Posts Tagged ‘JSB Diabolo Exact Jumbo Express pellets’
by Tom Gaylord, a.k.a. B.B. Pelletier
Wow! That’s my assessment from today’s test. Please read the explanation of how I arrived at that result.
Today, I shot the .22-caliber Walther LGV Challenger air rifle at 25 yards with open sights. You’ll remember that it has fiberoptics front and rear, but they can be defeated by lighting the target brightly and sitting in a dark place to shoot. Fiberoptics are not good sights for precision shooting, but they’re good for a fast snap shot when hunting. These can be used both ways, so they’re wonderful.
I always become concerned when I shoot indoors at 25 yards — especially when using open sights. I have only a few inches of clearance through the garage door; and if a pellet goes astray, it could plow into the woodwork around the door. I needn’t have worries with the LGV, however, because the only place those pellets went was to the target.
JSB Exact Jumbo Heavies
Reader Kevin asked me to try the rifle with 18.1-grain JSB Exact Jumbo Heavy pellets, so I did. I was concerned that a 12 foot-pound rifle wouldn’t be able to handle a pellet so heavy, but that wasn’t a problem. In fact, this pellet gave me the best 10-shot group of the test, measuring 0.78 inches between centers. That’s just a hair over 3/4 of an inch!
Ten JSB Exact 18.1-grain heavies made the best group at 25 yards. It measures 0.78 inches between centers. This is great for 10 shots at 25 yards with open sights.
The first group was low on the target, so the rear sight was adjusted up for the next pellet, which was the 14.3-grain Crosman Premier. As you can see, I lucked into the perfect sight adjustment for this pellet and tore out the center of the bullseye. I realize this makes a lot of people feel better about the group, but I hope you readers realize that it’s simply a matter of sight adjustment that determines where the pellets land. If the gun will shoot a tight group, then you can move that group anywhere you want. This one certainly does shoot very tight.
Ten Premiers landed in a group that measures 1.147 inches between centers. It’s not as tight as the previous group, but we expect that to happen with different pellets. The irony is that because this group is centered on the bull, it’ll look better to those who think the object is to the strike the center of the target regardless of anything else.
Ten Crosman Premiers made a 1.147-inch group. It happens to be centered on the bull but isn’t as tight as the previous pellet.
Predator Big Boy
I did try a group of 10 Predator Big Boy pellets in the LGV; but at 26.2 grains they’re clearly too heavy for this powerplant. They opened to 1.657 inches at 25 yards, which told me this isn’t the right pellet for this rifle. I could also hear a very long lag between firing and the pellet hitting the trap, so the velocity must be in the high 300s or low 400s.
Ten Predator Big Boys made an open 1.657-inch group. This is obviously not the pellet for the LGV.
JSB Exact Jumbo Express
I finished the test with 10 JSB Exact Jumbo Express pellets that weigh 14.3 grains. I tried it because, in the 10-meter test, 13.4-grain JSB Exact RS domes didn’t do as well as the others. But at 25 yards, this pellet certainly did very well. Ten pellets grouped in 0.786 inches, just a whisker larger than the group of 18.1-grain heavies…and really too close to call.
Ten JSB Exact Jumbo Express pellets made3 a 0.786-inch group at 25 yards. This is too close to the group made by the Jumbo heavies to call the difference.
The bottom line
So far, the LGV is living up to its name and even going beyond. I say beyond because this new LGV delivers 12 foot-pounds, where the target rifle by the same name was less than half that powerful.
This rifle is smooth, it holds well, the weight is distributed very well and the trigger is light enough for good work. When you cock the rifle, it’s smoother than any breakbarrel I’ve ever tested…other than a few that were tuned to perfection. I had the chance to shoot another LGV while I was at Umarex last week, and it felt identical to the rifle I’m testing. Rick Eutsler, who usually tests airguns costing $200 and under, fired the rifle before he was ready on the first shot. He, too, was blown away by the feel of the gun.
I know these rifles are going to cost a lot, and I know that not everyone will be able to purchase one, but that doesn’t detract from the fact that this is the best new breakbarrel to come along in the past half-century. I may not live in a mansion, but that doesn’t prevent me from appreciating one when I see it.
by Tom Gaylord, a.k.a. B.B. Pelletier
The Diana 25 (this one says Winchester 425) was made for decades. It is at the top of the youth line of air rifles from the ’50s through the ’70s.
On Friday, I tested the Chinese Fast Deer sidelever rifle at 25 yards, and in doing so I started the juices flowing again for the vintage airguns. One remark I made in the report was that I thought the Fast Deer might be more accurate if I fitted a peep sight in place of the open sights that are on it now. That got me thinking about other low-powered spring guns I’ve recently tested — including the Winchester 425, which is a Diana 25 by another name.
I tested the 425 at 10 meters because it has open sights and also because of the low power level. It’s a .22-caliber spring rifle that shoots in the low- to mid-400s, and long-range accuracy is not its strong suit. But after seeing the Fast Deer perform, I began to wonder how the 425 might do if I tried it with a peep sight. Kevin recommended trying it, and I was happy to take his suggestion. We always talk about how peep sights improve the aiming situation, so a peep sight ought to have some impact on even a rifle like this one.
As it happens, I have a peep sight that attaches to the rear sight base on many vintage Diana air rifles, including this 425, so it was easy to remove the open rear sight and attach the peep. I left the open sight in place until the peep was firmly anchored to the base, then I looked through the peep and adjusted it until the open sight picture looked perfect through the peephole. That told me the peep was looking at the same place as the open sight, so no special sight-in procedure was required.
The Diana peep sight fits the model 25 as well as many of the larger models. It looks simple but delivers on target!
The Diana peep sight is vintage and appears less sophisticated than the target peeps we see today; but when you use it, you soon learn that it’s as nice as any of them. It has crisp detents with very visible scales for both adjustments plus the directions are also on the adjustment knobs. They’re in German, though, so they’re the reverse of American adjustments. The sight sits low on the spring tube and is shaped to conform to the contours of all Diana rifles, so there’s very little clearance between the sight and the gun. The sight does extend back, which is helpful, but as small as the 425 is, I still found it difficult to get as close to the eyepiece as I would have liked. That’s because the stock’s pull is a sporting length instead of a target length that would be several inches shorter.
JSB Exact RS
Since JSB Exact RS domes had proved to be very good at 10 meters, they were the first pellet I tried at 25 yards. I trusted that the pellet would go to the point of aim and it did. The first shot was right on target, but there was a small problem because I was trying to use 10-meter rifle targets and the bull is too small for me at 25 yards. So, I replaced the target with a 10-meter pistol target and afterward everything was fine.
The first group of 10 pellets measures 1.059 inches between centers. Now, that sounds like a big group; but if you look at the target, I think you’ll see that it really isn’t so bad. Seven of the 10 pellets landed in 0.545 inches and that’s good.
Another pellet that did relatively well in the 10-meter test was the RWS Superdome. And this is where the difference between 10 meters (11 yards) and 25 yards really shows! Ten Superdomes went into 1.349 inches, and the group appears scattered left and right. This is not a pellet I’d use in this rifle at this distance.
Here is another example of why a 10-shot group is so much more valuable than several 5-shot groups. You could get lucky with several 5-shot groups and never know how well the rifle really shoots, but a single 10-shot group tells the tale very clearly. In the end, it saves time and pellets.
Notice that Superdomes struck the target lower than the JSB RS that preceeded them. So, I adjusted the rear sight to hit higher on the target following this test.
JSB Exact 14.3-grain domes
Next, I tried some JSB Exact Jumbo Express 14.3-grain domes. Since the RS pellets had done so well, I thought these might do well, too, even thought this pellet has disappointed me very often in the past. For some reason, the RS and 15.9-grain pellets shoot rings around this one, and I don’t quite know why.
The Diana 25 doesn’t like them, either. Though the group is well-rounded, the shots seem scattered within it. The group measures 1.288inches between centers and there is nothing to give much hope of any better performance.
At this point in the test, I was starting to lose confidence in the rifle. True, the RS pellets had shown some promise and deserved another chance, but instead I had a thought. What about Crosman Premiers? I normally don’t shoot Premiers in vintage Dianas because I like to use only pure lead pellets, but it sounded like it was worth a try.
The pellets loaded snugly into the breech, but they weren’t quite what I would call tight. The firing behavior, though, was quite different from all the other pellets I’d shot in the gun. It was harsh and a bit buzzy, which tells me the powerplant isn’t being cushioned sufficiently by this pellet.
Down at the target, though, the story was quite different. Premiers made the second-tightest group of the test and were so good that they looked like they warranted a test all their own. The vertical dispersion was 1.09 inches between centers, which is slightly larger than the group made by the JSB RS pellets. The lateral dispersion was only 0.491 inches! And the group was way below the bull, meaning that this pellet dropped many inches from the impact point of all the others. In fact, I’m not certain that all 10 shots landed on the paper because the ragged hole they tore doesn’t tell me how many pellets passed through. It just looks like they all went there.
Crosman Premiers also made a large group, but they were tight side-to-side. This is a pellet to consider further! Sideways dispersion is the gun’s fault. Vertical error is more of an aiming issue or perhaps a wild velocity variation.
Premiers struck the target much lower than the JSB pellets before them, so the feeling upon firing is also evidenced in the velocity. Remember, I’d already adjusted the rear sight higher to compensate for the Superdomes, so this second adjustment jacked it up a lot from where we started.
Observation thus far
The addition of a peep sight to the Winchester 425 was a great idea. It took an accurate and easy-shooting rifle and stretched the useful range many times. I don’t know that a scope would give results that are any better, though it might be fun to try!
by Tom Gaylord, a.k.a. B.B. Pelletier
The Diana 25 (this one says Winchester 425) was made for decades. It’s at the top of the youth line of air rifles from the ’50s through the ’70s.
Today, we’ll learn how accurate a vintage Diana model 25 breakbarrel air rifle, in the form of a Winchester model 425, can be. I have to tell you, days like this are pure candy to me! Shooting a smooth vintage air rifle is so relaxing. Since they’re no longer sold, I don’t have to scramble to shoot my best, because only a collector will ever buy one. On the other hand, these lower-powered spring guns mostly out-shoot the modern guns anyway, at least at short distances, so even shooting relaxed I do pretty well.
We all agreed that the model 25 is a close-range plinker, so I shot from 10 meters. I used a 10-meter pistol bull since I was using the open sights that come with the rifle. By strongly lighting the target and keeping the room I’m shooting in dark, the sights appear sharp against the target. I normally don’t like the German Dachkorn-type front sight, which is a V-shaped post; but under these circumstances, it worked very well. Incidentally, I’ve always referred to this as a Perlkorn; but while researching this report I discovered that the Perlkorn has a bead on top of the tapered post.
Sitting down at the bench to shoot reminded me of just how easy this little rifle is to cock. The barrel goes down butter-smooth, and it takes only about 14 lbs. of force to do it. But when I brought it back up after loading, I discovered that the pivot bolt was a little loose. The barrel wouldn’t stay in one position after the rifle was cocked. It flopped back down again. That’s a sign that the pivot is too loose, which leads to a loss of air at the breech. I decided to tighten it, and that lead me to another wonderful feature of the Diana 25 — the pivot bolt has a locking screw!
The head of the barrel pivot bolt (larger slotted head in the photo) is cut out around its edge to receive the smaller head of the locking screw. Once set, this bolt will not get out of adjustment.
The pivot bolt has cutouts around its edge to accept the head of a smaller locking screw. Once you set the bolt where you want it, put the locking screw in and the setting will never move. This is one of those seemingly insignificant features that we overlooked when rifles like this were new, yet today even the most expensive pellet rifles don’t have it! In fact, a good number of the current guns don’t even have a pivot bolt — they use a plain pin that can never be tightened.
The first pellet I shot was the .22-caliber RWS Superpoint. I mentioned in an earlier report that I like the Superpoint for its thin skirt that gets blown out into the sides of the bore when the rifle fires. Other pellets are either too hard, or their skirts are too thick to deform with the relatively light puff of air from the model 25’s piston. The Superpoint, though, should work well in a gun like this.
The distance was 10 meters and I shot from a rest, so this report is about the rifle’s capability and not the shooter’s. That crisp ball-bearing sear was a real pleasure to use, and I didn’t waste a lot of time setting up each shot.
I used the sights exactly as they were set when I got the rifle. Remember that my friend Mac was the former owner, so it came as no surprise when the pellet landed exactly at the aim point — a 6 o’clock hold on the bullseye. After seeing the first pellet was where it needed to be, I didn’t look at the target again until the 10th shot had been fired. What I saw then was a surprise — even when I had been expecting good results. Ten RWS Superpoints went into a group that measures 0.613 inches between centers. It’s a one-hole group that looks smaller than it really is because the pointed pellets allowed the paper to return to its normal dimensions after they pass through. This is the same kind of accuracy I used to get from the Hakim trainers at the same 10 meters.
Ten RWS Superpoints made this 0.613-inch group at 10 meters. It’s larger than it looks because the paper flapped back after the pellet passed through.
The next pellet I tried was the RWS Hobby. This is another pellet that’s often very good in rifles that shoot at lower power. And by being fairly light, at 11.9 grains, it has the advantage of traveling faster than most other pellets. Ten Hobbys grouped in 0.538 inches between centers. It was another one-hole group. Nothing to do but to smile and hope the rifle continues to shoot like this!
Ten RWS Hobbys are even tighter, making this 0.538-inch group.
The last pellet I tried was the JSB Exact RS dome that weighs 13.4 grains. I hoped that this pellet might shine in the little 25 in the same way the .177 version does in my Beeman R8. Well, shine it did, putting 10 of them into a group that only measures 0.38 inches between centers. Does that explain why I like shooting these little vintage spring guns so much?
The JSB Exact RS dome was the best pellet of all. Ten made this 0.38-inch group at 10 meters.
The Diana breakbarrels all have slanted breech faces; and when the barrel is closed, if the pellet isn’t seated flush all the way around the skirt, it can catch on the action and slightly bend the rim of the skirt when the barrel’s closed. This was happening with all three pellets used in this test. So I shot a fourth group of 10 with the most accurate pellets (JSB Exact RS) seated deep in the breech. I wanted to see what effect this would have, if any.
Because the breech face is slanted, the tip of the pellet skirt sticks out like this when the pellet is seated.
When the breech is closed, this is what happens to the pellet. It doesn’t seem to hurt accuracy.
Seating pellets deep in the breech (JSB Exact RS used) opened the group up and also dropped the point of impact about one inch at 10 meters.
Deep-seating didn’t work this time. The group of 10 JSB Exact RS pellets opened to 0.615 inches. It also dropped the point of impact about one inch at 10 meters. Doesn’t seem like it’s worthwhile.
I sure hope this isn’t the last report I get to do on this air rifle. What a joy it is to shoot something that’s accurate, has a great trigger, is quiet and is easy to cock. I know you have to buy these used, but it’s worth the effort, in my opinion. It doesn’t replace your modern magnum air rifles, but it gives you something to do when you just want to shoot without a lot of fuss. If you’ve enjoyed reading this report, remember that there are three different models of the Diana 25. Only two of them have the ball bearing sear, so be careful when you look for one.
by Tom Gaylord, a.k.a. B.B. Pelletier
The Diana 25 (this one says Winchester 425) was made for decades. It’s at the top of the youth line of air rifles that were made from the ’50s through ’70s.
Today, I’ll test the Winchester 425 (Diana 25) breakbarrel air rifle for velocity and power. When I shot the rifle, the ultra-smooth firing behavior suggested that it might have been tuned. And a faint whiff of burned grease confirmed it. I shined a tactical flashlight down into the cocking slot and saw the mainspring is coated with a thin layer of black tar — proof positive the innards have been breathed upon!
The second clue as to its past is that the rifle was owned by my friend Mac before I got it. I know he loves this platform and does not fear taking one apart to make it better.
Finally, the trigger is adjusted to perfection. Mac knows how to do that, as I described in Part 1 of this report. The trigger is two-stage with a very long first stage that stops at a definite second stage before breaking crisply at the shot. I would not call it a glass-rod trigger, because the excessive overtravel after the trigger breaks makes it feel less precise than it really is, but if you’ve never sampled a fine sporting airgun trigger, this one would amaze you. The only aspect that might put some people off is that the first stage has to be very long for the second stage to be crisp. You can try to shorten stage one if you like — but then stage two disappears, and the trigger becomes a guessing game.
The trigger return spring on this rifle is heavy enough to give the first stage a 1 lb., 1 oz. pull weight. Stage two breaks at 2 lbs., 15 oz., and I doubt you’d guess it to be that much.
One reason I love little breakbarrels like this model 25 is their light cocking efforts. This rifle has a ball-bearing detent that makes the barrel break open easier. Then just 14 lbs. of force are needed to cock the rifle. That’s so little that pre-teens will find it easy. Of course, this particular example is as smooth as they come because of the tune it’s received, but even a rusty old relic that’s been sitting up in the loft of a barn for 30 years will still cock pretty easy.
Instead of a chisel detent that has a powerful spring behind it, the Diana 25 barrel is held closed by a spring-loaded ball bearing. It is much easier to open and close the barrel, yet it stays shut when the gun fires.
Remember, this is a .22-caliber air rifle — not a .177. This is a case where the smaller caliber probably would have been the better choice, but folks with large fingers will still appreciate this one for the ease with which it can be loaded.
The first pellet I tested was that old standby — the RWS Hobby. In .22 caliber, this wadcutter weighs 11.9 grains and typically offers the highest velocity of any of the lead pellets. In the test rifle, Hobbys averaged 440 f.p.s. The spread went from 421 to 458 f.p.s., which is a fairly broad 37 f.p.s. range. They loaded firm, as if fitting the bore well, so I expect them to do well in the accuracy test. At the average velocity, Hobbys generate 5.12 foot-pounds of muzzle energy.
From what we learned while testing the Hy Score 801 rifle that has a pellet seater built into the barrel, deep-seating pellets can sometimes increase velocity and also stabilize the overall range of velocities achieved. I tried seating the Hobbys deep into the breech. The result was a large loss of velocity — from 382 to 408 f.p.s. for the deep seating! That tells me the model 25 doesn’t like its pellets seated deep, so I didn’t try it with the other pellets.
JSB Exact Jumbo Express
The next pellet up was the JSB Exact Jumbo Express dome that weighs 14.3 grains. This is a pure lead pellet, and it fits the rifle’s breech very nicely, going in easier than the Hobbys. These averaged 417 f.p.s. and ranged from 414 to 422 f.p.s. That’s an incredibly tight 8 f.p.s. spread across 10 shots! I want to note that this pellet also went deeper into the breech with just finger pressure. That means the skirt was not subject to damage when the breech was closed — something I can’t say for the other two pellets I tested. This pellet produces 5.52 foot-pounds of energy at the muzzle.
The last pellet I tested was selected for a very specific purpose. I’ve found in the past that taploaders that have large holes through their taps — such as the Hakim trainer — need a soft lead pellet with a very thin skirt so the light air blast will flare the skirt out to contact the bore and seal it against air blowby. Even the RWS Superdome has a reinforcing ledge inside its skirt that prevents this from happening. But the RWS Superpoint doesn’t. The Superpoint skirt is very thin, soft and pliable; and it seals better than any lead pellet I’ve ever used. I like to at least try them in low-powered spring guns like this model 25 air rifle because they often give very good results on paper.
In the test rifle, Superpoints averaged 377 f.p.s., and the spread was from 373 to 383 f.p.s., so only 10 f.p.s. The Superpoint weighs 14.5 grains, so at the average velocity the muzzle energy was 4.58 foot-pounds. With the first two pellets as a comparison, I wouldn’t call this a great performance.
How does the 25 compare to the Diana 27?
For no better reason than the fact that I was curious, I then tested my Diana 27 (Hy Score 807) with the same pellets. I figured it would be a little more powerful than the 25, but not a lot.
Where Hobbys averaged 440 in the 25, in the 27 they went 495. The JSBs that averaged 417 in the 25 went 449 in the 27. And the RWS Superpoints that only went 379 in the 25 actually went 458 in the 27 — exceeding the JSB pellets! I think that result was that thin soft skirt kicking in, and the 25 probably doesn’t have quite enough power to blow the skirts out like I mentioned.
Impressions so far
I wish this rifle was still being made so more of you could experience it. It’s a delight to shoot. It cocks so easily, and the trigger is a dream to use. Let’s all hope the accuracy is there, as well. I’m not looking for tackdriving accuracy at 25 yards this time — just nice round groups at 10 meters because the Diana 25 is a plinking air rifle — first, last and always.
by B.B. Pelletier
Before I start today’s report I have to share a concern. The other evening while we were watching TV, Edith suddenly suggested that I write an airgun blog for beginners. I thought about it, and I decided she is probably right.
Of course, this very blog is supposed to be for beginners, but I fear that I’ve wandered away from that objective. There’s too much jargon in the articles and not enough explanation. As far as the comments are concerned, I have no problems with what’s said because readers ought to be able to say almost anything. But the articles ought to be more informative and not require an airgun background to understand.
If you’re new to airgunning and have been struggling with this blog, please speak up now. I would like to hear your views on how we can make this blog better and easier to understand.
Okay, on to today’s report, which, if subtitled, would read, BB gets frustrated. I’ve tried to like this Gamo Silent Stalker Whisper IGT. I really have, and I did like many things about it. I liked the light weight, the ease of cocking and the lack of vibration when fired. I didn’t care for the scope Gamo sends with the rifle, but today was supposed to take care of that. But it didn’t work out that way. Instead, adding a better scope only demonstrated that this rifle isn’t going to shoot like it should, and I believe I now know why.
You’ll recall that I criticized the Gamo scope pretty severely, so for today’s session I mounted a Leapers 6-24×50 AO scope in the BKL 1-piece droop compensating mount I’m using to compensate for the rifle’s extreme droop. Blog reader Kevin has said that he wouldn’t buy another Leapers scope because of the way he was treated by the company in what should have been a warranty situation, and I have to agree with him on that; but their scopes are still a very good value for the money. This scope is one I’ve used several times before, and it’s never let me down.
I figured the first thing to do was to verify my zero after changing out the scope, and of course there was a lot of adjustment to be made with the new one. I have no idea what gun or mounts this scope was associated with last, so it will naturally be off unless I get lucky. But this wasn’t the day for luck.
After zeroing, the first pellet I tried was the 14.3-grain JSB Exact Express that looked so tantalizing in the last accuracy test. And this is where the frustration began. In the last test using the poor scope, I managed a 10-shot group that measured 1.267 inches between centers. I expected far better than that, now that I could clearly see the target. But after only seven pellets went into a group measuring 1.479 inches, I knew it was not to be.
I then changed to the heavier 15.9-grain JSB Exact Jumbo pellet. But another seven of those pellets went into a group measuring 1.427 inches, and I stopped wasting my time.
I was really frustrated, because nothing I tried was working. I would get two pellets in the same hole when I tried a new hold, and then the third would land two inches away. This was starting to get embarrassing! And I did try many other pellets, including some that are obsolete, like Beeman Silver Jets. Nothing worked. RWS Hobbys were so far off-target that they put a hole in the aluminum light fixture I use to illuminate the target. And Beeman Kodiaks, which I think are much too heavy for an air rifle in this power class, were doing the same thing as all the rest — grouping two tight and then throwing the next two several inches away. Then I shot another disappointing group of H&N Trophy Hunters.
Finally in desperation I shot a last group of Beeman Silver Bear hollowpoints that ended with the fourth shot. Why shoot any more when four shots already has you over one inch? Look at the group, and you’ll see what I mean.
Now this is the point in many reports where I pull back the curtain and reveal the sunshine of a successful test. But not today. There is no joy in Mudville today. Oh, that’s not true.
I felt so bad about all the lousy shooting, and believe me, there’s more than I’m reporting, that I grabbed my tuned .177-caliber Beeman R8 and shot a final group of ten Beeman Devastators at the same 25 yards. This was to wash the bad taste of this test out of my mouth.
And it worked. Apparently I can still shoot — even on a day when I can’t get the Gamo Silent Stalker Whisper IGT to shoot worth a darn. It just felt good to be able to say that.
So, what’s wrong?
I think I know why the Silent Stalker Whisper isn’t grouping, and there isn’t a darn thing I can do about it. Early on in this second accuracy test, I started grabbing and shaking things to see if anything was loose. When I came to the barrel, it shook from side to side. It wobbles on its pivot, and there isn’t anything I can do about it.
I see from examining the action outside the stock that a lot of thought went into this gun, but they missed a very critical point — the barrel lockup. If that’s loose and can’t be tightened, and apparently it can’t, then the rifle will never live up to its potential. It’s still a nice lightweight breakbarrel with smooth shooting characteristics, but it lacks the all-important accuracy potential shooters want.