by B.B. Pelletier
Photos and test results by Earl “Mac” McDonald
Announcement: Anthony Stewart is this week’s winner of Pyramyd Air’s Big Shot of the Week on their facebook page. He’ll receive a $50 Pyramyd AIR gift card.
Anthony Stewart’s photo of his cousin shooting his Red Ryder is this week’s winner of the Big Shot of the Week. I’d say this boy really wants to shoot since it appears he’ll do whatever it takes to make a too-big gun work for him.
The Diana model 60, which is a Hy-Score model 810 in this case, is a breakbarrel target rifle from the 1960s and ’70s.
Today, we’re looking at the accuracy of the Diana model 60 recoilless breakbarrel target rifle. In Part 2, I also reported on my HW 55 CM, but now I’m back with the model 60 exclusively. All along, I’ve been baiting you with the incredible accuracy of this rifle. Today is the day we’ll see what that means.
We learned that Mac’s model 60 suffers from a loss of velocity over the factory specs. Blog reader Mike Driskill was kind enough to give us the velocities of his two model 60s. The first rifle is one that he suspects still has the original factory springs that came with the gun. It got a new piston seal back in 1999 from RWS USA. It shoots RWS Hobby pellets at an average velocity of 567 f.p.s.
The second model 60 is one rebuilt by Randy Bimrose, who commented that it was the hottest model 60 he had ever seen. That rifle averages 666 f.p.s with the same RWS Hobby pellets.
Mac didn’t shoot his rifle with Hobbys, nor did he test with any of the same pellets Mike did, but with H&N Finale Match Rifle pellets it averages 457 f.p.s. I will make an educated guess that his rifle might shoots Hobbys at 495-510 f.p.s., based on that performance. It’s slower than Mike’s slowest rifle and perhaps it has the original springs with an updated piston seal.
Velocity is not something we look for in a fine target rifle, but nobody wants their gun to be performing substandard, either. Mac still hasn’t decided what he will do about the gun, but I believe he will send it off to be rebuilt. Pyramyd AIR is now fixing all Giss system rifles and pistols, so Mac knows where to send his gun to get it refreshed.
Back to accuracy — the sights
But today isn’t about velocity. It’s about how accurate this rifle is. I’ve made some strong claims for it in the past, so it’s time for me to show the evidence.
When we talk about accuracy, naturally the sights come into play. The Diana 60-series rifle sights are interesting and very well-built. Let’s begin with a look at the sight base that many of us have mistakenly called a scope base for years.
The Diana rear sight base has grooves running perpendicular to the axis of the action along the top of the entire sight base. To most of us, these look like an interesting but useless detail; but if you own a Diana peep sight, their real purpose springs into sharp relief.
The rear sight base on the Diana model 60 rifle has ridges that run perpendicular to the action of the rifle. They’re locking grooves.
The underside of the target sight has corresponding grooves that mesh with those on the sight base, locking the rear sight in position.
When you see the underside of the target rear sight, you see the corresponding grooves that bear down and intermesh with the grooves on top of the sight base, locking the sight firmly in position. One wonders why Diana never marketed scope rings with the same feature.
Yes, the model 60 is recoilless and probably doesn’t need its sight to be locked down, but the same sight base is found on their recoiling sport models made during the same timeframe. It’s easier to make the parts the same for all guns, so even the recoilless rifles get this locking feature.
Mac says he’s very intrigued by the level of sophistication he finds in the Diana target aperture sight. He took some detailed photos so I could share it with you.
This view shows the back of the rear sight, which contains both scales for windage and elevation adjustment. Both adjustment wheels have click detents that alert the shooter to exactly how far the sight has moved during adjustment.
The front sight accepts different inserts, like most target sights of that era. Mac discovered that it also accepts the clear inserts that have become very popular in recent years.
And now the targets
The proof is in the pudding, as they say, so let’s see how this target rifle shoots. First up was the venerable RWS Meisterkugeln, a time-honored wadcutter that has been around for most of the modern airgunning age. I used them back in the mid-1970s, and they’re still going strong today. Mac found them to be reasonably accurate in his rifle.
Five RWS Meisterkugeln made this group at 10 meters that measures about 0.19 inches.
Next Mac shot the H&N Finale Match Rifle pellet. It grouped just about the same as the Meisterkugeln , though the group was centered on the target better.
This group of five H&N Finale Match Rifle target pellets is more centered than the Meisterkugeln pellet group but measures about the same size.
So far, the rifle has shown accuracy that is average for a good 10-meter rifle. But next up was the JSB Exact Diabolos, a domed pellet that Mac uses for mini-sniping. The group these pellets shot was so small it was almost impossible to measure; but by being generous with the calipers, Mac estimates that it measures 0.10 inches between the centers of the two shots that are farthest apart. That’s the sort of accuracy seen in today’s top target rifles, so the model 60 gives away nothing to modern guns except ergonomics.
JSB Exact domed pellets gave the best group of all in Mac’s rifle. These five appear to have grouped in 0.10 inches at 10 meters.
The bottom line
This report has been about a breakbarrel target air rifle that’s just as accurate as any fixed-barrel target rifle we see today. It proves the point that the breakbarrel system can be just as accurate as any other spring-piston system.
The report also reminds us that there are a lot of vintage airguns around that can be every bit as nice as they were 40-50 years ago when they were the latest technology. Fortunately, we live at a time when they are also repairable, so these vintage treasures can continue to serve us well in the years to come.
I’d like to thank Mac for taking the time to test his fine old target rifle and share the results with us in this blog.
PA Blog Index for July 2011
1. Today’s special: Mac’s favorite guns!
4. Testing the Air Arms Pro-Sport: Part 2
5. What would B.B. do? Part 1
6. Does glass-bedding your air rifle improve accuracy? Part 2 (Fred PRoNJ)
7. GSG 92 CO2 BB pistol: Part 1
8. HW 55 Custom Match: Part 1
11. New BKL mount adjusts for barrel droop: Part 1
12. What would B.B. do? Part 2
13. Does glass-bedding your air rifle improve accuracy? Part 3 (Fred PRoNJ)
14. GSG 92 CO2 BB pistol: Part 2
15. Diana model 60 recoilless target rifle: Part 1
18. What would B.B. do? Part 3
19. Myths of the multi-pump
20. Testing the Air Arms Pro-Sport: Part 3
21. Sam Yang Dragon Claw .50 caliber big bore air rifle: Part 1
22. Diana model 60 recoilless target rifle and HW 55CM: Part 2
25. GSG 92 CO2 BB pistol: Part 3
26. Testing non-lead pellets: Part 1
27. BSA Comet breakbarrel air rifle: Part 1
28. Sam Yang Dragon Claw .50 caliber big bore air rifle: Part 2
29. Diana model 60 recoilless target rifle: Part 3
BB,
Now that’s what I call some fine shooting and what a target should look like from a really fine air rifle.
Don’t have any rifles with the giss system but I have a RWS Diana 6 with adjustable wood target grips. It is a very accurate pistol. And the recoil is non-existent.
Sure wish I did have a good rifle with the giss system to go along with the pistol.
Maybe some day!
Mac,
Nice shooting and great photos, thanks for the report.
I have to make a confession…. The only sping piston rifle in the family armory is an old Red Rider my wife got as a child. This report prompted me to draft an amendment to the house hold parliament bill that will make a special exception to the debt ceiling to allow the purchase of one of these beauties if one comes by.
Caveman,
Perhaps you should enquire of the establishment of Mr. Scott Pilkington. It was reported in this tome back in April that he was in possession of a sum of former club target rifles like this one. Scott is the USA armorer for the US Olympic Airgun Team, and he operated a small establishment known as Pilkguns.com.
B.B.
Scott has just a few left, but a couple are new-in-box. I scored an FWB-300s with a fair condition stock and a very nice action. Give him a call.
Holy pellet gun, Batman. That’s some fine shooting!
Fred PRoNJ
Those groups are all off hand of course. 🙂 BB’s having a good day!
Mike
Mike,
They WERE all offhand! How did you know? 😉
I even fired them by remote control 1,200 miles away!
Things like this are so easy for me.
B.B.
Would that be while shooting left handed, blindfolded, standing on one leg during a 60 mph gusting wind and a 6.5 earthquake while being attacked by bluejays, horseflies, skeeters, and rabid dogs ?
twotalon
twotalon,
Not hardly! I hate horseflies.
B.B.
Strange enough, this year there didn’t seem to be any skeeter or deer fly problems. It kept raining until long after it should have stopped this spring. Maybe they all drowned.
The friggin’ horse flies are a different story. Right now they swarm anything they see move.
twotalon
And here I was thinking the real secret was that the mosquitoes were pulling the pellet out the barrel, handing it over to the horseflies which carried it to the target where the birds would take it and punch it through the bull.
Like my friend Brian says, Giss bliss! Over the past few years, I’ve experimented with most varieties of vintage recoil-less match rifles. The FWB 300S uses a sliding action. The Anschutz 250 uses an oil-filled internal shock absorber. The Walther LGR is a single stroke pneumatic. And my Diana 66 is of course a Giss rifle. Of the four, the 66 is the only one I kept. FWBs are quite plentiful on the used market, and are a joy to shoot. But I found the movement of the rear sight a little disconcerting. Not bad, just not ideal for my tastes. The Anschutz 250 shot beautifully as well, but it was considerably longer and heavier than the other offerings. The Walther LGR, being a single stroke pneumatic, did have some sense of recoil, most likely due to the moving mass of the hammer striking the valve. It was rather ponderous as well. Only the 66 is truly without felt recoil. And the unconventional angular stock actually fits me better than any of the others. I recently experimented by removing the barrel sleeve, which makes the gun much less muzzle heavy, and dramatically improves the handling. Good to know that PA now services these fine pieces of watchmakers’ art.
BB, please help !
I haven’t even read todays blog yet but, seeing the winning picture at the top, I have a perfect chance to ask my question. My ten year old grandson started out shooting his new Daisy # 25 BB gun EXACTLY like the boy in the picture. I wanted him too learn correctly, so I cut 2″ off the stock. He now keeps the butt against his shoulder as he should. Before I had a chance to feel proud of myself, I noticed another problem [I think??] that I’m ashamed I didn’t notice before. Although he shoots RIGHT HANDED, he aims through the open sights with his LEFT EYE. Being a little boy, he is able to get his left eye low enough too align with the sights, and is actually a pretty good shot ( Proud Grampa ), but I know as he grows it will get more difficult. I know I can’t do it. He plays all sports right handed. He writes right handed. Dr. says his eyesight is fine. I’m thinking my only options would be to FORCE him ( he is being stubborn about this ) to learn to shoot left handed, or force him to sight with his
right eye, OR, to just leave him alone and let him have fun. Last time I put black tape on the left lens of his safety glasses which worked pretty well but he stopped shooting much sooner than he usually does. I don’t want to turn him off to the shooting sports, and would appreciate suggestions from anyone who has them. Thanks, JR.
JR49,
One of my 13 year old twin boys has the same core issue – right handed, but left eye dominant. Unfortunately there is not a lot of great options. The solution my son likes best for long guns (pistols are no problem) is a pair of safety glasses with the left lens “fogged” up. We did this by using 600 grit sandpaper lightly on the lens. This stops him from having to fight the image that his dominant left eye sees, but is far more comfortable (in terms of eye strain) for a longer period of time than a blacked out lens with the great disparity in the amount of light hitting his two open eyes. The good news is that the more time he spends shooting with the glasses this way, the stronger the right eye will be and it may reduce the impact of the issue – but it may never go away to the point where he can shoot as comfortably as someone whose eye dominance matches their handedness.
You can “Train Your Brain” and switch eye dominance if you want to. The short explanation is to patch the dominant eye while shooting. After a time, you won’t need the patch anymore as the dominance will have changed. The scratched lens will do it with time too. It just takes a while but it will work.
Mike
And then there is me…
My normal pair of glasses is configured with the left eye focusing about 20 inches (computer terminal distance) and right eye set for “infinity”. My reading glasses are configured for about 12 inches (I typically read on the couch with plate wedged between wrist and collarbone and the book held above it). My sunglasses are set for infinity in both eyes.
I’m right-eye dominant except… when something approaches that eye, at which point I seem to shift to left eye… makes normal shotgun work difficult as raising the gun to my shoulder means the receiver is “approaching” my right eye — and suddenly my left eye is looking across to the bead.
I would say just let him do whatever seems right for him.
My brother is cross dominant and right handed, but he shoots left handed. Some just get used to using the wrong eye. The brain can switch over pretty fast if it gets enough practice.
You can get used to switching hands or eyes either one after a while. One or the other will seem more convienient.
twotalon
JR49,
Shades of 1947, when teachers forced all the little kids to write cursive right-handed!
Your grandson is probably left-eye dominant. A century ago, when gunmakers were more tolerant of situations like this than primary education specialists of the 1940s, they made shotgun shocks with bent stock, so a person could hold it on their right shoulder by sight with their left eye.
Look here:
http://www.gunsamerica.com/903825434/Guns/Shotguns/Classic-Doubles-Shotguns/GERMAN_CROSSOVER_STOCK_O_U_SHOTGUN.htm
Leave them alone and they will come home, wagging their tails behind them.
B.B.
A young lady (about 20) I was teaching to shoot kept doing that with a Gamo Delta. I forced the issue, forcing her to use her right eye – and I don’t think it took more than a half-dozen shots before she got used to it. Now she’s fine with the right eye.
B.B.,
Is it possible that the last group would appear to be smaller because the pellets are domed, as opposed to wad-cutters, which cut nice, wide, holes? I’m not questioning whether or not the groups are smaller, I am questioning how much smaller they might actually be.
Victor
Victor,
Yes, that is possible, but Mac allowed for it. Still, it was very challenging to measure that one group.
B.B.
B.B.,
Yes, I can imagine. Those are VERY nice groups. That rifle has proven itself to be very fine.
Victor
I lost my oncologist today. No more paychecks for him ! He told me to get lost and not come back.
twotalon
TT,
Woohoo!
Edith
He decided that visiting him was a waste of time. My opinion too.
The ENT (Dr. nose hose) is my main man. Followups with him are more frequent and in depth.
It’s pretty much the elimination of unneeded time and money spent.
twotalon
twotalon,
Excellent!
It’s wonderful to fire a good doctor.
B.B.
Twotalon,
Congradulations! I’m sure that must be a load off your mind. I’m happy for you!
Victor
TT: yeah!!!
Hi, everybody.
-Jan
Tghis was missent directly to me:
Hi Tom
First I want to say thank you ! I really enjoy your Podcasts !
My question for you is, I just purchased a Crosman 357W Revolver, after I installed a Crosman Red Dot Sight onto the ventilated rib I noticed the rib was not tight to the barrel(I could wiggle the sight sideways, left to right). I tried to tap the rib down with a plastic head hammer but it dented the rib. Any suggestions ?
Thanks
Jay
Jay,
Once plastic breaks there is no good way to repair it. Perhaps epoxy?
You have voided the warranty by denting the rib, so sending it back isn’t going to work in this case. I think epoxy is your best solution.
B.B.
Wild boar is open season with no bag limit all year here. Sounds great, right? Problem is that there ain’t none around here. I bought my Gamo for nothing !!
twotalon
Twotalon,
Apparently there are some residents in New York who would like to have your number. lol 🙂
Victor
TT,
Allow me to add my very heart felt congratulations to you. On the other hand, there are no boars or mother-in-laws for you here in NJ either.
Fred PRoNJ
Well…I don’t know if my Gamo would work on mother-in-laws anyway. Gamo don’t have a video.
twotalon
twotalon,
I hope what you are saying is that you have recovered enough that you do not need this doctor anymore. There are lot of readers on this blog, including me, who are thrilled to hear that. I don’t know what an ENT Dr. does but I hope you get rid of him, too, and soon.
ENT…ear,nose,throat. Pretty much anything above the shoulders. Still will have periodics for at least a year to see if he finds anything new.
twotalon
TT,
Congratulations on shaking this bug!
Now you can focus on the more enjoyable things in life.
Les
Wow, I don’t think I have ever seen groups that tight. Mac, I do believe you made that gun shine!
TT,
I am very happy for you. Whatever you were doing, keep it up!
Lloyd
American Airgunner this morning 9 eastern…..pidgeon hunting, and the Dragon Claw .50.
twotalon
Some springer observations….
My 97K and R9 were slowing down. Both were still buzzing. Vortek kitted both and got back to original out of the box velocity….860 (R9) and 830 (97) with 8.4 gr. No buzz now.
Ran the R7 over the chrono while I was fooling around and found that it had started losing ground. Gave it some chamber oil and it came right back to what it had been. Decided to try some with the R9 and 97. The 97 came up to just under 900 and the R9 just over. Waited a few days and checked them again. No change with the 97, but the R9 came up a bit more (920’s).
Checked the 48 and it had also lost a little. Oiled it and it came right back up to what it had been.
No smoke or mist cloud after a few shots with any of them. Sillycone does not tend to burn, but may wash up some of the other lubes when present.
So what am I looking at here? They don’t always speed up with more shooting. Factory “no lube required” does not seem right. Moly does not seem to work best when it gets on the seal. Factory lube may not be the best. Velocity loss can happen in a short time without shooting a great number of pellets. (none of these rifles have been shot to any great extent…I have too many for that).
Looks like they might like a drop of oil or two after each tin of pellets. That seems about the point that they start to fall down.
twotalon
TwoTalon,
A drop of silicone chamber oil every tin or two seems to work well, some more and some less, in my very limited experience. Strange that is the manufacturers recommendation in many cases :). I agree that the moly on the seal doesn’t do anything for lubrication but make the user feel better: Unless both contact surfaces are metal, it is probably wasted, except there may be enough petroleum grease in it to both lube and burn a little, which may give people the numbers they want or even it out consistency-wise.
You could weld up the Titan piston’s sear surface to harden it if you could figure out the right rod.
And another update…
Titan problems with the sear hanging up and causing hangfires if cocked too long…….
Thalked to Gene at Air Venturi and discovered that a soft piston can also cause the sear to hang up. Crosman does not supply parts or any information on this rifle to them.
Checked it out and found that the sear was eating into the piston.
Possible solution….construct a forge and try to harden it, but just too much work after everything else with this rifle.
Checked velocity and found that it had lost a good 100 fps. Seemed to be cocking a lot easier than it had been. Oiled it with little help. Looks like the ram is giving it up.
Calling this one dead meat.
twotalon
B.B.
Got something to work for a change.
R9 with new Vortek running smooth.Had to replace scope for right turret problems. New scope works.
Four different kinds of pellets this morning while it was cool and before the horseflies got warmed up. Scope not re-indexed yet for range. 25 yds.
AA 4.52 shot a little loose. Superdomes shot a horizontal string with a tight verticall spread. FTT 4.50 and Exact heavy shot good groups of 3/8″ or less (pretty close to my wobble factor) and to the same POI. No real difference in group size with the best I could hold.
Zero set to + 1/4″ at 25. Ftt running a little over 900, and Exact heavies at a little over 800.
I am happy. (for a change)
twotalon
B.B.
I wish I owned one of D-60…
Well there are some D-60 and D-75 in posession over here, they were bought for olympic youth training and several were imported for a brief time in early 90’s. Since then there are a few men who want to part with this rifle. Almost no such rifles on secondary market.
On my own recoilless – I had to rework pistons a bit, but now I’ve got them both the same – of equal weight and now I’ve got unified pull and catch levers. JW’s have them united in one ratchet unit but I felt it was a bit too complicated for the first try, so in my case rear is for cocking, front is for catching. This adds to security – one can not shoot the rifle with cocking lever opened – first sear it blocked and if it goes off – there’s still a catch lever to stop pistons. However you can safely de-cock rifle – you just got to know where to press, and close the cocking lever, countering the force of the springs.
I’m starting a new production phase that I call “putting things together” – making a compressor assembly and producing parts for it.
duskwight
duskwight,
You are on a journey, young man. You are going where very few have gone before. Building your own air rifle is amazing. Building a recoilless design of your own invention is remarkable!
I just hope you are taking this all down on video, so we can watch it in You Tube sometime soon.
B.B.
I just got word that Karl Kenyon had passed away today, the 31st of July.
Reportedly the funeral will be in Eley on Friday the 11th of August.
I was very fortunate to have been provided with used Anschutz 1413 that came with a Kenyon trigger when I was only around 15 years old. I had good success with that rifle at a very young age. That trigger was a detail that mattered.
I remember when electronic triggers first started showing up in then ISU (now ISSF) matches, Kenyon triggers were the only triggers worthy of comparison. Karl Kenyon was similarly famous, and respected for pretty much everything he did, including barrels.
Although Karl retired over a decade ago, the sport of competitive marksmanship has lost an invaluable member of this community. He was, I believe, a national treasure, as many national records, world records, national championships, and world class championships were won as a direct consequence of work done personally by Carl Kenyon.
God bless you Carl, as we were blessed by your love and devotion to producing the best. The source of all creation is love. I believe that this is what connects us with God. Carl is well connected.
Victor
Karl (not Carl). Sorry!
Tom and Mac, that’s some great shooting with that beautiful model 60! Very impressive and a fitting tribute to the abilities of these wonderful old rifles.
Needless to say I’ve really enjoyed this series on the old-time paper-punchers…time to bring back the HW 55 CM! 🙂
Mike,
It’s in the que.
B.B.
Thanks for the report about D60!
I think there are two reasons why these guns has so good precision even though it’s a break barrel. The first is that it is recoil free. The reason is actually not that it has two pistons, but rather that the rear piston is slightly lighter, and the rear piston has a hole drilled corresponding to the weight of the bullet.
When the pistons move the difference in piston weight pushes the gun forward, and at the same time the accelerating bullet pushes the gun back. These two forces are equal and moving towards each other and that’s what makes the gun recoil free.
The other factor is that Diana 60 has a Scharnier ring (pos. 1/6 in expl. view), which pushes the barrel in the fork to the opposite side. This Sharnier ring is also a type of spring, pushing the barrel to the large washer on the opposite side. By using a Scharnier ring the barrel can not move sideways and will be fixed horizontally.
All the Diana rifles with Giss’ systems had a muzzle velocity according to spec. of 175 m/s. (575 fps). That’s the limit for air guns in Germany, and in Germany all guns must have an “F” in a pentagon to indicate that the muzzle velocity is not higher. This law came 1970, why some older guns may not have this marking (or if they were exported).
Some time during the 70’s Diana changed from seals made of cork to plastic. The old cork seals have in most rifles been replaced with plastic when worn out. I have observed that the plastic seals (when new), often cause quite high friction to the cylinder walls, and this will of course result in lower muzzle velocity. When the springs are new their length is 42cm. I have found that if the springs never have been replaced they are around 40cm. Perhaps it affects the muzzle velocity some, but not much.
/ Micke
/Micke,
You obviously know your Giss system guns. Thank you for your insights and for all the good data you have shared.
B.B.
You’re welcome. A problem here in Sweden was that it it costed more than the gun was worth to have them re-sealed.
I hate to see these fine guns thrown away just because they are a little complex to fix, so I started to repair them free of charge about three years ago. The owner of the gun pays the parts and the transport, but the job is free. You got to have some hobby, right?
A common problem fixing them is that “someone” has poured oil into the cylinder through the transfer port. This as “artificial breathing” when the cork seals are worn out. This gives a black mixture of old cork particles and oil residues in the bottom of the cylinder. This is hard to remove, but must be removed since it will stop the movement of the pressure piston before the end position. I assume that replacing seals and leaving the dirt in the cylinder even can damage the gun (cogs and cogwheels).
If you try to fix these guns; make a spring compressor of the same design as in the manual I wrote for D60. In the original manual a special tool is mentioned, but it is practically useless. There is no way you can compress the springs and at the same time insert the cogwheels. Even if you are two to do the job. Observe the long rod. It is made of steel and has a diameter of 3.5mm. Before you start compressing the springs, it is pushed all the way to the front piston, and through the spring guide (no 28 in expl. view). It will prevent the springs from curving to the sides when you compress them.
…and never use tools to get the small caps with the cogs in the right position. You will damage the fine treads. To get the cogs in the right position can take 30 seconds – or one hour.
@ B.B.
There is another intelligent thing about the D60 you may not have noticed. Back in the 50’s and 60’s the factories making air guns had special tools for bending the barrel straight. They did this manually and with “by eye” looking through the barrel and then manually using the tool to get it straight. I am not sure what is used today, but it can be that this is still in use.
The smart thing with Diana 60 is that it has a metal cover around the thin barrel which is inside. When you tighten the round nut at the front end of the barrel you stretch and straighten the inner barrel. The result is that you get a perfectly straight inner barrel, and that’s what the bullet goes through.
It’s not high-tech, but an elegant and smart way to solve a technical problem. And this was constructed 50 years ago, I assume by Kurt Giss.
/ Micke
/Micke,
Barrel-bending machines are very old in the gun business. Weihrauch still uses tham to straighten their airgun barrels.
And the tensioned barrel like you describe has becomes all the rage in the world of .22 rimfires. Today it’s a carbon fiber jacket around the inner liner, but the tensioning is the same.
B.B.
@ B.B.
Yep, I saw that Weihrauch still uses it in a Youtube clip. But it is an elegant and smart solution to stretch the barrel in a cover around it.
The question is if someone invented it before Diana (I assume Kurt Giss), did. I checked the patents issued in the US, and I am really impressed. We are back some 40 years…and those intelligent mechanical constructions is really something, just simple and elegant.
If I had a mechanical workshop, and the time, I should have tried to make a gun with the pistons moving towards each other, recoil-free, as described in the patent. But….
/ Micke
/ Micke
Not sure when they started, but the Dan Wesson .357 revolvers I’d seen in the late 70s essentially used the system. Allowing for development and tool manufacturing, probably early 70s if not late 60s.
Dan Wesson revolvers were designed for interchangeable (length, not caliber) barrels and shrouds. One screwed the barrel into the frame (using a feeler gauge to set cylinder gap), slid on the appropriate shroud carrying the front sight, and then spun down and tightened a nut onto the muzzle end of the barrel — putting the barrel under tension.
http://www.thehighroad.org/archive/index.php/t-125409.html
/Micke,
Did you know that duskwight is doing just that? He is a blog reader living in Moscow and he is building a Whiscombe-like rifle with dual pistons. You should post to the current day’s blog, then you would get to know everyone and what they are doing.
/blog//
B.B.