on minimum elevation, so I'm making progress. Groups were barely recognizable although this may have been due to a yank factor where I was pulling the bullet up onto the target. The push moves on. Thanks.

BG_Farmer, I hadn't really considered the effect of pellet drag on its orientation since I had supposed that drag just acts opposite to whatever is causing it and would not cause any change in direction. I don't know.

Herb, thanks, but I feel satisfied with my answer to the question and am done with statistics for the time being.

Matt61

 
At September 14, 2009 12:47 PM, Blogger B.B. Pelletier said...

Matt,

We coached Crystal on her stance, but not where she holds her arm. She gets into what I would call a classic stance and then waits to hear the corrections we offer. It's like trying to tell Secretariat how to run faster!

Good for you on the 1911. I shot for many years before falling into a groove that worked.

B.B.

 
At September 14, 2009 12:49 PM, Blogger B.B. Pelletier said...

Matt,

I overlooked your question about grip pressure. Bill Wilson is without a doubt a better shot than I am, but I would try it my way and then his, to see which works best.

B.B.

 
At September 14, 2009 12:54 PM, Blogger B.B. Pelletier said...

Everyone,

I do appreciate what hazenadog said on my behalf, but I deleted the message because of name-calling. Back when Edith and I had The Airgun Letter forum we put up with a lot of characters like Wos. We got used to being called names and having our forum attacked. Wos is nothing, by comparison.

However, he has used up all his chances and will be deleted every time he posts. If he says anything, please just ignore his remarks until I can wipe the slate clean.

B.B.

 
At September 14, 2009 1:23 PM, Anonymous Anonymous said...

B.B.

Bill Wilson is good, but I don't know that he is better than LTC Bonsall. Wilson's accomplishments seemed more to do with IPSC type competitions. I didn't see him doing anything like shooting a 2 inch standing group at 25 yards. Wilson does have cool set-ups, though, like multiple plates at staggered distances. Ah, to have a range like that--or the balloons in the Crystal Ackley James Bond video. Very entertaining.

FrankB., send along the ceramic rod to the same address. And thanks in advance. Any new airgunning opportunities at your new place in Huntsville?

Matt61

 
At September 14, 2009 1:25 PM, Anonymous Joe B. said...

Regarding Wos and deleting his posts...

There's a famous story of a Teacher who had a student like Wos. Very negative, he was eventually pushed out by the other students, who were irritated by his continual disruptions of the Master's teachings.

The Teacher, however, went and found the disruptive student and actually paid him to return to the class. The Teacher told his students that the disruptive student was necessary to the Teaching, because he kept the others on their toes.

Frankly, I shall miss Wos. I found him abrasive and startling, yes, but also oddly refreshing at times.

Just a thought.

 
At September 14, 2009 1:28 PM, Anonymous Joe B. said...

BB,

Google "diet gallbladder attack" and it will reward you with tons of good information.

Sorry to hear that you were in that kind of intense pain.

 
At September 14, 2009 1:52 PM, Blogger kevin said...

Joe B.,

I really like your observations and enjoy your contributions.

Must disagree with the analogy though.

Never saw a genuine contribution from this individual. Everything was caustic, inflammatory and very mean spirited. Completely unwarranted and thankfully unwelcome.

Pest control is an unfortunate but necessary part of a blog. Unlike other airgun related blogs that are constantly bombarded by these types, this is the only one that infected this fine blog that I'm aware of. Thanks to B.B. and Mrs Gaylord for running a tight ship.

kevin

 
At September 14, 2009 1:54 PM, Blogger B.B. Pelletier said...

Joe,

Thanks for the Google lead.

B.B.

 
At September 14, 2009 2:00 PM, Anonymous Anonymous said...

joe b., I'll agree with Kevin on this one. After a very ignorant comment on a very legitimate question I posed awhile back, I was actually thinking that if this was the feeling of the posters here I wouldn't be back.
I was quickly informed that WOS spoke for no one here and to disregard the comment.
But what if I was a newbie who was the butt of a WOS comment. Likely I'd not come back and that would be a great loss to the blog than the loss of WOS.
CowBoyStar Dad

 
At September 14, 2009 2:02 PM, Anonymous Anonymous said...

Joe B.,

I am an aficionado of the queen of gallbladder fixers: Dr. Sandra Cabot, and this is the diet Tom said he would follow.

Years ago, my gallbladder stopped working. I used Dr. Sandra's book (Love Your Liver and Live Longer) to come back stronger than ever. Tom is his own person and has never been forced to conform to any diet. He told me yesterday that he's going to follow Dr. Sandra's diet, which is delicious.

Over the years, I've sent copies of Dr. Sandra's book to other people who had gallbladder issues. One airgunner was scheduled for surgery. That was years ago, and he was able to avoid it by following Dr. Sandra's diet. It's a winner!

Edith

 
At September 14, 2009 2:09 PM, Blogger ajvenom said...

B.B. Good luck with the gullstones......and many more years of reporting about airguns!!!!!

 
At September 14, 2009 2:21 PM, Blogger kevin said...

CowBoyStar Dad,

Really glad you stuck around.

kevin

 
At September 14, 2009 2:27 PM, Anonymous Joe B. said...

BB, Edith, airgunners,

Thank you. I'll pass Cabot's liver book title on to my wife, who is currently having liver trouble.

Please excuse my comments regarding Wos. I realize that this is an airgun forum, not a Philosophy or Agape forum, even tho I sometimes forget.

I am, as always, your ardent admirer.

 
At September 14, 2009 2:38 PM, Anonymous wayne said...

Field Target update..

As some might know.. I've been spending lots of time TRYING to improve my field target shooting skills..

Having a course setup on our property has helped for sure.

You might remember I had trouble at the last event with a dark lane and my Nikko 10-50x60 nighteater scope. I had the power set up to 40 and I couldn't see the targets until I turned down the scope power to 20.
I've since upgraded scopes to a used BSA Platinum 10-50x60, which is similar to a newer Nikko Diamond line.. Big difference!!.. incredibly bright and clear even on darker targets on high power... but..
I've set it to 20 power and plan on leaving it there. I've zeroed my 12 ft lb USFT at 22 yards.

I'm still a "holdover" and not a "clicker" guy... so I've taped and marked the side wheel with the fractions of inches of kill zone I see through the scope... ie 1" at 10 yards, 1/2" at 50 yards... but I really don't know or care the distance.. since I just marked the tape as I shot at paper every 2 yards from 10 to 55 yards.. When the scope is in focus.. that's the holdover it takes to hit the target...
What could be easier?.. no wasted time ranging and clicking the turret!
Having the scope power at 20 lets me shoot in the last light of the day with amazing clarity! ... and I have a much larger field of view, so finding the target is faster..
All these time saving things, are important for me, since most times, I've been taking too long to shoot my turn...

So, last Saturday, I shot within time, every time, and scored 39/42 first time though the course, and 41/42 the second time!.. (course Troyer difficulty factor of 33)

Just to show you how Wacky I am... I sent my money in to register for the nationals in TEXAS!!!

Will you be there Edith and Tom?
(maybe film it for the show?)

Very, Very, Wacky Wayne..
I must be totally crazy.. but I love this game!!! ... Thanks, Tom for getting me started!!!

 
At September 14, 2009 2:39 PM, Blogger B.B. Pelletier said...

Joe B.,

Agape, eh? Well, we got your number, brother!

You are in good company.

B.B.

 
At September 14, 2009 2:42 PM, Blogger B.B. Pelletier said...

Wayne,

I'll sure try to get there. Can't let you get this close and not say "Howdy."

B.B.

 
At September 14, 2009 3:02 PM, Blogger Herb said...

RE: Precession and pellets

----
(1) Wonder if pellets precessing is part of why pointed pellets don't shoot as well as domes?

It seems that the rounded surface of a domed would be more aerodynamically neutral to some precession angle than a pointed pellet.

---
(2) There is torque-free and torque-induced precession.

Would a pellet get "torque free" (more like "torque constrained") precession while in the barrel?

Because the pellet has to be formed into the rifling it is highly unlikely that the pellet gets its rotational axis, as imparted by the barrel, aligned absolutely perfectly with its rotational axis due to its moment of inertia. Thus when the pellet pops out of the barrel, the imbalance in the "Torque-free" precession is immediately converted into torque-induced precession and the pellets starts to precess at a somewhat slower rate than it was spinning in the barrel and at an angle to the pellet's path. It doesn't seem like it would take much initially. Maybe even something like a 0.05 of a degree. But as you go down range, things get worse and worse.

[In other words, the axis for the center of inertia of the pellet isn't the center of the boreline of the barrel. The rifling marks get made as the pellet starts to travel down the barrel before it has much spin. After the rifling marks are formed, the center-line for the pellet's spin is fixed. After the pellet starts spinning, the pellet can't tip to an angle because it is mechanically constrained by the wall of barrel. So its precession due to its "torque-free" precession is the same as the spin rate induced by the barrel rifling.]

This would be why shooting pellets faster would be bad. They get more "torque-free" spin in the barrel which causes more of a "torque-induced" precession when the pellet pops out of the barrel.

For example consider a cylinder of lead corkscrewing down a 0.22 barrel, say at a 0.0001 of an inch out of true center, and down a barrel in a vacuum. When it pops out of the barrel, at what angle does it start precess due to its spin as imparted in the barrel? No air involved here. So all of the aerodynamic effects are gone. Assume 1:16 twist, 900fps exit velocity. I'll try to figure this out...

----
All of these notions are frustrating in that there isn't any good way to measure any of these things. You can't due "rough" experiments, you'd need really really good data.

-----

There is an abstract for an oral presentation at the AIAA Infotech@Aerospace Conference, 6 - 9 April 2009, Seattle, Washington

Abstract can be seen at:

http://pdf.aiaa.org/preview/CDReadyMIA09_2070/PV2009_2022.pdf

Title:Aeroballistics Diagnostics Fuze (DFuze) Analysis of a 120
mm Mortar Munition

Basically they replaced the fuse in mortar shell with sensors.

"During the trajectory reconstruction of the four 120 mm Mortar Munition
projectiles, a precession and nutation motion was noted in the magnetometer and yawsonde angular motion
data that was not present in the pretest trajectory simulations. It was determined that the Magnus moment
was causing this motion."

So now we have another culprit that could be causing precession. It wouldn't be necessary for the Magnus moment to make thhe pellet drift significantly, it would just have to cause some momentary imbalance.

A lot of this like trying to balance a pellet longways on a knife edge. Not hard to do as a paper exercise, but try it with a real pellet and a real knife. Some tiny imbalance and the pellet falls off to one side.

 
At September 14, 2009 3:05 PM, Anonymous wayne said...

B.B.

Wow, that would be the greatest!!

I'd so love to meet you and Edith!

So do the diet and get better soon!!

Wacky Wayne,
Ashland Air Rifle Range

 
At September 14, 2009 3:18 PM, Blogger Vince said...

Joe B, nothing means anything without a philosophy, even if it's one that's assumed and not stated. It precedes all things in the human mind... you cannot even have an idea of what is good or desirable without a philosophy defining them.

As for the 'love feast' bit (assuming you mean Agape in a traditional sense), well, have something in Southern NJ and I'll be there!!!

Your comments to Wos were the fruits of what I would argue is a useful philosophy. And a bit more restrained than what I was inclined to write.

 
At September 14, 2009 3:19 PM, Blogger FRED said...

Wayne,

astounding results. You do the entire blog proud. Now don't mess up! :)

Fred

 
At September 14, 2009 3:21 PM, Blogger ajvenom said...

Steve Hoare from Webley responded to my questions:

Q: I was wonder why the word "Senior" is in quotations on the old Webley "Senior" Pistols?

Q: Also, are there any Webley and Scott airguns still made in the U.K.?

A: The Webley manufacturing company ceased trading back in 2005 and so that was when UK made rifles stopped production . the Raider 10 was still made in UK until last year and now has been moved to Turkey with the rest of the range.

A: No real idea what the quotation marks are for around Senior . Unnecessary really .

 
At September 14, 2009 3:21 PM, Anonymous Anonymous said...

I agree with Kevin about the Wos business. It seemed at the very beginning there were a couple legitimate comments, then everything was hateful. I think ignoring anything like that is best, except for CSD's comment that those who are unaware of blog history might generalize from Wos to everyone else. Maybe an exception to blanket silence would be brief comments to anyone new about the blog troll and not to generalize from him.

Wayne, congratulations on your field target successes.

I have a great idea for the Ashland Range: food. I don't have a car, so I have to travel to my range by taxi. I arrive heavily loaded with gear--rifles, pistols, rest bags, ear muffs, goggles, ammo, bows and arrows.... I do believe the old-timers are amused. I don't have room to carry food and drink, and I don't want to leave the gear to go to the bathroom. So, my shooting sessions take place in a state of starvation/dehydration. Haven't figured out the solution.

Anyway, an army travels on its stomach, so if you have provisions for the shooters that could make all the difference. I saw the regulars, once, grilling burgers at the range, but with the lead content in the air, I don't know if that's such a great idea. The menu gets tricky. Nancy Tompkins says not to eat a big meal when shooting, so she just eats fruits and nuts and stays hydrated. I guess no heaping plate of cream chip beef--until afterwards. Anyway, if you meet the need here, somehow, it might make a difference.

By the way, in your exhaustive list of sight corrections, do you notice lateral movement as you move outward as you would if the pellet followed a significant helical pathway?

Matt61

 
At September 14, 2009 3:27 PM, Blogger ajvenom said...

almost forgot....GOOOOOOO WAAAAYYYNNNEE!!!!!

win one for the holdover crowd....


nice scope too.

 
At September 14, 2009 4:47 PM, Anonymous wayne said...

Fred, Matt61, and Ajvenom,

Thanks very much!

I'm really putting in the practice time, since the range is in my backyard! .. so to speak.. and after dark... indoors practice in the pool room..

maybe I need a new handle like "Holdover Harry" or something..

Next Saturday, I'm going back up to Washington St. This time to Tacoma, for their state championship match. My mentor, Rick Knowles, (who is the match director at the Tacoma club, and will be setting up the course!!), just won the Idaho state match last Saturday, so it would only be fair for an Oregonian to go up there and win the Washington state match..... right?

Rick is probably the favorite to win, he was second last year... and he is shooting so well now.. He and last year's winner, and I were neck and neck two Saturdays ago, until the "dark" lane, where I got "skunked" as B.B. put it!...

.. so, with my new brighter scope..I'm lurking in the shadows.. the dark horse.. as they say!

Matt,

My sister has always wanted to own and run a cafe/bar, so she has been cookin up a storm, at the slightest hint of an event.. as well as cooking lunch for our members in the raised bed business... so, grab your guns, bows and arrows, get in the taxi and come on down!!! Tell the taxi driver you'll help with the driving.. he's been wanting a vacation anyway!! ... see ya in a week or so!

Wacky Wayne,
Ashland Air Rifle Range

 
At September 14, 2009 5:52 PM, Anonymous Jane Hannsen said...

Herb:

I don't know why pointed pellets don't shoot well, but my guess is this - the most aerodynamic shape a projectile could have, (ie, a shape that is least effected by air), is a tear-drop shape. This is the shape a water droplet is formed into if it falls freely through air a some velocity.

The "dome" of a teardrop is not too far from a pellet or bullet dome. I think, the farther we get from that shape, the more we succumb to a multitude of forces. A pointed shape can't directly induce more precession, but it may create more, (or less), restorative forces that can alter the gyroscopic response.

I don't follow the "torque-induced" vs "torque-free" comment at all.

If the pellet, either before, or after, entering the barrel, is spinning "out of balance", (ie, it is not rotating around its axial center of gravity), it has a "problem". This problem is going to lead to all sorts of other problems. My suspicion, however, is that this is rare. Pellets are made from large "melts" of lead poured into molds, and in order for this "problem" to exist, the density needs to be inconsistent, or the mold needs to be bad. We already discussed precession that can be induced by defects - in the skirt, the muzzle, etc...

The reason, I believe, that higher velocities cause more problems is because of the deliberate aerodynamics. Drag-stabilized projectiles will exert more force on the "yaw-angle" the faster they go. This force is the "torque" of torque-induced precession.

To me, faster pellets need to be designed with less drag-stabilization built in.

It's even more frustrating at longer distances. Pellets slow down so fast that the POI drops that I calculate at constant velocity are very conservative. In fact, the drop is much more severe, and the "launch angle", and hence the "trim angle" or "yaw angle" is very severe. Higher angles result in higher restorative forces, and more precession.

 
At September 14, 2009 8:10 PM, Blogger Troy said...

BB, those stones are nothing to toy with. My wife had similar attacks for a year before the ER doc figured out what was wrong. The only recourse was bladder removal. The next part is important.
About two weeks after the operation her body was still outta whack. Some looking revealed that a tiny stone had gotten into the duct to her pancreas. This could lead to pancreautitis and ruin the organ. People can't live without it. Another operation got it out but it was touch and go for a bit. Don't take those stones lightly.

 
At September 14, 2009 8:37 PM, Anonymous Mr B. said...

Wayne,

Congradulations on The Win. Shoot well at the next one.

Mr B.

 
At September 14, 2009 8:39 PM, Blogger Herb said...

Jane,

I totally understand the bullet vs pellet shape for high power PCPs. You are flinging lead with a lot of energy.

I'd be curious how fast you could shoot some 30 grain pellets like the Eley Magnum Bullets, Daystate Rangemaster FAC, or the Promethius Piledrive. 30 grains is the equivalent of a 0.22 short. I have no idea if the pellets are any good, the first wonder is simply if you could shoot them at 900 to 1000fps. The spin rate of 1:16 seems typical for a 0.22 firearm, so it seems that something might be possible to effectively turn your PCP into something similar to a 0.22 short firearm.

The Ely bullets look like they would be a friction problem. More contact surface, more friction. The Daystates look like they would have less friction because of the small contact surfaces.

Of course there is the BC. I think a 0.22 short firearm is in the 0.3 range. You wouldn't have your hypersonic round, but anything with a .3 BC would sure carry.

--------

As far as the "torque-induced" vs "torque-free" comment I'll plead guilt to misusing phrases from the Wikipedia article on "Precession." I was trying to think why a pellet would start precessing. It occurred to me that no pellet would be absolutely perfect. It seems unlikely that a pellet's angular moment of inertia would be aligned absolutely perfectly with the centerline of the bore. Close, very close quite probably, but not perfectly. We can measure the speed of light to 9 significant figures. I don't expect that kind of precision for pellet alignment.

Imagine a 0.20 pellet rolling along the inside of a 0.22 barrel as it travels down the barrel towards the muzzle. The pellet is "precessing" around the centerline of the bore, but it can't tip while inside the barrel. In this situation the 0.20 pellet would be spinning around an axis 0.01 inches from its centerline. Once it leaves the barrel, it can tip. The precession causes torque, but the pellet is no longer constrained from tipping.

I'll really go out on a limb and say this is why a choked barrel works. By the time the pellet reaches the choke, it is traveling fast and spinning fast. When it hits the choke, the angular momentum of the spinning pellet forces it into alignment with the slightly smaller bore better than the pellet was in alignment with the larger section of the bore. When the initial rifling is cut into the pellet it is moving very slow, and hence has little angular momentum to help center the pellet into the bore.

With a very small tipping angle, the pellet would precess at a very high rate. This would also cause the BC to go down slightly and cause the pellet to slow faster. As the pellet slows the "tipping angle" would get larger, and the precession rate would drop. You reach a point where the large angle and slow rate of precession cause the pellet to corkscrew.

You mentioned some pellets that grouped well at 600 fps, but grouped much larger when you shot them at 900-1000 fps. I'd bet that if you measured the BC over the first 10 yards that the 600 fps pellets would have a larger value than the 900 fps pellets. I'd attribute the higher BC at 1000 fps to the 1000 fps pellets precessing faster.

 
At September 14, 2009 8:47 PM, Blogger Herb said...

!~@#$

Make that "I'd attribute the --LOWER-- BC at 1000 fps to the 1000 fps pellets precessing faster.

 
At September 14, 2009 9:02 PM, Blogger Al Pellet said...

BB,

You know we appreciate your dedication to the sport and this blog, but for goodness sake! Take care of yourself.

This isn't all for you. We need/want you around for years to come. Get it fixed man!!

My wife suffed and was very sick with this. It almost killed my mom. Don't mess around!

Al Pellet

 
At September 14, 2009 11:01 PM, Anonymous Anonymous said...

Jane/Herb,

How interesting that the teardrop shape is most aerodynamic. I had assumed that longer and thinner is better. Fighter jets come to mind, especially the famous F-104 Starfighter that was good for virtually nothing besides high speed. And I thought that one of the big innovations associated with the 98 Mauser was the invention of a "spitzer" bullet which I've always taken to mean long and thin. The 30-06 bullet, I believe, is a copy of the 8X57 Mauser spitzer bullets and the surplus full metal jacket for my M1 Garand is very pointed and wicked looking.

My own feeling about the source of precession is that almost all of it is due to the effect that Jane mentioned of a force pulling a spinning projectile off-axis and virtually none is due to imperfections in the bore. My evidence is that you can see many football long bombs with only a small, barely perceptible precession. If this can be accomplished with a human hand that is half the length of a ball with 230 lb. linebackers bearing down on the thrower, then a rifled metal barrel many times the length of a pellet will reduce precession to virtual insignificance.

I think precession is a case of the conservation of angular momentum. As to what the force is causing the momentum change, I feel certain it has to do with air resistance and not gravity. I still hold out for the Bernoulli force (not the lift principle which I take as one application of the Bernoulli force, not relevant here since there is no wing). I guess I can see how the enlarged, fan-shaped skirt would create more drag than the smooth tear-drop shaped dome and play the key role in rotating the pellet down in the vertical plane to become tangent to the flight path. Maybe this is what BG_Farmer meant last night.

Matt61

 
At September 14, 2009 11:18 PM, Blogger Boyd said...

B. B.,

Take care of yourself, and get better. Please listen to Edith and do what she tells you.

Wayne,

Congratulations on your shooting,and good luck in Washington.

Boyd,

 
At September 14, 2009 11:47 PM, Anonymous Volvo said...

Wayne,
Congratulations on your shooting success.

Kevin,
Thanks again for the pellets. The Walther is getting closer.

B.B.
Hope you’re feeling better soon.

 
At September 15, 2009 12:27 AM, Blogger Herb said...

Matt,

I wasn't implying that the barrel had imperfections.

If you could spin a stationary pellet about an axis, there is an axis at which the spin would be perfectly in balance. As the pellet travels down the barrel it would need to be spun by the barrel exactly about this same axis. It isn't IF the barrel boreline and the spin axis of the pellet are misaligned, it is a question of how much.

A pellet doesn't have near the contact surface which a bullet has.

My Crosman G1 springer for instance has rifling right to the end of the barrel. I have to admit that I haven't given much thought to pushing the pellets absolutely straight into the bore. I hold the pellet between my index finger and thumb and jab the head into the barrel. I then use my thumb to push behind the skirt and push the pellet flush. When I do that I'm putting rifling marks into the pellet, particularly the head. I have no idea what different angles that I could be pushing the head into the barrel, nor what that means in terms of an error in seating the pellet.

I also didn't mean that all the shooting problems were the barrel. It is just that the motion down the barrel could be one of the factors.

On the flip side, if there are such perfect barrels, and such perfect pellets, why is there such an emphasis on shooting numerous types of pellets to pick the "right" pellet for the each rifle? One rifle may shoot JSB's better than RWS Super Domes. In another rifle it is the opposite. In a third rifle the two types of pellets shoot the same.

An inch group at 40 yards is really quite precise for a barrel given all the other factors that come into play. I doubt many quarterbacks could throw a football 40 yards and hit a quarter.

 
At September 15, 2009 8:32 AM, Blogger B.B. Pelletier said...

Troy,

Thanks for the heads-up. The sonogram showed my stones are not near the ducts (I guess, because the doctor said so) and my gall bladder is pumping bile out rapid-fire. So what I had was an over-production of bile-not a blockage. Had I had a blockage, I might have had to allow the operation.

I'm now starting a stone-elimination diet.

Thanks,

B.B.

 
At September 15, 2009 8:34 AM, Blogger B.B. Pelletier said...

Herb,

The Condor can drive the Eley Magnums to 1,000 f.p.s. I have done it. But they are very hard to load and horribly inaccurate. Same for those Piledriver bullets that came out several years ago (hard to load and inaccurate).

B.B.

 
At September 15, 2009 8:35 AM, Blogger Herb said...

Matt,

RE: applications of the Bernoulli force

The Bernoulli effect is about air pressure differences caused by the relative motion of something with respect to the air molecules.

Yup, the Bernoulli effect is buried into a lot of them. It is sort of like going into an electronics store. There are TVs, radios, cell phone, and computers. But they all have such components as transistors, capacitors, transformers, and such.

"Lift" is used as a label to describe one application of the Bernoulli effect. The Magnus force is another application. "Spin-drift" is another that is thrown about. It is easier to talk about the larger concept than to talk about all the things that make it up.

A perhaps better analogy just occurred to me. It is sort of like saying air resistance is due to gravity. Without gravity there wouldn't be anything to hold the air molecules to the surface of the earth, right? But it is easier to talk about air pressure than gravity. It isn't that gravity is "wrong," it is just that air pressure is an easier concept with which to work when you're modeling airplane lift. Air pressure does have gravity hidden as a more fundamental concept.

-----
RE: precession is a case of the conservation of angular momentum

Yes

--------
RE: what the force is causing the momentum change...

More or less agree, but I'd state the situation differently. We have a number of different sub-models that we can throw into the overall model. What are boundary condition for each? In other words when is it applicable to use a particular sub-model?

Also for some things we have two sub-models. Say low velocity for a pellet and supersonic velocity. Where does the transition occur. What is causing the transition? How do I sub-model low velocity, high velocity and the transition between the two? What causes the transition from high to low? Can velocity go from low to high?

Without a doubt we are talking about a number of sub-models within the total system for pellet flight. The trick is to include enough to cover the observed behavior without throwing in any extra ones which obfuscate what is happening (eg talking about gravity and air pressure).

 
At September 15, 2009 11:47 AM, Blogger Herb said...

RE: Notion about off center pellet at September 14, 2009 3:02 PM

-------
Posed the following problem above in this blog:

For example consider a cylinder of lead corkscrewing down a 0.22 barrel, say at a 0.0001 of an inch out of true center, and down a barrel in a vacuum. When it pops out of the barrel, at what angle does it start precess due to its spin as imparted in the barrel? No air involved here. So all of the aerodynamic effects are gone. Assume 1:16 twist, 900fps exit velocity. I'll try to figure this out...


--------

I've been looking at this and I don't know how to solve this problem or some other simplification of it.

I assume that you could ignore the forward kinetic energy of the pellet.

So this is basically a conservation of angular momentum problem.

Angular momentum inside barrel is equal to angular momentum of cylinder spinning and cylinder precessing out side the barrel.

Think you could save assume that the angular momentum of the cylinder about its long axis is the same in and out of the barrel. So you're basically calculating the "extra" angular momentum because the pellet is off axis to the angular momentum of the pellet precessing. I'm stuck on calculating either of these.

All in all this seems to be some messy calculations. I'm pretty sure that it will involve some differential equations. I'm not sure that the equations could be solve to some simple formulas. My math skills are to rusty for this sort of challenge.

Outside the barrel the cylinder would be precessing about its center of gravity. Half weight up height of cylinder and in the center of the circular cross-section. This is different than having the cylinder precessing as a top. For the cylinder as a "top," the cylinder the cylinder would be precessing on an point of its outside edge of the base.

 

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