Posts Tagged ‘Hy-Score 810’
Diana model 60 recoilless target rifle: Part 3
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.
Diana model 60 recoilless target rifle and HW 55CM: Part 2
by B.B. Pelletier
Announcement: Brendon Krahn 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.
Brendon Krahn is this week’s Big Shot of the Week. He’s sniping at starlings with his .177 Remington NPSS.
Photos and test results for the Diana 60 by Earl “Mac” McDonald
The Diana model 60, which is a Hy-Score model 810 in this case, is a breakbarrel target rifle from the 1960s and ’70s.
That’s right, sports fans, today you’re getting a twofer. For the benefit of our readers outside the U.S., a twofer is slang that means “two for the price of one.” I decided to report on both Mac’s Diana 60 velocity test and my HW 55 Custom Match velocity test for reasons I will explain in each part. Grab a large cup of coffee and an extra Danish and sit back!
The Diana model 60 target rifle
We’ll look at Mac’s rifle first. Today, I’ll reveal the one thing that’s been troubling Mac about his rifle, so it doesn’t take a detective to know that it has to do with velocity.
The cocking effort of his breakbarrel rifle is 28 lbs., which seems high to me. Mac says it doesn’t feel that high because, for some reason, it gets lighter toward the end of the cocking stroke. He also cautions us to beware of the rack-and-pinion noises that these guns have when they’re cocked. To all that I have to say this.
There shouldn’t be any noises when this rifle is cocked. I’ve owned several Giss-system rifles and pistols and shot a lot more, and none of them made any extra noise when they were cocked. That’s clue No. 1. And, I’ll explain how the Giss system works next.
Clue No. 2 is the lighter cocking effort toward the end of the stroke. That’s atypical for a breakbarrel, but Diana has the reputation for breaking mainsprings. When they do, they get smoother. They don’t make any noise, nor do they bind during the cocking stroke. I’ve certainly seen a half-dozen Diana rifles with broken mainsprings and they all acted this way.
How the Giss contra-recoil system works
The Giss contra-recoil system consists of two pistons connected to each other. The real one goes forward when the gun is fired, and a dummy travels to the rear at the same time. The real piston is the only one that has a piston seal, and it’s the one that compresses all the air for the shot. The dummy piston has no seal and is just there to provide an equal and opposite reaction to the real piston. When the real piston slams to a stop, the dummy piston does too at the same instant. The EFFECT of this is that the impulse of each piston cancels the other. The first time an airgunner experiences it he’s usually blown away because, when the gun is timed right, absolutely no firing pulse can be felt.
Of course, timing is the principal concern in a gun that uses the Giss system. That’s why I never recommend a person try to repair his own gun. Sometimes, a mechanical genius like Nick Carter who writes Another Airgun Blog will be able to dive right inside a Giss gun and find no obstacle he cannot understand and overcome, but the average person will just create a basket case.
Looking straight down on the top of the model 60 action, we can see the two telltale caps that cover the gears connecting the two pistons to each other. All Giss-system guns have these caps.
This simple graphic shows how the two pistons oppose each other.
Velocity test
I’ll tell you right now that Mac experienced lower velocity than he expected from this rifle. An Air Rifle Headquarters catalog (the original company) from 1973 gives the velocity of the model 60 as 546 f.p.s., without specifying what pellet was used. That would probably translate to about 550-570 f.p.s. with the pistol-weight target pellets we use today. Mac wasn’t getting that.
He asked me what I thought about putting a drop of silicone chamber oil through the air transfer port to lubricate the piston. We know that these older target spring guns came with seals that dry-rotted over the years, and chamber oil will speed up their demise, but I figured he had to find out somehow, so he did it. But it didn’t cause the seal to destroy itself. It simply boosted the velocity about 12 f.p.s. with no change in how tight the velocity spread was.
The first pellet he tried was the H&N Finale Match Rifle pellet that weighs 8.18 grains. They averaged 457 f.p.s., with a 22 foot-second spread from 445 to 467 f.p.s. The average muzzle energy was 3.79 foot-pounds.
Next, he went with a domed pellet. JSB Exact Diabolos are domed pellets that would not normally be fired in a target rifle unless the target was something other than paper. But Mac also uses his target rifles for mini sniping, so he tested this 8.4-grain pellet anyway. It averaged 474 f.p.s., with a 16 foot-second spread from 465 to 481 f.p.s. The average muzzle energy was 4.19 foot-pounds.
The final pellet Mac tried was the old standard RWS Meisterkugeln pistol-weight wadcutter. Today, they only weigh 7 grains, but Mac had some older ones that weighed 7.7 grains. They were a very loose fit in the breech and averaged 458 f.p.s., with a whopping 37 f.p.s spread from 442 to 479 f.p.s. The average energy generated was 3.59 foot-pounds.
Conclusions
Both Mac and I think the rifle isn’t performing up to spec. Mac found some stated velocity figures of 460 f.p.s. in print somewhere, but he thinks it’s a transposition of 640 f.p.s., which is where a few of the 1960s and ’70s-era target rifles were.
I now believe the rifle has a broken mainspring. Mac thinks it’s just a tired one. Either way, the thought that his gun isn’t performing up to snuff is getting under his skin, so I advised him to have it repaired by either Pyramyd Air or Umarex USA so he’ll know for sure.
Nevertheless, the rifle still shoots as it should and there will be a part 3 coming soon. Let’s go to Part 2 of the other target rifle on today’s menu.
The HW 55 CM target rifle
Is this Custom Match the best HW 55 ever made? Read the report to find out.
I’m putting this additional report here for a couple reasons. First, I didn’t want to go too long without reporting on it. More importantly, I thought I might have to do an extra report on this rifle. As luck would have it, that’s how it turned out. While this is Part 2 and a velocity test, the next part will also be about velocity.
Remember that the HW 55 CM was the rifle that I felt had a harsh firing cycle back in Part 1. After I tightened the stock screws, some of the harshness went away. Even after that, the rifle was still feeling harsher than I felt it should for what it is.
Several of you readers thought that when the gun went back to Beeman for a rebuild, they probably installed the upgraded HW 50 sporter mainspring that would have boosted the power. The only way to find that out is with a chronograph, so that’s what I did. According to Air Rifle Headquarters catalog data, once again, a regular HW 55 should shoot H&N pellets at 650 f.p.s. Unfortunately, they don’t give a lot more data about the specific pellets they used for the test.
The rifle does still shoot a little harsh. When you’re peering through a peep sight, the smallest recoil becomes instantly noticeable. In this rifle, it’s unpleasant. The peep comes straight back and bumps into my skull when I fire. My Ballard rifle does the same thing, only its peep is on a tang sight that collapses forward when it contacts my eye. The HW 55 sight, in contrast, remains rigid and allows me to absorb all the impulse of each shot. Well, I’ll be danged if I’m going to put up with that!
The plan is to quiet the shot cycle with black tar, if possible. If the gun has extra velocity it doesn’t need, I’ll be only too happy to do that.
The cocking effort is just 20 lbs. on the nose, and the ARH catalog says to expect a weight of just 15 lbs. There’s another small deviation from what would be expected. Even the HW 50 mainspring isn’t that powerful, and the long almost-18.5-inch barrel may be providing the extra leverage to reduce the force.
The first pellet I tested was the RWS Hobby, that standard candle of high-velocity lead pellets. At just 7 grains, it’s not only light, but often it turns in surprisingly good results downrange. Hobbys averaged 694 f.p.s., with a 17 foot-second spread that went from 684 to 701 f.p.s. The muzzle energy is 7.49 foot-pounds. I would love to say that this speed wasn’t expected, but it wasn’t far enough out of line to be definitive.
Next, I tried H&N Finale Match Pistol pellets. They weigh 7.56 grains. They averaged 632 f.p.s., with a 14 foot-second spread from 625 to 639 f.p.s. The average muzzle energy was 6.71 foot-pounds. That seems right on the money for a stock mainspring.
The final pellet I tried was the RWS R-10 Match Pistol pellet. Although they’re just as light as the Hobbys, they go the same speed as the heavier H&N Match Pistol pellets. That would indicate a bore-fit issue.They averaged 632 f.p.s., with an 18 foot-second spread from 619 to 637 f.p.s. The average muzzle energy was 6.21 foot-pounds.
Evaluation
I can’t tell for certain that the mainspring has been upgraded, but I do know that the rifle has way more velocity than I need. The next step is to lube the spring with black tar to see what EFFECT, if any, that has on the shot cycle. While Mac wants more velocity, I’m looking to get rid of some for the sake of smoothness.
I’ll break these two reports into separate reports for their respective accuracy tests. But before I do the accuracy test with the HW 55 CM, I’ll lube the spring and retest the velocity results, giving this rifle one extra report.
Diana model 60 recoilless target rifle: Part 1
by B.B. Pelletier
Announcement: Cristal Lopez is this week’s winner of Pyramyd Air’s Big Shot of the Week on their facebook page. She’ll receive a $50 Pyramyd Air gift card.
Cristal Lopez is this week’s Big Shot of the Week. She got a chance to shoot her brother’s TX200 Mark III.
Photos and test results by Earl “Mac” McDonald
I had fully planned on testing the velocity of the HW 55 CM for you today, because so many of you indicated an interest in the gun in Part 1. In preparation for that report, I test-fired the rifle against both my HW55 SF and my Walther Olympia LGV, and the results were not what I expected. First, I discovered that the stock screws on the 55 CM were loose. Wouldn’t you know that when I tightened them, the gun vibrated less than before? But the firing cycle still felt a little harsh, so I then fired both the 55 SF and the LGV alongside the 55 CM for a comparison.
As things turned out, the 55 SF recoils about the same as the 55 CM (now that the stock screws are tight), but the SF buzzes a lot more than I remembered. Instead of shooting what I’d remembered as a “perfect” rifle (the SF), I discovered that I probably need to do something about the powerplant in that rifle, as well.
Then, I shot the LGV. It recoils a lot less than the 55 CM, but you would expect that from a rifle that’s several pounds heavier. However, the LGV also buzzes just a little, so it isn’t the sweetie that I remember, either. It’s not enough to do anything about, but it’s still not the perfectly smooth rifle that I remembered it being. Apparently, the tune that Beeman did on the CM was a good one, and that put me in a quandary about what to do next.
Here’s what I’ve decided. I will definitely test the velocity of the CM as it is now, but then I plan to open the gun and look inside. I expect to find a synthetic piston seal now that I know Beeman rebuilt the rifle. I’ll apply some black tar to the mainspring to soften the firing impulse. Of course, the rifle will be tested once it’s buttoned up again. You’ll have a positive before and after velocity test, plus we’ll all learn if the mainspring inside is an upgraded one or not and if the piston seal is synthetic.
That’s a lot of work, though, and I’m not prepared to do it for today’s report. But Mac just finished testing a Diana model 60 target rifle, so I’m starting that report today.
Mac owns a Hy-Score model 810, which translates to the Diana model 60 recoilless breakbarrel spring-piston target rifle. Diana made several breakbarrel target rifles on what is known as the Giss contra-recoilling piston system that cancels all recoil. I will cover how the Giss system works in the next report, but our Russian blog reader, duskwight, knows all too well how it works, as he’s designing something similar for himself.
Besides the model 60, they made models 65 and 66, both of which have a barrel locking lever to hold the barrel positively shut when firing. The model 60 is the only one of the three that doesn’t have that latch. The model was made from 1963 to 1982, and Mac’s was produced in February 1967.
The Diana model 60, which is a Hy-Score model 810 in this case, is a breakbarrel target rifle from the 1960s and ’70s.
Can a breakbarrel rifle be accurate?
You know, whenever that question is asked, the Diana Model 60 is the rifle I use to answer it. Since the sights are not both (front and rear) mounted to the barrel, the breech joint does come into play! I won’t string you along on this question. Yes, a breakbarrel air rifle can be just as accurate as a fixed barrel air rifle, and Mac will prove it to you in Part 3 of this report.
The Diana 60 uses just a single ball-bearing detent to close and lock the breech in position. It’s the same design that many of their sporting spring rifles of the same era use. Apparently, it works quite well. How well? You’ll have to wait to see.
Description of the rifle
The model 60 is heavy, at about 9.5 lbs. It’s all wood and metal. The only plastic to speak of are the trigger and triggerguard. The rifle spans 43.5 inches, of which 18 inches make up the barrel. The Hy-Score version of the rifle came with a steel barrel jacket for added weight. The length of pull is 13.5 inches, which Mac finds perfect.
The bluing is deep and flawless — what would be found on airguns costing over a thousand dollars these days. The wood stock is checkered with hand-cut diamonds. Of course, the gun was made in the days when human labor was still affordable, so that isn’t such a surprise.
Generous checkering on the flat bottom of the forearm.
All checkering is hand-cut.
The depth of the stock makes it possible for the cocking lever to be one piece and still have a short cocking slot. This would reduce vibration if there was any, but Mac assures me there isn’t. He says it’s difficult to tell when the gun has fired, because it’s so smooth.
The cocking link is one piece, but the depth of the stock allows the cocking slot to be short. This adds to the stability of the rifle.
Mac is very taken with the obvious quality of this rifle. He scrutinized the smallest details, and though I won’t show you all of them, perhaps just one will give you the sense he is trying to convey in his report. The pivot bolt is locked down by a screw that intersects the larger bolt head on its periphery. Many rifles have this, including the Slavia 631 and even the Diana sporting rifles, but few of them have a total of 11 cutouts for the locking screw to intersect with!
It’s a small detail, but Mac feels it conveys the overall quality of the airgun. The barrel pivot bolt head has 11 cutouts on the periphery for the locking screw!
Mac can’t stop talking about the trigger on this rifle, and you must remember that he owns 7 FWB 300 rifles to compare it with. He says it is so delightful that he doesn’t want to adjust it, though it allows for plenty of owner adjustment.
Since the Hy-Score 810 was sold by Air Rifle Headquarters (the original one) back in the ’60s and ’70s, I have a catalog description of it from contemporary times. The next report will have a little more history from this material.
