Posts Tagged ‘JSB Match Diabolo Exact pellets’
by Tom Gaylord, a.k.a. B.B. Pelletier
Today’s report is a guest blog from duskwight, our blog reader in Moscow. It’s a report of a test to determine if changing the power of a variable scope affects the potential for accuracy
If you’d like to write a guest post for this blog, please email me.
Over to you, duskwight.
How scope power affects accuracy
Hello, my airgunning friends! This is a report of a small test I performed recently to see if changing the power of a rifle scope affects the accuracy potential in any way. I guess the thing I’m testing is if you need to see the target as large as possible for aiming precision, or if you can be just as accurate when it appears smaller, because the crosshairs of your scope will still be in the same place.
B.B. tested this for me last week and reported it in the most recent test of the TX200. He shot two 10-shot groups at 50 yards with the scope set on 4x and 2 more with it set on 16x. In the first set of targets, he admitted that he wasn’t holding the rifle as good as he could and the 16x group was smaller than the one shot on 4x. But in the second set of targets, when he said he tried his best, the 4x group was smaller than the 16x group.
B.B.’s test was shot outdoors with a recoiling spring rifle. I decided to shoot mine indoors with a modified Gamo CF-X spring rifle I built. I call my rifle the Shillelagh, and I’ve taken a picture so you can see what it looks like.
My Shillelagh (Gamo CF-X) was used for this test.
I’m shooting indoors, so wind isn’t a factor. The air is dry and the temperature is 20 degrees C, or 68 F. I am shooting off a soft rest like B.B. used with the TX200. The distance is 50 meters, and my targets are made of 2 black circles, the inner one 1/2″ in diameter and the outer one 1-1/2″ in diameter. I’m measuring the groups from the outsides of the pellet holes farthest apart, and my groups each contain 10 shots.
I decided to select the power settings 6 and 12 magnifications for this test. I shot 2 groups on each magnification. In one set of targets, I concentrated on the hold very much; and on the other set, I went faster, with less concentration. Let’s take a look at the results.
The first group that was fired on 6x with extreme concentration measured 0.906″ across the outside of the group at the widest point. If we use a nominal .177 inches for the pellet diameter, that group would then measure 0.7295″ between centers.
This 10-shot group came with the scope set at 6xr and using extreme concentration. The outside measurement in 0.9065″; and using 0.177″ as the pellet diameter, the center-to-center measurement is 0.7295″. Nice to know my Shillelagh can shoot!
The first group shot with the scope set at 12x and using extreme concentration measured 1.4455″ across and 1.2685″ between centers. That’s quite a bit larger than the 6x group!
This 10-shot group was made with the scope set at 12x and using extreme concentration. The outside measurement in 1.4455″ across; and, using 0.177″ as the pellet diameter, the center-to-center measurement is 1.2685″. Quite a difference from the 6x group.
More relaxed shooting
Now, it was time to shoot groups from a more relaxed rest. I tried just as hard, but things went faster this time. The first group was shot at 6x and measured 1.003″s across the outside. The C-T-C measurement is 0.826″. Also not too shabby!
Here are 10 shots with the scope set at 6x with a more relaxed shooting style. The outside measurement is 1.003″ across, and the C-T-C measurement is 0.826″.
Next, I shot another 10-shot group in the more relaxed style with the scope set on 12x. This group measured 1.7325″ across, which gives us a measurement of 1.5555″ between centers. This is the largest group of the test and more than double the size of the first group shot on 6x.
Ten shots with the scope set at 12x with a more relaxed shooting style measured 1.7325″ across, and the C-T-C measurement is 1.5555″. This is the largest group of the test.
It’s clear to me that lower magnification isn’t any hinderance to accuracy, as long as you can see the target clearly. In fact, I think lower magnification is the way to go.
I made a huge mistake when I edited this text for duskwight. I assumed that his Shillelagh is his recoiless rifle project, when in fact, it’s a highly modified Gamo CF-X. The rifle seen in this test is that Gamo CF-X. I apologize for the confusion this has caused. — B.B.
Some of our newer readers probably don’t know the story of how duskwight built a recoiless spring rifle from scratch. Like you he was a reader of this blog and he was also an airgunner before finding this blog. He knew about the famous Whiscombe rifles, but they were hard to come by — even when John Whiscombe was still making them. Adding the extra difficulty of getting one all the way to Russia made him think about building his own rifle. When he first told us his plans, I thought it would never happen; and he shared all his struggles with unreliable machine shops and companies that could not meet his specifications. It seemed as though it wasn’t meant to be.
But he persisted, and finally, he had a working prototype. It took years of effort…and I don’t want to know how much money. But he did it. Then he sat down and whittled out a stock from a raw wood blank.
This Gamo CF-X, which he calls the Shillelagh, is just one example of his expertise building custom airguns. I think the accuracy he got with it is quite stunning!
Duskwight is Russia’s airgun answer to New Zealander Bert Munro, who took a 1920 Indian motorcycle and modified it into a 200 m.p.h. streamliner in the 1960s! People like this are in extremely short supply, and it’s our honor to know this one!
by Tom Gaylord, a.k.a. B.B. Pelletier
This is my second trip to the rifle range to shoot the TX200 Mark III at 50 yards. Last time, I shot only heavy pellets; today, I’ll shoot the hopefully more-accurate lightweight pellets, plus one JSB medium-weight pellet that several blog readers have had success with.
I also shot the rifle laying across the sandbag, instead of in the long groove down the center. Several readers said that was the best way to rest the rifle directly on the bag.
The day was perfect for shooting pellet guns at long range. There wasn’t a breath of air during the entire session.
The first pellet I tested was the Crosman Premier lite — a 7.9-grain dome that some say is the most accurate pellet of all in the TX200. The group landed about 2-1/2 inches above the aim point because the rifle was still sighted for heavy pellets. But it was centered perfectly, and 10 pellets made a group measuring 1.077 inches between centers. That’s not a bad group, but I’ve seen TX200s do better at 50 yards.
That was a good start. The group was only slightly larger than the smallest group fired in the session before, which was 1.042 inches.
Following the first group, I adjusted the scope down several clicks. I wanted to keep the shots on or near the bull at which I was aiming.
JSB Exact 8.4-grain dome
Next up was the JSB Exact 8.4-grain dome, a pellet that several readers said was the most accurate one in their TX200s. Alas, that wasn’t the case in my rifle. When the first 5 pellets landed in a very vertical 2.40 inches, I stopped shooting. There’s no way the last 5 shots can improve things. Clearly, this isn’t the pellet for my rifle!
JSB Exact RS
The next pellet I tried was one I had high hopes for — the 7.3-grain JSB Exact RS dome. It does so well in so many spring rifles; but, once again, the TX200 Mark III is not one of them. Ten pellets made a group that measured 1.957 inches. It’s a vertical group, as well.
Air Arms Falcon
About this time I was suspecting that the rifle does not like lightweight JSB domes. The next pellet up was the Air Arms Falcon, another lightweight domed pellet that’s also made by JSB. While Falcons are great in many air rifles, the first 5 landed in an open group measuring 1.658 inches, and I stopped right there. It looked like this pellet wasn’t for my TX, either.
What was happening?
Three out of 4 pellets I brought to the test were not good. Had I made a mistake with the Premier lites, as well? Was that good first group just a random event? I decided to shoot another one to see. This time, though, I laid the rifle the long way in the bag to see if there was any discernible difference.
Ten pellets went into a group measuring 1.241 inches this time. That is much closer to the first group than any of the other 3 pellets tried on this day, though it’s still larger. Maybe, laying the rifle lengthways made the difference? I don’t think so.
I decided to shoot another group with the rifle laid lengthways, again, just for comparison. This time I hit the jackpot and all 10 pellets went into 0.658-inches.
The TX 200 Mark III is capable of phenomenal accuracy at 50 yards, even when rested on a sandbag. From the limited testing I did I can’t say laying it crossways or lengthways is better. It works well both ways.
My rifle seems to shoot best with 7.9-grain Crosman Premier lite pellets. It does not seem to like any light pellets made by JSB.
This is not the end of our testing. Pyramyd Air has sent me a new TX200 Mark III that I promised you I would test right out of the box. Some of you have been concerned that my rifle is too well broken-in, and you think it may not reflect what you will get if you buy one. So, we shall see!
As a final note, I’d like to point out that I got several groups that were okay with the Premier lites and one group that’s exceptional. That’s the way it goes with any airgun — I don’t care which one you’re talking about. All the talk about half-inch groups at 50 yards has to be taken with this firmly in mind. You’re going to shoot larger groups most of the time.
That being said, Premier lites seem to be the most accurate and also the most forgiving pellet we’ve tested in my TX200. They may not always shoot into a super-tight group, but they’ll always shoot where you want them to. That’s what’s important.
by Tom Gaylord, a.k.a. B.B. Pelletier
Today, blog reader Paul Hudson shares his Theoben Crusader rifle with us. The Crusader is not as well-known in the U.S. as some other Theoben models, so this will be an interesting report.
If you’d like to write a guest post for this blog, please email us.
With its walnut stock, the Theoben Crusader is a large, handsome airgun.
The Theoben Crusader is a high-power breakbarrel airgun, identical in size and performance to the Beeman R1. Its stablemate, the Theoben Eliminator, seems to get far more press since it’s one of the most powerful breakbarrel airguns available. That power comes with a high price — a cocking effort of 50+ lbs. — that most shooters are not willing to endure for very long. The Crusader, on the other hand, is far easier to cock and is a more practical airgun. Based on the used guns I’ve seen for sale, either the Crusader sales are much lower or people tend to keep them. Few are seen on the usual airgun sales sites or at airgun shows.
The Crusader is a high-quality spring-piston rifle.
Measuring a full four feet in length and weighing 8 lbs., 3 oz. unscoped, the Crusader is a large airgun. Mine is .177 caliber; but .20, .22, and .25 calibers are also available. The Lothar Walther barrel is 16 inches long, and a muzzlebrake is standard equipment (.22-caliber Crusaders have an Anschütz barrel). There are no baffles in the muzzlebrake. No open sights are supplied by the factory, making an optical sight a necessity. My rifle has a right-hand walnut stock, but an ambidextrous stock can be had from the factory as a no-cost option. The pressed checkering does give enough grip to be functional. A very good non-slip recoil pad keeps the rifle in place. No plastic parts are used on the rifle.
The metal work on the Crusader is first-rate, with a high polish that’s typical of many British airguns, and the wood-to-metal fit is excellent. Allen-head screws are used throughout the gun except for one screw that secures the triggerguard.
Behind that screw, a Schrader valve allows the owner to change the air pressure in the gas spring. Note the thumb rest in the stock.
A gas spring
Like all Theoben springers, the Crusader uses a gas spring, not a metal spring. Cocking is butter-smooth and requires 38 lbs. of effort. The piston includes a sliding weight that reduces piston bounce and felt recoil. A Schrader valve at the rear of the receiver allows the pressure in the gas spring assembly to be adjusted to vary the power of the gun. Upon firing there’s no spring twang or vibration, just a quick snap. The sound level is moderate. And, due to the size of the gun and careful tuning, the felt recoil is mild for the power level.
The lower bolt is pinched between the breech block and the locking wedge to prevent vertical barrel movement. Note the taper at the rear of the barrel to make pellets easier to seat.
The barrel pivot setup on the Crusader is a little unusual. Most breakbarrels use a breechblock that’s close to the width of the forks of the receiver. Wide, thin shims may also be present between the breechblock and the receiver forks. The pivot bolt is then tensioned to the point that the lateral barrel movement is constrained. The breechblock on the Crusader has much more side clearance. Belleville washers are used to control the lateral movement. Belleville washers are cone-shaped from the side and are actually considered to be springs. A second bolt behind the pivot bolt mates with a hook on the back of the breechblock. The locking wedge pulls the breechblock tightly against this bolt to control the vertical movement of the barrel. Like many classic Webley rifles, the Crusader takes a bit of a slap to open the barrel for cocking.
The unusually wide breechblock/fork clearance is visible from below the action. (The photo is overexposed, leading to the yellow stock color. This was necessary to bring out the detail within the cocking slot.)
The Evolution trigger of the Crusader and other models has been criticized by some; and given the price of the gun, that may be justified. No creep is felt in the first stage, but the second stage is not as crisp as a Rekord trigger. As the gun came from the factory, the second stage breaks cleanly at 1 lb., 13 oz. The safety blade resides in front of the trigger and automatically sets when the gun is cocked. It can also be manually reset. Overall, I would rate the Crusader trigger as very good, just not quite as good as a Rekord or TX200 unit but not a reason to avoid the gun.
The trigger blade is almost straight; the automatic safety resides in the front of the triggerguard and is pressed forward to fire.
Velocities with the Crusader are similar to what’s found in a Beeman R1, and some lighter pellets in a .177-caliber rifle will go supersonic and ruin the accuracy. I tried a couple H&N Field Target Trophy Green pellets, but they traveled almost 1200 feet per second and missed the bullet trap at 25 yards. Extreme spreads with most pellets were under 20 feet per second, and a few varied by less than 10…very good for a springer.
These are the velocities the Crusader can deliver with the selected pellets.
Many pellets gave 5-shot groups around an inch in size at 25 yards. Several gave very good accuracy, including a few that surprised me. To get the best accuracy shooting from the bench, I had to hold the airgun loosely with my right hand and keep my left hand open. If I let my fingers touch the forearm, I had to make sure I didn’t squeeze the gun at all or the groups would open up. In other words, use the classic artillery hold. You cannot grip this airgun tightly and get good accuracy; it’ll take practice and proper technique to get the best results.
All groups were 5 shots at 25 yards, and the sights were not adjusted for the different pellets. It was interesting to see the difference in the points of impact. Predator Polymags and 8.4-grain JSB Exacts shot especially high in relation to the other pellets. Unfortunately, neither 7.9-grain Crosman Premier lites nor 10.5-grain Premiers heavies did much better than one-inch groups at 25 yards. While that’s not too bad, a number of pellets did far better.
Five H&N Baracuda Hunters made this 0.50-inch group.
Five Predator Polymag pellets made this 0.40-inch group. Good enough for hunting.
Gamo TS-10 surprised me with a 0.45-inch group; but their size seemed a bit inconsistent, and there were some flyers with this pellet.
Skenco Big Boys gave this nice 0.43-inch group. The group is almost twice as wide as tall.
The 13.4-grain JSB Monster also produced a 0.43-inch group.
The Crusader really liked the 8.4-grain JSB Exacts, as this round 0.24-inch group shows.
Best accuracy came from the Beeman Kodiak pellet. This group above is just 0.23 inches.
Adding it all up
Why buy a Crusader? After all, it costs just over $1000, and that price will keep many away. Compared to a Beeman R1, the size and power are identical. The R1 has a better trigger, but the Crusader has a better firing behavior due to the gas spring. The Crusader also has a far nicer stock, better metal finish and includes a factory muzzlebrake. Between my Crusader and my R1, the Crusader shoots more pellets accurately and will shoot slightly smaller groups, probably due to the fine Lothar Walther barrel. Unfortunately, the Crusader is more hold sensitive than my R1.
Both rifles should last a lifetime with proper care. It’s possible to upgrade an R1 with a new stock, a gas spring, muzzlebrake, etc., but you’ll end up spending more than the cost of the Crusader and still do not have the nice metal work. If you can afford it, the Crusader offers very good accuracy in a nicely finished package.
Theoben Production ceases
In October, 2012, Theoben Ltd. in England announced that they were entering liquidation (bankruptcy). It remains to be seen whether another company will take over production rights for Theoben springers.
by Tom Gaylord, a.k.a. B.B. Pelletier
Photos and report by Earl “Mac” McDonald
This is the final report about Mac’s vintage steel-breech IZH 61. We are only doing two reports — partly because the rifle performs just like the one that’s being sold today, but mostly because Mac sold this rifle at the Roanoke airgun show this past weekend. He also bought one just like it that was like new in the box because he got a super price at the same show. That one will be given to some fortunate youngster, as part of Mac’s “Arm the Children” program!
As I reported in Part 1, this vintage rifle has a truly adjustable two-stage trigger, instead of just being able to reposition the trigger blade like on the current gun. Mac had it set to release at 27 oz., and he says it was crisp.
Someone wanted me to post a photo of the entire vintage rifle, but there isn’t that much difference between it and the current one. I didn’t think it was worth showing. Yes, if you’re a fanatic collector, there are some small differences; but I spent the weekend with the vintage gun before it sold, and it’s pretty much the same as what they sell now except for having a steel breech and metal clips.
On the subject of the metal clips, Mac says he has had some plastic clips that got worn to the point that they would no longer stay in the gun as they should. They’re supposed to advance one pellet each time the sidelever is pulled out to cock the rifle, but he said some of his would shoot out the side of the rifle because they’re under spring tension.
I showed the sights on this rifle in Part 1, but Mac tried both the peep sight that comes with the rifle and also a Tasco Pro Point dot sight with a 4 MOA dot. At the 10 meter distance he shot, the dot covered about 0.35 inches He e got equal accuracy with both types of sights, but all the groups seen in this report were shot with the Tasco.
He rested the forearm of the rifle on the palm of his hand and shot off a bag rest at 10 meters. We wanted to keep the results equivalent with those I recently got with the new rifle. And he also shot at 10-meter rifle targets, which is why he elected to use the dot sight. The hole in the factory peep sight is so large that there’s a loss of precision when using the smaller 10-meter rifle bulls. They get lost in the hole (meaning you can’t tell when they’re exactly centered). He could have used pistol targets that have a much larger bull, but he wanted his test to look just like mine.
Mac shot 5-shots groups instead of 10-shot groups. Things got confused in our talks, so we didn’t shoot the same number of shots per target. Still, I think you will see some interesting things as we go.
JSB 8.4-grain Exacts
The first pellet tested was the JSB Exact that weighs 8.4 grains. Five shots at 10 meters produced a group measuring 0.95 inches between centers. That’s pretty big for just 10 meters!
There are some indications of tumbling with the JSB, so it’s possible the rifle wasn’t stabilizing it. That would account for the large group.
Next he tried RWS Hobby pellets. These are often among the most accurate in a low-powered rifle, but not this time. Five Hobbys made a 0.90-inch group.
H&N Finale Match
Next up were H&N Finale Match Pistol pellets. Five of them made a group that measured 0.80-inches, but notice that one is apart from the other four. If there was something wrong with that pellet, it could explain why it’s apart. This might be the right pellet for the rifle, and it’s a good example of why one 10-shot group tells you more about accuracy potential than three 5-shot groups.
The next pellet Mac tried was one you can’t buy anymore. The Eley Wasp has left the stage, at least in the version Mac was shooting. It was an oversized pellet that sometimes cured accuracy problems for rifles with larger bores. In this rifle, 5 shots made a group that measures 0.70 inches. You’ll also notice that there don’t seem to be any signs of tumbling like there were with the JSBs.
Five Eley Wasp domes made a group measuring 0.70-inches. This group also has a single stray pellet, which means it might also have more potential than seen here.
RWS R10 Pistol pellet
The last pellet Mac shot was the RWS R10 Pistol pellet. These grouped best, with 5 of them making a 0.50-inch group. While that looks good in comparison with the other groups, it doesn’t begin to equal the groups I got with the new IZH 61 shooting 10 shot groups! That means is we have to revise our thinking about the old steel-breech/metal clip guns, don’t you think?
Mac and I discussed these results at length, and we believe that the steel breech IZH 60/61 has perhaps become more accurate through the long lens of memory. Just as a walk to school was always 10 miles uphill in both directions when we were young, so it’s possible that these rifles were as variable back then as the new ones are now. From the results, we have to say that it looks like the current version of the gun is at least as accurate as the old one, if not more so.
We think that there were probably some very accurate rifles with steel breeches, and then the rest — which our test rifle seems to be — were only good plinkers. I know this test was hardly exhaustive, nor was it entirely without bias. Even so, I think we must admit that the new rifle beat the old one in this case.
What do you think?
by Tom Gaylord, a.k.a. B.B. Pelletier
Today, I’ll apply what I learned about bending an airgun barrel to a real problem. As I said in several earlier posts, I have a BSF S70 breakbarrel that came to me with a peep sight installed but no open sights. BSF rifles aren’t common in the U.S., so finding a correct rear sight would take some time; but more importantly, I like the peep sight that’s on the gun. It was one that Air Rifle Headquarters sold as an optional sight, but the owner of this rifle removed the original sights and didn’t replace them when he sold the gun. So, all I have is the peep.
When I tried to sight in the rifle, I discovered that it was shooting 2-3/4-inches high at 10 meters, which would put it even higher at 25 yards. Either the front sight had to be raised (because the peep was adjusted as low as it will go), or the barrel had to be bent. Since the front sight is dovetailed into the barrel, I decided to bend the barrel. That was two years ago. Since then I’ve been researching ways to bend barrels and thinking about the equipment needed to do the job.
This report has already documented the simple fixture I constructed, and you can read how it worked in the earlier parts. Now, I’m going to bend the barrel of this pristine collectible air rifle so I can shoot it and hit what I’m aiming at.
The barrel-bending fixture is quite simple to set up. It uses a c-clamp to apply steady pressure on the barrel and a ratchet wrench turns the clamp slowly, so the bend is under complete control.
This was the final bend. This barrel is softer than the first one, but it springs back when the tension is released.
The S70 didn’t fit the fixture the same as the first rifle did. I had to make some adjustments, but there’s enough flexibility built in to allow that. As I started the bend, I noticed right away that this barrel was bending much easier than the other one had.
Remember what I said about metallurgy of the various airgun barrels? I said that you should treat each new barrel as though you were bending a barrel for the first time. That was good advice for this job, because the S70 required a lot less pressure to bend. So I went slow.
The beauty of this fixture is that you can take the rifle out and shoot it after each bend. So that’s what I did. Let me show you the first target, which explains how the work went. I shot the same JSB Exact 8.4-grain pellets as were used when the gun was first fired.
This target documents all the work that was done. It is explained in the text below. The group below the bull is the final 5 shots, 3 of which are in one hole under the number 5. The one at the lower left was fired before I was ready but didn’t bother me.
I knew the rifle was shooting high, and I had the former target that told me how high. So, I first bent the barrel a little then shot the rifle to see what had happened. The first shot after the first bend was still high, but the point of impact had dropped over a quarter-inch. That told me the S70 barrel was bending very easy.
I bent the barrel a second time and put another pellet in the same hole as the first. Then, I bent it once again (three bends so far), and the third shot was the same height but to the right of the first two. Obviously, I had to be more aggressive.
The fourth bend was more aggressive, and the shot that followed dropped into the black bullseye for the first time. Next, I bent the barrel more aggressively, again, and the shot dropped to almost the middle of the red center.
Bend six was even a little more aggressive, and the shot dropped a little more and went to the right. Bend seven was about the same as six, and that shot went into the same hole as shot six had.
Now I knew the barrel needed a lot more pressure to go as far as I wanted. So, bend eight was the most aggressive of all. It’s the one pictured in the photo above. The shot that followed was below the aim point for the first time, which was what I was after. Four more shots were in the same area, though one of them went off before I was ready and struck the target low and to the left. From this result, I knew I was done bending the barrel.
It was time to sight in the rifle with the adjustments on the Williams peep sight that was on the gun. This was the first time since that rifle first got the peep sight back in the 1970s that it’s been able to shoot to the point of aim at 10 meters!
The sight-in took a long time because the peep sight adjusts in very fine increments. But I managed to walk the pellets up the target until the final one was at the correct height. Now it was time to verify that the gun still shot well. I have the original target for comparison.
As you can see, the rifle shoots as well as before. All that’s been done is adjust the point of impact so the sights can be used at close range.
The Williams sight has a number of screws that are used to lock the sight in position, once it has been sighted in. They all have to be loose to adjust the sight; and when you tighten them at the end, they can make the POI move just a little. You have to check your work after you think the sight is locked down.
So, the fixture I made works for real-world applications, too. It doesn’t take up much space, and I’ll keep it around for any jobs that might arise in the future.
Bending an airgun barrel isn’t something to do lightly; but if you have to do it, it’s nice to know the job can be done with a minimum of tools and time. Today’s project took a total of 45 minutes, which includes bending, shooting and sighting-in the gun at the end of the job.