Posts Tagged ‘smoothbore’

Original Bugelspanner: Part 2

by Tom Gaylord, a.k.a. B.B. Pelletier

Part 1

Buglespanner spring-piston air rifle
B.B.’s Bugelspanner.

It’s been a while since I wrote about this gun, I know. Airgunner Larry Hannusch told me how to disassemble it, and I started…only to stop when I encountered a barrier. I’ve resolved that barrier, and today I’ll show you the inside of my gun to the extent that I’ve disassembled it.

Larry told me to remove the screws on top and beneath the action that were obvious, then separate the two parts — action and stock. I removed 4 screws, and the action came loose from the stock a little bit. Then, it stopped cold. That was where I stopped working and set the gun aside. Yesterday, I picked it up and began from that point.

A bugelspanner (actually, correctly spelled buegelspanner or bügelspanner since the u has two dots — called an umlaut — over it) translates to a triggerguard-cocker. The triggerguard is pulled down to retract the piston and set the sear for firing.

Bugelspanner triggerguard is up
Triggerguard is up in the shooting position.

Bugelspanner triggerguard is down
Triggerguard is pulled down to cock the springs.

The triggerguard lever is fastened to a pivoting axle bolt located in the back of the stock. The bolt shows in the photos above. Since this lever is connected to a linkage that’s connected to the back of a piston held under tension by powerful mainsprings, it made sense to me that it had to be disconnected from the piston for the stock to separate.

I removed the bolt that screws into a very long bushing inset into the opposite side of the butt. Then that bushing was tapped out the other side of the stock. But the cocking lever wasn’t quite free. At the top of the triggerguard lever, the cocking linkage passes through the lever and is prevented from coming free by a small screw that passes through one end of the linkage. I have arranged the two parts and their screw below for you to examine.

Bugelspanner cocking linkage
The triggerguard and cocking linkage, arranged as they are in the gun — I think! Until I assemble the gun, again, I won’t be sure of the correct orientation of the cocking link.

Bugelspanner cocking linkage screw
That tiny handmade screw goes through the hole in the cocking link and prevents it from slipping through the triggerguard when the gun is cocked. Notice that it has two smooth bearing surfaces — one on either side. As the gun is cocked, the cocking link moves up and down in the cocking slot that’s in back of the triggerguard. It’s a moving fulcrum.

Bugelspanner triggerguard pivot bushing and screw
This is the triggerguard lever pivot bushing and screw on which the lever pivots when during cocking. Note the smooth band around the base of the bushing. We may assume that’s where the pivoting happens.

Bugelspanner triggerguard pivot bushing screw hole
The screw and pivot bushing have been removed from the stock.

Bugelspanner triggerguard cocking linkage slot in stock
The entire underside of the stock is open, allowing room for the cocking linkage to move.

When I removed the cocking link from the back of the piston rod, I found the screw that attached the link to the piston rod was sheared in two, plus the rest of the screw was very mangled from pressure and work. Clearly, this part is too soft and also overworked.

Bugelspanner triggerguard cocking link attachment screw
The screw that holds the cocking link to the rear of the piston rod is mangled and galled from too much strain. The threaded portion remains in the back of the piston rod and needs to be removed. This part may need to become a roller bearing.

The first part to come off the gun was actually the top action plate that also holds the rear sight. It is the anchor plate for 2 long screws and one short one that holds the action together. Once they were out, the plate didn’t come off without a lot of wiggling and some prying.

Bugelspanner top plate
Three screws, and the top plate came off with the rear sight attached.

Bugelspanner stock inletting
This is where the top plate came from.

The gun is now partially disassembled. The double-set trigger mechanism is exposed and can be disassembled and cleaned, but the piston is still under compression inside the compression chamber that hasn’t yet been separated from the barrel. To see the piston and mainsprings, The backplate that the piston rod passes through has to be drifed down out of its dovetail

Bugelspanner trigger assembly
The double set trigger assembly is now exposed for cleaning and possible disassembly. To remove it from the gun, it’s tapped down, freeing its front dovetail.

Bugelspannerbarreled action
The double-set trigger assembly must now be removed downward from the cylinder dovetail, freeing the trigger plate and back plate from the cylinder and relieving tension on the mainsprings.

I found the number 80 on many of the larger, unique frame parts. I believe that’s either a serial number or an assembly number to keep all the parts together because this gun shows a lot of handmade parts and hand-fitting.

When I open the barrel, I see some dark particles that I believe are small chunks of leather that have broken off the piston seal, so it may be deteriorating. And I need to look at the condition of the mainsprings, plus probably lubricate them just a little.

The bottom plate on which the double-set trigger sits is dovetailed into the frame (the rear of the compression/spring tube). It has to be pushed straight down to relieve tension on the mainsprings, and I do this with by tapping with a rubber hammer. The plate comes out of the dovetail easily enough; but the double volute mainsprings are under considerable tension even at rest, and the trigger plate and separate backplate fly off the gun along with the volute springs.

Bugelspanner trigger plate and cylinder back plate
The trigger plate has a dovetail at its front that grabs the rear of the cylinder and holds the powerplant together. The cylinder back plate (left in the photo) is held between the 2 parts. The black part that’s flopping down on the back plate is the sear.

The piston can now be withdrawn, and I can see that the leather seal has, indeed, deteriorated. The part that comes in contact with the air transfer port is damaged from repeated impacts. I think I’ve found the reason the gun fired so roughly.

Bugelspanner piston
Bugelspanner piston at the top is much fatter than the Beeman R1 gas-spring piston unit below, but the stroke is also shorter. The notch in the bugelspanner piston rod is the cocking notch.

Bugelspanner piston seal
The leather piston seal has deteriorated. It looks okay, but it’s crumbling and flaking off. This is why the gun fires so harshly.

Bugelspanner mainsprings
Double volute springs attached to a central guide for the mainsprings of the bugelspanner. They’re in good condition but very dirty and dry.

The double-set trigger has a weak front trigger leaf spring, which accounts for it not setting well and firing too easily. That will also have to be corrected.

The inside of the compression chamber is filthy, but it doesn’t seem to be damaged. A good cleaning is all it needs.

For many of you, looking inside this airgun is probably like looking at the dark side of the moon. So many of the parts appear foreign to your eyes. All that has really changed over the years, though, is how the parts are designed. They work in the conventional way that modern spring-piston parts work, so they must be corrected in the same way that a modern spring-piston powerplant would need to be.

There are numerous major repair jobs that must be undertaken before this airgun will shoot again. There’s certainly lots of cleaning, which is followed by careful lubrication of many of the parts.

Some new parts have to be fabricated, as well. That will not be an easy task, but it’s worth the effort. I know you were hoping to see a test real soon, but that’s not going to happen. I have to feel my way around this gun carefully; because if every job isn’t done right, the gun won’t work when it goes back together. I’ll go about the work methodically and take some pictures as I go, but I probably won’t report on the gun again until all the work is completed.

Original Bugelspanner: Part 1

by Tom Gaylord, a.k.a. B.B. Pelletier

Buglespanner spring-piston air rifle

B.B.’s bügelspanner.

Today, I have a story for you. A couple weeks ago, one of our blog readers — a man named Eric — emailed me a link to a local craigslist.com posting. Eric met me at a gun show last year, and I sold him a Winchester model 427 (Diana 27) air rifle. He already knew about fine vintage airguns, and the 27 had been on his wish list for a while, but I don’t think he was a blog reader. Well, we fixed that right away! Since then, he’s been reading the blog and becoming more familiar with his new rifle and airguns in general

The listing he sent me showed a Tyrolean air rifle with the traditional high-cupped cheekpiece and hooked buttplate. What was even more fascinating were the double-set triggers and the large aperture sight located at the rear of the receiver, as well as the sporting sight mounted on the barrel.

The gun was a bügelspanner, or loosely translated, a triggerguard (lever) cocker. I’ve owned 2 bügelspanners in the past, but neither was as nice as this one. And the funny thing is that this was posted on craigslist! That’s funny because guns are sold on gun websites — not on a general website like craigslist.

But this posting had lasted for a minimum of 2 weeks before I saw it. So, I contacted the seller and, glory be, he still had it! We met last Sunday, did the transaction and this was one of those rare times when the gun was exactly as represented.

The gun is a smoothbore .25-caliber gun. The seller, named Joe, told me he had owned it for the past 34 years and had gotten it at the age of 8 as a gift from his father. The gun is much older — probably dating back to around the 1920s or ’30s.

It’s a spring-piston gun that has 2 opposed volute springs that compress against each other. They push a leather-covered piston in the same way that a coiled steel mainspring does in a conventional spring-piston gun, so this is just an odd form of spring-piston airgun.

Gallery volute springs and piston
Two volute springs push against each other when compressed.

Volute spring
The volute spring is a flat spring that’s been coiled and stretched into this shape.

Zimmerstutzen style
I was attracted to this airgun because of a long, abiding interest in zummerstutzens — indoor gallery or parlor guns used for target shooting. I’ve been fascinated with them since I was a teenager and first read about them in Guns & Ammo back in the early 1960s.

The zimmerstutzen rifle is usually found in the Tyrolean style, but not always. It’s nominally 4mm, but there are more than 20 specific calibers for which the guns were bored. They fire either fixed ammunition (a cartridge) or separate ammo with a percussion cap and round lead ball loaded separately. Rather than get into the full description here, I invite you to read my full article about them. I normally don’t like giving homework assignments; but if you read that article and look at all the pictures, you’ll have a much better understanding of the gun we’re examining today.

The subject gun
I was inclined to believe the subject gun is a dart gun, but what little historical documentation there is mentions using pellets as well. I thought it was a dart gun because it’s set up for extreme accuracy, and I didn’t think that pellets could be that accurate in a smoothbore barrel. But we did do a test of the Diana 25 smoothbore at 10 meters and established that it is, in fact, very accurate at that distance. So, I really don’t know if I’m supposed to shoot darts or pellets in this gun. For the present, I only have pellets because .25-caliber darts are not that common. But I could certainly make some.

This type of gun either fits or doesn’t fit — there’s no in-between. I’m lucky that it fits me pretty well. But that sporting rear sight does get in the way of seeing the front sight. I would have to remove it to use the rear sight.

Why a sporting rear sight? Shooters in the US are not familiar with how European airgunners view target shooting. They use their guns for both precision target shooting and also for sporting use. I guess the best comparison would be to the Hunter Class of field target. Therefore, European target guns often have both a precision rear peep site and a second sporting rear sight located somewhere on the barrel. The subject gun has both.

The front sight is a fine post and bead, which is typical of all zimmerstutzens and, indeed, of many target guns from the 19th century. This sight is very fragile, so it’s protected by steel “ears” on both sides.

Bugelspanner sporting rear sight
The sporting rear sight is adjusted in both directions by a clock key.

Bugelspanner rear peep sight
Rear peep sight is also adjust by a clock key and can be removed to use the sporting sight, only.

Bugelspanner post-and-bead front sight
Front post-and-bead sight is delicate, so two steel ears protect it.

The gun has an octagonal barrel, which dates its manufacture to before World War II. It’s impossible to get a more precise date than that because these guns were made from the beginning of the 20th century until the early 1950s. The octagonal barrel also suggests a time before 1940. Most likely this gun was made in the 1920s or 30s, but I have no way of proving that.

The name Original is engraved on the barrel. Several sources say that this is a name used by Oskar Will in Zella Mehlis, Germany; but one source says that name, by itself, was used only by his competitors, and all of his guns also have the word Will on them, as in Original Will.

Original
The name Original may mean this gun was made by Oskar Will of Zella Mehlis.

The gun is cocked by pressing down on the triggerguard, which is actually a long lever pivoted near the bottom rear of the butt. You can see the pivot pin sticking through the rear of the buttstock. A linkage pulls the piston back, compressing the two springs. To load the gun, you press a catch forward on the right side of the forearm, and the rear of the barrel can then be tipped up. You could call this a breakbarrel, but the barrel doesn’t have anything to do with cocking the springs. In that respect, the gun is like the breakbarrel Whiscombe rifles.

The cocking effort is pretty demanding. It’s on the order of 40 lbs., at least. I can’t see how a boy of 8 was able to cock this gun, but maybe his father cocked it for him until he grew into it.

Bugelspanner triggerguard is upTriggerguard is shown up…in the firing position.

Bugelspanner triggerguard is downTriggerguard is pulled down to cock the springs.

Bugelspanner barrel is broken open ready to loadPush the catch forward, and the barrel can be tipped up for loading.

The double-set triggers on this gun are interesting. They work in the normal way — the rear trigger is pulled to set the front trigger and the front trigger fires the gun. However, there’s one difference. Many guns with double-set triggers will also fire when the front trigger is pulled without being set. This gun will not. If the trigger is not set, the gun cannot be fired.

Bugelspanner double-set triggersDouble-set triggers function normally, except the gun won’t fire unless the trigger is set. Many double-set triggers will fire when the front trigger hasn’t been set, but not this one.

Joe told me he shot the gun, so I figured it would be okay for me to do, too. First I dumped about 20 drops of 3-In-One oil down the air transfer port and gave it an hour to soak into the leather piston seal. The, I loaded an obsolete 20-grain Diana Magnum pellet and shot it into the trap from just a few feet away. The firing cycle was very harsh, so I won’t be doing that, again, until I can examine the condition of the powerplant. I could hear how slow the pellet moved, which leads me to suspect I’m right about this being a dart gun.

The gun is stocked with a light-colored walnut that’s checkered on the straight pistol grip. Also typical of the Tyrolean stock is the thumbrest that protrudes from the right side of the grip. That makes this a definite right-hand rifle!

Bugelspanner Tyrolean stockThis top view shows how thick the buttstock blank had to be to begin with!

The gun’s metal is finished with a combination of heavy nickel plate and hot-tank bluing. I would put the finish at 80-85 percent, which is to say…a lot! There are pepper tracks of rust scattered around the blued barrel, but an application of Ballistol and steel wool has begun to remove them. I’ll keep this up for as long as it takes to get down to smooth metal.

The future
This report will not follow the traditional pattern of velocity testing followed by accuracy testing. For starters, I think the gun is too fragile to shoot that much, plus it does fire harshly. I need to find out what’s going on inside before I do much of anything.

I made this Part 1 so I could come back to it with a second report, though I have no plans for that right now. But as I learn more about it, there will be enough information to make an interesting Part 2.

Advanced airgun diagnostics: Part 1

by Tom Gaylord, a.k.a. B.B. Pelletier

I don’t know about the rest of you, but this blog is teaching me things. I’m learning a lot more things by doing all these little tests and experiments than I ever learned by reading about airguns. Of course, that’s partly because there aren’t that many good books around, but it’s more because of the excellent discussions we have here. And more often than not, something really special comes from all this study.

Yesterday, I was finishing an article for my monthly column in Shotgun News when I happened to spot something interesting. I was writing about the Chinese KL-3B Fast Deer sidelever spring-piston air rifle and I showed two targets — one shot with RWS Hobby pellets at 10 meters and another shot with the same pellet at 25 yards. The 10-shot group at 10 meters measured 0.38 inches between centers, and the 10-shot group of the same pellet that was shot at 25 yards measured 1.918 inches. That was certainly a huge increase for just moving the target 14 yards farther! But it was more than that. I had seen something similar recently — something that really stuck in my mind.

Fast Deer sidelever air rifle right
Fast Deer sidelever rifle has a quality look, but the accuracy falls off fast after 10 meters.

Fast Deer sidelever air rifle RWS Hobby group
At 10 meters, the Fast Deer put 10 Hobbys into 0.38 inches.

Fast Deer sidelever air rifle Hobby group
But at 25 yards, another 10 Hobbys went into 1.918 inches.

Then I wrote something in the column that jogged my memory. I said the Fast Deer was acting like it was a smoothbore because it shot great at 10 meters but lousy at 25 yards. That was just how the Diana model 25 smoothbore had shot when I tested it last year! And that’s when it hit me. As I remembered it, it was performing EXACTLY like the Diana model 25 smoothbore!

Diana 25 smoothbore
The 1940 Diana model 25 smoothbore performed exactly like the Fast Deer air rifle.

So I looked it up, and I was right. With JSB Exact RS pellets the Diana 25 put 10 into 0.337 inches at 10 meters, and at 25 yards it put the same JSB Exact RS pellets into 2.421 inches after I played with the seating to find the best place.

Diana 25 smoothbore JSB Exact RS deep-seated group
At 10 meters, the Diana 25 smoothbore put 10 JSB Exact RS pellets into 0.337 inches.

Diana 25 smoothbore JSB Exact RS deep-seated group1 25 yards
But at 25 yards, the best the Diana 25 could do with 10 JSB Exact RS pellets was 2.421 inches.

Ah-ha!
Learning has occurred! I now know that I’m getting the same results from a gun with a rifled bore as I got from one that is a smoothbore. Or, to put it another way, the rifled gun shoots like the pellets aren’t being stabilized by the rifling. It shoots like a smoothbore.

Is the Fast Deer even rifled?
Then I wondered if the Fast Deer is really rifled. So, I ran 2 different pellets down the bore from muzzle to breech — have to go that way because the barrel is fixed. Both pellets (RWS Hobby and an old Tech Force Chinese pellet) showed good engraving around the bases of their skirts, but only one showed any contact with the pellet head. Unfortunately, the RWS Hobby that I’d used when testing the rifle did not have any marks on its head. Instead, it was the domed Tech Force pellet made years ago that had engraving. However, I never shot the Chinese pellet when testing the gun for accuracy. Pyramyd Air used to carry them, but they no longer do. The point is, they may solve the longer-range accuracy problem. If they don’t, I will look around for another fat .177 pellet that will.

So what we have is a Part 6 test coming up for the Fast Deer rifle. I said I would scope it and shoot it at 25 yards for Part 6, but if it doesn’t shoot accurately with open sights at 25 yards, that seems like a big waste of time.

Airgun darts

by B.B. Pelletier

Update on Tom/B.B.: When I visited him Monday afternoon, we discovered that he’d lost 50 lbs. of water in less than a week. All vital signs are stable and things look quite good!

Today’s blog was written by B.B., but we have an announcement first.

Pyramyd Air is having its 3rd Annual Airgun Garage Sale on June 5. As in previous years, there will be a mountain of guns and accessories with slashed prices and dented pellet tins at huge discounts. Come early, bring cash or credit cards, and shop til you drop!

Now, on to today’s blog.


An airgun dart is very accurate due to the high drag of its animal hair or fiber skirt. It’s forward-weighted and has fletching, just like the hand-thrown dart.

Here’s another subject I’ve hit before: Darts in airguns. Back in the 1600s, darts were the most accurate ammunition available for airguns. They were considered for target use only, were very low-powered and were shot from smoothbore guns of approximately .40 caliber. When airgunners see these old guns, they imagine things that just aren’t true, such as shooting them with lead balls, bullets or pellets. The truth is that darts were at one time a very popular airgun ammo.

The progression: from then to now
The early darts were very carefully made with metal bodies and animal hair fletching. Accuracy was controlled by removing hairs from the tail of the dart…one at a time. One hair was always a dark one, and that one never got removed. It was the way you oriented the dart in the barrel of the gun each time you loaded (e.g., always put the dark hair at the 12 o’clock position in the breech).

In the 19th century, they started producing darts with machines. This made them cheaper to buy but considerably less precise. They were still the ammunition of favor until the late 1870s.


The felted slug acted like a modern diabolo pellet.

Henry Marcus Quackenbush
When H.M. Quackenbush brought out his popular line of airguns, he also made darts for them, and that was considered their best ammunition. Later, he brought out several different types of ammo for the same guns. Cat slugs were solid lead cylinders with felt glued to the tail. The felt acted like a modern diabolo waist and flared skirt, creating high drag that kept the slug on track. Later still, some H.M.Q. guns were made to fire modern diabolo pellets and lead balls. Once, again, they were never very fast because of their roots in a dart gun design.

After WWI, the popularity of darts faded quickly. Webley kept them alive for their smoothbore pistols, most notably the Junior model, on which I reported recently. By the 1950s, the concept of the airgun dart was not very well understood in the USA. Benjamin made and sold them for their smoothbore guns that were also BB guns. But, most owners paid no attention and shot the metal body darts in their guns with rifled brass barrels!

You can still buy darts, but not many people do. A good dart gun is very low-powered and a very smooth shooter. Anything else defeats the purpose. They’re not, as some airgunners believe, super-penetration hunting ammunition.

Before I sign off today, I have another announcement.

Oehler 35P now available again
Most of us are more than happy with our Shooting Chronys, but a few of you have asked me for years about getting an Oehler 35P printing chronograph. I’m not here to sell an Oehler to you, but there’s no substitute if that’s what you really want.

The new package includes 3 skyscreens, a skyscreen bar, tripod, chronograph with built-in printer, and diffusers…all packaged in a hard rifle case. The Oehler is the only chronograph I know of that has a second proof channel that constantly compares to the output of the main chronograph channel. Both channels print out on the built-in printer. The price for this package is $575 with shipping (which is an introductory offer). At that price, this product isn’t for everyone. For 95% of my testing for Pyramyd Air, I use a Shooting Chrony.

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