by Tom Gaylord, a.k.a. B.B. Pelletier
Today, we’ll look at the Disco Double out at 50 yards. I used the best pellets from the 25-yard test to speed up this test. No sense going over the same ground twice.
The first pellet I tried was the JSB Exact Jumbo RS. It did the best at 25 yards, plus it’s so light, at 13.43 grains, that it gives the rifle a little extra zing.
The rifle arrived at the range filled to 2,000 psi, so I went right to work. I clicked the scope up 5 clicks in elevation to account for the greater distance and began shooting. The day was surprisingly cold — about 28 degrees F. My trigger finger had very little feeling, yet I was able to feel when stage 2 engaged on the trigger every time. That’s important on this rifle because the trigger is very light on stage 2.
There was no wind on the range, which made this a perfect day for shooting a pellet rifle. The first 10 shots went into 1.558 inches between centers. That’s not as small as many 50-yard groups you’ve seen me shoot, but let’s keep testing.
Next up were .22-caliber Crosman Premiers. The first 3 shots went into 2.269-inches and I stopped shooting. These pellets weren’t going to work at 50 yards.
JSB Exact, 15.89 grains
Next up were the heavier 15.89-grain JSB Exact Jumbos that looked promising at 25 yards. They produced a 10-shot group that measured 1.778 inches between centers. It was a little larger than the JSB RS pellet group at 50 yards, just as it was a 25 yards. So far, no prize.
The last pellet I tried was the Beeman Kodiak, which just did fair at 25 yards. Here at 50 yards, they put 10 into 2.458 inches. That’s hardly accurate! I almost stopped shooting this group when I saw how the shots opened up; but I thought that after doing that with the Premiers, I ought to let one go the distance just to show you what it looked like.
Back to the JSB Exact RS
I wasn’t finished with the testing just yet. The rifle was topped off at 2,000 psi again, and I went back to the pellet that was giving me the best results — the JSB Exact RS. The next group of 10 was the tightest of the session, at 1.318 inches between centers. I’d adjusted the scope for the Kodiaks, so this one landed below the bull.
I then shot 2 more 10-shot groups with the RS pellet. The first measured 1.522 inches, and the second measured 1.543 inches. When I examined the target after bringing it back from downrange, I saw a pattern. The RS pellet wasn’t giving tight groups, but they were very consistent. Out of 4 groups, the total variance was 0.24 inches — from 1.3 to 1.5 and change. That’s pretty consistent.
What do we know?
We know this Disco Double can put 10 pellets into 0.365 inches at 25 yards. And with the same pellet, we know that it opens up to about 1.5 inches when the distance is doubled. We know it was warm when the 25-yard target was shot and cold when the 50-yard targets were shot.
And that’s about the only difference — other than I did remove the TKO silencer after shooting 25 yards. I think what I will do next is the following.
1. Clean the barrel.
2. Shoot 5 groups at 25 yards with the JSB Exact RS pellet.
3. Clean the barrel again.
4. Shoot another 5 targets at 50 yards.
One last feature I want to show you is the special optional barrel band Lloyd makes for the Disco Double. It has a Picatinny rail on the bottom, allowing you to attach a bipod at just the right spot with very little extra weight added to the gun.
When I originally tested the .22-caliber Benjamin Discovery rifle in 2007, it was a pre-production prototype that was made out of a Crosman 2260. I shot several approximately half-inch groups at 50 yards with Crosman Premier pellets, but they were 5-shot groups. Now, I’m shooting 10-shots groups that I know are going to be larger. I didn’t use the JSB Exact RS pellet because it didn’t exist back then.
I believe this lightweight Disco Double has more accuracy than we’ve seen to this point. I think it must be capable of shooting at least one 1-inch group out of 5 at 50 yards. So, the test continues.
by Tom Gaylord, a.k.a. B.B. Pelletier
Today, we’ll look at the accuracy of the Disco Double. Before that, however, I mounted a scope, a TKO airgun silencer that they call a muzzlebrake or a lead dust collector, and something I’ve never seen in print before but something I’ve used on many precharged air rifles over the years — a bolt keeper!
What’s a bolt keeper?
First, let me tell you that when I mounted the TKO silencer, it fit the barrel perfectly. There were no barrel alignment issues that I was warned about, and I checked closely. This unit is very well made and looks beautiful on the gun. The unit I’m testing is 8-1/4 inches long; and, yes, Lloyd, I checked that it indeed is a .22 caliber before mounting it. However, when the silencer is on, the top end cap does not fit.
When I shot the gun with it on the first time, I have to say I was underwhelmed. It was quite loud. A second shot confirmed this. Then, I held the rifle to my shoulder and fired a third shot. That’s when it hit me — a blast of air in the face not unlike the glaucoma test eye doctors do. The bolt was opening and discharging compressed air with each shot!
This happens a lot with precharged guns and it doesn’t matter how cheap or expensive they are. The bolt handle lifts up and air comes back through the action. On the lightweight Disco Double, it only begins to happen when the rifle is at the bottom of the power curve, which is where it was when I tested it this time.
A simple fix is to fasten a rubber band around the bolt handle to hold it closed during the shot — a bolt keeper. Once on the gun, I just leave it there. Even though it’s not needed until the end of the power curve on this rifle, I don’t want to worry about it. You can cock and load the rifle with the band in place.
With the handle held closed in this fashion, the rifle suddenly became very quiet — as in Benjamin Marauder quiet! I now understand why shooters have been so excited about this unit. It really works!
NOTE: Due to several reader questions about this silencer, I am removing it from the rifle and returning it to Lloyd. Silencers are a very touchy subject, since owning one that will function on a firearm requires a license for each specific silencer. I don’t want to mislead any reader, so in the interest of clarity I am simply not going to use or possess this item any longer. I wrote an article on silencers that can be accessed here. If you have any questions on the subject, I recommend you read that article.
The rifle now weighs 6 lbs., 11 oz. with everything installed. That’s very light for a serious air rifle.
I mounted a UTG True Hunter 3-9X40 scope on the rifle. Since UTG packs rings with this scope, I used them, but they’re Weaver-style mounts. So, I had to use a UTG Weaver to 11mm dovetail adapter to make them fit the dovetails on the rifle’s receiver.
I’ll be shooting from a rest at 25 yards today. The range is indoors, so wind is not an issue.
Sight-in was accomplished with .22-caliber Crosman Premiers; so after I was on the paper, I shot the first group of 10 shots at 25 yards. The hole they made is a little taller than it is wide, but it measures 0.569 inches between centers. While that’s okay for 25 yards, it isn’t great. I’d like to see something a couple tenths smaller.
Next up were Beeman Kodiak pellets. They’re identical to the .22-caliber H&N Baracuda pellets that Lloyd tested the rifle with, and they were what I had available. They put 10 into 0.655 inches between centers. Like the Premiers, that’s not bad…but not as good as I’d hoped.
Beeman Kodiaks opened up more, to 0.655 inches between centers. Only use them if you need a heavy pellet.
JSB Exact RS
I followed the Kodiaks with some JSB Exact Jumbo RS pellets. They’re even lighter than the Crosman Premiers, and sometimes they can be very accurate in precharged rifles. This was one of those times. Ten pellets went into 0.365 inches, which is exactly what I’d hoped for the Disco Double. This is the pellet for this rifle!
Nex, I tried the RWS Superdome pellet that’s always recommended. I don’t often have good luck with them, but a lot of shooters do. I stopped after just 4 shots, though, and you can tell from the lateral spread that measures 0.634 inches between centers that they weren’t going to perform.
JSB Exact Jumbo
The last pellet I tested was the JSB Exact Jumbo. These are usually among the top pellets in .22-caliber precharged air rifles, so I felt they deserved a chance. The first 2 shots were on a fresh 2,000 psi fill, and I’m not sure the rifle wasn’t overfilled by a slight amount because they both landed away from the main group. Shot 9, however, was shot while the rifle was grouping well, and I have no idea why it’s above the main group. The 10-shot group measures 0.647 inches between centers, making this the second-best pellet I tested in the rifle.
These 10 JSB Exact Jumbos measure 0.647 inches between centers. The first 2 shots are the holes at the right and bottom right of the main group. Then, the rest of the pellets went into the big group, except for shot 9 that went high. There is no explanation for that one. This is a pellet I would keep trying.
Filling from a hand pump
The biggest feature of the Benjamin Discovery, aside from the low price, is the fact that the maximum fill pressure is just 2,000 psi. It’s full right where other PCPs have run out of air. And that makes the Discovery extremely easy to fill with a hand pump.
Using the Discovery factory pump, I began the fill at just under 1,000 psi and pumped until the onboard pressure gauge read 2,000. It took exactly 100 pump strokes to fill the gun; and, until the final 20, they were as easy as inflating a bicycle tire. Only when the pressure passed 1,800 psi did I notice an increase in pump handle resistance.
One tip when filling with a hand pump is to go slow. Allow time at the top and bottom of each pump stroke for the air to flow through the various stages inside. If you don’t, you just waste energy and heat up the pump unnecessarily.
Observations so far
So far, I’m thrilled by the performance of the Lightweight Disco Double. The number of shots I get on a fill is large enough for serious shooting before it’s time for a refill and the rifle’s performance leaves nothing to be desired. A glance at the onboard gauge needle, and I know the status of the fill.
When I tested the original Benjamin Discovery rifles in both calibers, the guns I used were pre-production prototypes. I shot groups under 0.6 inches with both calibers; but at that time, I was shooting only 5-shot groups. The JSB Exact RS pellet did not exist at the time of that test. So, it’ll be interesting to see what this rifle can do at 50 yards with 10 shots. Remember — this is the first Benjamin Discovery production rifle I’ve ever shot!
by Tom Gaylord, a.k.a. B.B. Pelletier
My rifle is actually a BSA Super Meteor.
Today, you’ll see how I fixed the bad muzzle crown on the BSA Super Meteor, and then we’ll see if that had any effect on the rifle’s accuracy. You might want to read Part 7, again, just to remind yourself of what I faced.
The BSA project has been just that — a project from the start. All I wanted to do was test another vintage spring-piston air rifle for you and report the results, but this particular air rifle has challenged me at every turn. From the time I bought it at the Roanoke airgun show last September, it’s been nothing but a prolonged learning scenario. I won’t bore you by recapping all that’s happened; but if you want to find out, read Parts 1 through 7.
At the end of Part 7, I showed you a nasty muzzle crown, which I surmised was the reason that all the pellets were leaving the barrel with a yaw to their axis. They weren’t tumbling, because every one of them struck the target paper in exactly the same orientation. They were yawing, or traveling forward while pointing off to one side. Because the barrel is rifled, they were spinning on their long axis, but that axis didn’t happen to coincide with their flight path.
The BSA Meteor crown has some serious nicks in it. The dark spot at 10 o’clock is the deepest. Compressed air could escape through this channel before any other part of the pellet leaves the bore, and the jet of air could push the pellet over on its side.
The solution was to crown the bore; but as you can see in the picture, the Meteor’s muzzle is counterbored by more than an inch. In other words, it isn’t where it appears to be from the side. It’s deep inside the barrel, where the theory says it shouldn’t get damaged as easily. Only this one was — perhaps from over-zealous cleaning through the muzzle. Who knows? The point is that it had to be fixed.
My shooting buddy Otho suggested a piloted counterbore to face off the crown true and square to the axis of the bore. And he volunteered to make the pilot, so I slugged the bore for him and found it was a diameter of 0.176 inches. That seemed odd to him because it’s larger than the bore of a .17-caliber rimfire bullet that’s about 0.172-inches. But that’s the difference between .17 caliber and .177 caliber — which is important for airgunners and firearms shooters to know. The pilot he made measures 0.1745 inches and fits the Meteor’s muzzle comfortably.
Otho made the pilot for this counterbore.
The counterbore chucked up perfectly in my portable electric drill. I allowed extra length for the bore to go down into the barrel and touch the muzzle without the drill chuck touching the barrel.
The counterbore is chucked in the drill and set to run true. It sticks out far enough to cut the crown without the drill chuck touching the barrel.
Plugging the barrel
Before starting the work, I pushed 3 fat pellets into the breech and then pushed them with a cleaning rod to within 2 inches of the true muzzle. These will keep the metal chips from dropping down the bore.
I oiled the counterbore and pilot with a good grade of light machine oil before inserting it into the muzzle of the gun. The drill was set on a slow speed, but I can also control the speed by how hard I squeeze the trigger. I wanted a slow steady turn without putting much pressure on the drill. The counterbore is sharp enough to cut the soft barrel metal without a lot of encouragement.
The drill is set to run slow, and I’m also slowing it more with the trigger. You don’t need speed for a cut like this.
After about 10 seconds of cutting, I removed the counterbore and cleaned the new crown with a cotton swab. There was a band of bright metal around the muzzle where the counterbore had cut. Upon close examination, I could still see gouges in the bright band. The gouges were deeper than the first cut.
The new crown is bright after the first cut, but there are still gouges that need to come out.
I cleaned the counterbore with a swab and oiled it again. Then, I made a second cut on the crown. This time, I felt the drill pulse as the cutter removed the uneven metal. It became smooth, and I knew the cut was finished. When I cleaned and inspected the new crown this time, it appeared smooth and even. The job was done.
I apologize for the blurriness of this picture. Focusing on the crown is very difficult when I’m also trying to light it from the same axis as the lens is pointing. The lens is about one inch from the end of the barrel, and this was the best picture I got. There are still some faint marks on the crown. After examination with a loupe, I didn’t think they would be a problem.
At this point, I felt the crown was as clean as I could get it. And there was a simple way to see if this had made a difference. I drove the pellets in the bore out the muzzle and a few steel chips came with them. Next, I shot two RWS Hobby pellets offhand from 12 feet. If the crown was good, they would cut the paper perfectly instead of hitting sideways. And that’s what happened.
So, I backed up to 8 yards and shot 2 more shots from an improvised rest. These 2 pellets landed very close to each other and also showed no signs of tipping. I felt the job was done.
The two lower shots were from 12 feet. They confirmed the pellets were hitting the paper straight-on. The two upper shots were from an improvised rest at about 8 yards. They told me the crown is probably working.
Now for the test!
The test is a rerun of the Part 7 accuracy test. I used every pellet from the last accuracy test and shot at the same 10 meters.
Ten Eley Wasps went into 2.256 inches at 10 meters.
If you compare these targets to those in Part 7, one thing jumps out at you. None of these pellets tipped when they went through the paper. So, crowning seems to have solved that problem!
But the accuracy seems no better. The Hobbys did group better in this test, but the Falcons grouped worse. With groups this large at 10 meters, I’m not willing to say anything has improved. I’ve had cheap Chinese air rifles group better than this.
I have one trick left up my sleeve. I’ve noticed that the Meteor rear sight seems hinky and difficult to adjust, and I suspect it jumps around as I shoot. It’s not loose to the touch, but I don’t trust it to hold zero.
I’ll do one more test of this rifle with either a dot sight or with the See All Open Sight if I can get it mounted to the Meteor. If that doesn’t work, I’ll probably abandon this air rifle as a bad investment.
by Tom Gaylord, a.k.a. B.B. Pelletier
Okay, all joking aside — today, we’ll look at the performance of the Lightweight Double Disco that Lloyd Sikes built. Lloyd tested this exact rifle when it was still in its factory original condition, so we can compare that to the performance of the rifle after the conversion. I was pleased to see that my chronograph results and Lloyd’s are very close.
Before the conversion, the stock Benjamin Discovery accepted a fill to 2,000 psi. From that fill, the rifle got 21 shots of .22-caliber Crosman Premiers at an average 845 f.p.s., which works out to an average 22.7 foot-pounds. Lloyd did get more shots in his string, but he discounted all those that were not within 4 percent of the average velocity. That’s a subjective choice, but it’s what drives the numbers Lloyd is giving us for the factory rifle. The maximum velocity spread in this string of 21 shots was 40 f.p.s., with a low of 820 f.p.s. and a high of 860 f.p.s.
After the Lightweight Double Disco conversion, Lloyd shot the same Crosman Premier pellets on a similar 2,000 psi fill and got a string of 33 shots at an average 849 f.p.s., for a muzzle energy of 22.9 foot-pounds at the average velocity. Again, this number includes all shots that fell within 4 percent of the average velocity. The maximum variation in this string of 33 shots was 34 f.p.s., with a low of 831 f.p.s. and a high of 865 f.p.s.
The shot count made possible by the Lightweight Double Disco conversion went from 21 to 33 shots. The average velocity did increase by 4 f.p.s., but I wouldn’t concentrate on that because these numbers will change a little each time you record them. Essentially, the gun shot this pellet the same before and after the conversion — it simply got more shots after.
What did I get with Premiers?
I filled the rifle to about 2,100 psi because I wasn’t sure that my best pressure gauge agreed exactly with Lloyd’s gauge. I wanted to start in a slightly valve-locked posture and move up into the power curve as I went, and that’s exactly what happened. Here’s my shot string.
1-20 21-40 41-end
802 856 836**
822 856 832
817 852 828
826 852 825
831* 857 824
831- 855 820
833 857 816***
837 853 STOP (47 shots)
- Slowest shot in acceptable string
+Fastest shot in string
* First gauge photo
** Second gauge photo
*** Third gauge photo
If I accept the shots in this string starting at No. 5 and continuing through No. 41, I get 37 shots. They’ll have a maximum spread of 29 f.p.s., with a low of 831 f.p.s. and a high of 860 f.p.s. If I’m more critical and start with shot No. 8, which went 837 f.p.s., and still stop at shot 41, the total is 34 good shots, with a maximum spread of 24 f.p.s. The low in this string is 836 f.p.s. and the high is 860 f.p.s.
Do you see how this works? It’s entirely subjective. I’m deciding what to accept and what to reject. Once I start accepting shots, though, I keep on shooting until the last shot in my acceptable string has been fired. I can’t ignore any shots in that string because I won’t be able to chronograph my shots when I’m shooting in the real world, away from the chronograph.
You must pick the starting and ending points that you feel are best for what kind of shooting you want to do. That’s why a chronograph is so essential to the owner of a PCP. If I were to shoot this same string again with the exact same starting pressure, which is very difficult to control, I might get numbers that are similar but slightly different from these.
Next we will look at the performance with .22-caliber H&N Baracuda pellets. Lloyd tested the rifle with them, but I didn’t have any .22-caliber Baracudas on hand, so I substituted the Beeman Kodiak, which is the same pellet under a different name.
With the Discovery in factory trim on a 2,000 psi fill, Lloyd got a string of 22 shots that averaged 717 f.p.s. They produced an average muzzle energy of 24.2 foot-pounds (compared to the 22.7 foot-pounds produced with Premier pellets in the factory trim). Heavier pellets will almost always produce more energy in a precharged rifle. The maximum velocity spread with the Baracuda pellet in the factory Discovery was 29 f.p.s. The low was 697 f.p.s. and the high was 726 f.p.s.
The Lightweight Disco Double conversion running on the same 2,000 psi fill with Baracudas gave a string of 38 shots that averaged 713 f.p.s. The low was 699 f.p.s. and the high was 729 f.p.s., so the spread was 30 f.p.s. The average muzzle energy was 23.9 foot-pounds.
Baracudas got more shots per fill than Premiers
With Baracudas, Lloyd got 22 shots per fill in factory trim and 38 shots with the Lightweight Disco Double conversion. In both cases, the rifle gave more shots per fill with the Baracudas than with the Premiers. My thinking is that the heavier, slower pellet holds the valve open a bit longer and is able to go to lower pressure before it falls off the power curve.
What did I get with Beeman Kodiaks on a 2,000 psi fill (refer to the first photo of the pressure gauge to see where I actually stopped the fill)?
1-20 21-40 41-end
702 712 701
699- 720 693
707 716 695
714 718 696
709 714 683
719 726 STOP (45 shots)
- Slowest shot in string
+Fastest shot in string
While this string has fewer shots than the first one with the Premiers, there are actually more usable shots here because I learned where the needle on the gauge had to be in the first test. No air was wasted at the start of this string. I would accept everything from shot No. 1 through shot No. 41, giving me a total of 41 usable shots, with a spread of 29 f.p.s. The low was 699 f.p.s. and the high was 728 f.p.s.
I got more usable shots from Beeman Kodiaks than from Premiers, just like Lloyd did with H&N Baracudas. Our data seems to agree very closely. Lloyd’s low velocity was 699 f.p.s. and so was mine. Lloyd’s high was 729 f.p.s. and mine was 728 f.p.s. How is that for consistency? As I said, the H&N Baracuda and Beeman Kodiak are the same pellet.
Analysis thus far
The Lightweight Disco Double increases the useable shot string significantly, even though the rifle is no larger nor heavier than a factory Discovery. You can tell from a glance at the onboard pressure gauge if the rifle is still on the power curve, so there’s no need to count the shots.
All of what you have seen to this point was done with the stock Discovery striker spring (0.035″wire, 0.289″ OD, 1.99″ long , 16.5 coils) in place. But Lloyd also provided and tested a heavier striker spring (0.041″ wire, 0.300″ OD, 1.78″ long, 19 coils) that gives both the factory Discovery and the Lightweight Disco Double conversion more power.
To see what the heavier striker spring can do with Baracuda pellets in the Lightweight Disco Double, Lloyd recorded that the average velocity climbed from 713 f.p.s. to 764 f.p.s. That is an energy increase from 23.9 foot-pounds to 27.5 foot-pounds. The total number of shots dropped back from 38 to 25 shots. This shows how the Disco Double allows the power to be increased, and the total shot count to remain the same as the less powerful factory gun.
I haven’t reported on the trigger, yet. You may recall that I had Lloyd install an optional trigger from a Benjamin Marauder. Lloyd told me in a message that it’s set for a light first stage, and then an extremely light second-stage pull. I found at first that it was so light that I pulled straight through both stages without recognizing stage 2. But when I adapted to it, it’s really not as sensitive as a 10-meter target pistol trigger. Stage 1 takes 14.4 oz. of effort; and stage 2, while recognizable, does not increase the number on the electronic scale. It’s on the order of 10 grams or less.
So far, I’m delighted with the Lightweight Disco Double. If it turns out to be accurate, it could become my go-to PCP!
by Tom Gaylord, a.k.a. B.B. Pelletier
I’d planned to report on the velocity of the Lightweight Disco Double today and, as good fortune would have it, the new stock arrived yesterday! So, I installed it and took a photo for you to see. I think it looks fabulous!
This stock was made by Normand Morin who has a website at Discos R Us. The wood grain is a very striking brown tone that’s finished shiny. The inletting is perfect for my rifle, and it dropped in with a tight fit. I like it even better than the walnut stock the rifle was shipped with. If you want to dress up your Disco, take a look at what this man can do for you.
Isn’t it ironic that I reported on the $100 PCP yesterday, and today I’m looking at the Disco Double? That wasn’t planned; but since it worked out, I’m sure you’ll draw some comparisons from the contrast of the 2 rifles.
I saved these first shots just for you! This is the first time I have fired the rifle since it arrived. I figured Crosman Premier lites could do the honors since the rifle is basically a Benjamin Discovery. At this time, I have not yet installed the TKO muzzlebrake, so the sound is what you would hear from a factory Discovery.
The needle on the rifle’s built-in pressure gauge was reading just below the 2,000 psi mark, which is the edge of the green zone for air. There’s a separate green zone for CO2 on the gauge, but it doesn’t really do much because a CO2 fill never goes above the pressure of the gas at whatever temperature the gun is at when it’s filled. In other words, CO2 pressure isn’t determined by the fill — it’s determined by the ambient temperature.
Here’s the first string I fired:
690 739 736
709 748 —
707 757 —
718 750 715
726 757 729
720 745 724
732 744 714
728 742 716
735 753 713
729 742 701
723 754 STOP
After examining the shot string, I concluded that the reservoir pressure was slightly too high when I began shooting, so I filled it to a slightly lower pressure (on the rifle’s built-in gauge) and fired 5 more times. That gave me the following velocities:
At the end of these 5 shots the on-board gauge read 1,900 psi. That looks like the right pressure to me.
More Disco Double features
I told you in Part 1 that this rifle has too many features to cover in just a single report. Two more of them are the stainless steel male Foster quick-disconnect fitting that’s used as a fill nipple. Lloyd has machined it into the end cap of the lower reservoir tube and covers it with a black plastic cap.
There’s also a special barrel band he can provide that has a dovetail on the bottom for the attachment of a bipod. That looks particularly handy, and I’m thinking of doing just that.
Analysis of the velocity numbers
Now that I have a good first string on record, let’s see what it means. These numbers seem on the low side, though I did tell Lloyd that I wanted maximum shots over anything else.
Lloyd sent me several spreadsheets with his own test velocities that I’ll now compare to mine. Then, we can select a good performance curve for the rifle.
What did I do?
Dear readers, I just consulted the velocity spreadsheet Lloyd sent me and discovered that he was getting velocities in this rifle in the mid-800s, also using Crosman Premiers. But I saw right away what he was doing differently.
HE WAS USING .22-CALIBER PREMIERS, where I’d been shooting the much-harder-to-control .177 Premier lites. Apparently, this Disco Double is special. Not only does it get a lot of shots, it also shoots .177 pellets in the same barrel as .22 pellets!
I swear I’m telling the you the truth, just as it happened! When I made my “discovery,” I dropped a .177 Premier pellet down the muzzle of the gun and noticed it fell all the way down.
Yes, friends, B.B. Pelletier has done it once again. I’ll now give you 5 minutes to draw a crowd for my public humiliation.
I didn’t plan for this report to go this way, but I can’t write stuff this funny when I try. So, have a great weekend at my expense, and on Monday I’ll return with some different velocity numbers. These will be obtained with the .22-caliber Premiers that probably work much better in this gun.
by Tom Gaylord, a.k.a. B.B. Pelletier
You tell me that you enjoy the longer reports that pick apart certain guns and analyze them in great depth. You insist that I explain the technical terms and sometimes also the terms that are specific to shooting. We have a wide spectrum of reader experience in the shooting sports on this blog; so when I write about something, I have to keep that foremost in mind. I try not to jargonize or use insider language, although I’m sure that I do from time to time.
Today we begin what will undoubtedly become a huge report. I think you will enjoy it, but I am asking for your help in managing the questions and comments that will undoubtedly result. So, sit back and pour a fresh cup of coffee or tea, for I think this trip is going to be fun for all of us!
The detailed photos in today’s report are provided by Lloyd Sikes. My thanks to him for all his work.
The 2013 Roanoke airgun show was a poignant one for me. It was the first airgun show in more than a decade where my buddy Mac was not with me. He passed away on May 5, 2013, and I stopped going to events for several months afterward. Roanoke was my first outing since his passing.
I’ve already reported on the show and don’t need to go over that ground again, but one thing that happened there does need to be mentioned. While I was at my table, a man walked up with a Benjamin Discovery in his hand and told me he had bought it from me the previous year. I recognized the rifle as one Mac had sold (we were both at the same table), and I mentioned that to him. I could see in his eyes, however, that he was very concerned with the status of this gun right now!
He had shot the gun for about a year but really hadn’t used it that much. He said that it now had a slow leak that needed to be repaired and had brought it to the show to get his money back. I looked at the rifle and saw that it was in fine shape, and he had the hand pump that came with it but not the box. I fully intended to buy it back from him just because that’s what Mac would’ve done. So, we struck a deal, and the Discovery became mine.
It may surprise you to learn that I have never owned an actual Benjamin Discovery! When Crosman and I were developing the rifle in 2007, I tested two prototypes that were Discoveries in every way, but they were not production guns. They were Crosman 2260s that were converted to Discovery specifications. I’d helped develop the Discovery 6 years earlier, but I never actually owned one before now. And, I had a plan for this one!
At the same show, Lloyd Sikes, the owner of Airgun Lab, was set up on the other side of the room. For those of you who don’t know him, Lloyd is the man who invented the technology that became the Benjamin Rogue. But Lloyd is now taking Benjamin Discoveries and adding an additional air tube to double their air reservoir capacity. Mostly, he sells kits of parts to people who want to do the work themselves — it’s easy enough for most people. But he’s also building a few very special rifles from the ground up. For over a year, I’d wanted to test something Lloyd was building, and this Benjamin Discovery seemed the ideal subject!
I walked over to Lloyd’s table and had a chat with him. As fate would have it, he was working on something brand new. He had just started experimenting with what he calls a Disco Double with both reservoir tubes made from aluminum rather than steel. The result is a gun that is nearly as light as the original Benjamin Discovery! When I picked up the prototype gun he had on his table, I couldn’t believe it. It was so light! I wanted one just like it.
Lloyd and I had several conversations at the show, and I left my brand new Discovery with him to build a lightweight Disco Double. I learned that what Lloyd makes is not just one simple product. There are so many changes that can be made in the process of modifying the rifle that a lot of decisions have to be made. We made those decisions both at that airgun show and in emails as time passed. But the original idea of a lightweight Disco Double with dual aluminum tubes remained the core plan.
When I returned from the SHOT show last week and my mail was delivered, there was a box from Lloyd! My lightweight Disco Double had arrived!
This report is going to be about the Disco Double that Lloyd built for me. If you want to know more about the basic Benjamin Discovery air rifle, read these reports.
The Benjamin Discovery is a basic precharged pneumatic air rifle that was built to sell at a very low price. The original concept was that the gun would come packaged with a high-pressure hand pump; and because the gun had a maximum fill pressure of 2000 psi, the hand pump would be very easy to operate. When I tested the preproduction guns in both .177 and .22 calibers, each was able to produce 10-shot groups smaller than 1 inch at 50 yards. At the Discovery’s low price, this was incredible performance.
Mac had purchased one of the original 4000 rifles that were made during the first year of production. These are unique because they have genuine walnut stocks that had been made for a special 2260 rifle that was never built. After the supply of these walnut stocks was exhausted, the company changed to beech wood, which is in keeping with the low cost of the gun.
The Disco Double lighweight
The rifle Lloyd built for me has two aluminum air reservoir tubes. In conventional Disco Double conversions, the kit contains either one chrome moly steel or one high-strength aluminum tube that gets added to the rifle’s existing steel tube for greater air capacity, but Lloyd made my rifle with dual aluminum tubes — the first of its type! The No. 1 purpose of this design is weight reduction, and secondarily it increases the air capacity for more shots.
The original base rifle in factory trim weighed 5 lbs., 7 oz. The original air capacity was 130cc. The rifle as now modified weighs 5 lbs., 8 oz. and has an air capacity of 199cc. That’s 53 percent more air. The air capacity has not doubled because the aluminum tube wall thickness is greater (than steel) to provide the necessary strength. So, the tradeoff with this conversion is lighter weight (than an all-steel conversion) for a little less total air, though the air capacity is still boosted greatly.
This is the completed lightweight Disco Double, minus the stock. The tubes have been finished in black to match the barrel. The original Discovery trigger is still attached to this rifle, but will be exchanged for a Marauder trigger.
I want to point out that Lloyd is building his guns with a safety reserve of well over 4 to 1. In other words, the guns are rated for well above 4 times the air pressure at which they’re working. Well above!
A normal Disco Double will have a Discovery trigger. Perhaps you’ve read about this trigger in your research on the internet. It’s functional, but it’s certainly not a fine trigger. I can use it without any problems; but if I had my choice, I’d like something better. Well, this time, I did have a choice; so I had Lloyd install a Marauder trigger on the rifle he made. He then had to find a triggerguard because the guard on the Discovery would not have worked.
Lloyd did an enormous amount of testing of my gun since it was the first of its kind to be built. And he has supplied me with the test data, so I have at my fingertips a whole library of velocities, pellets, fill pressures and some other things I will mention in a moment. If only all the guns I reported on had this kind of data at the start! But Lloyd is a very careful engineer, and I’ve come to know that he documents his work quite well.
Where did Lloyd get the idea for the Disco Double? Is the Benjamin Discovery somehow deficient in air capacity? Not really. But Lloyd was building a special .25-caliber conversion of the rifle for a customer, and it ran out of air very fast. The double air tubes were put there to make that big .25 a workable solution. And, after seeing what those tubes added to the rifle, Lloyd naturally expanded his conversions to the basic rifle, and the Disco Double was born!
The main goals of Lloyd’s kit are:
1. Safely add additional air capacity for more shots.
2. Restore the shot count after making power increases.
3. Maintain the light weight of the Discovery.
4. Provide a kit that can be installed by any airgunner who routinely works on his own airguns.
Lloyd and I agreed that it would be best to be able to preserve the original rifle, so if I ever wanted to put it back the way it came, I could. So, the factory walnut stock wasn’t touched. To fit the new double tubes, that stock would have to be routed out. Instead, the factory stock was returned to me as it came, and Lloyd is having a new beech stock made for me by his friend Norm. When that stock arrives, I’ll mount it and return the walnut stock to Norm, who has loaned it to me for photos and to get started with my testing.
Lloyd also produced an upgraded striker spring to give the new rifle more power. Of course, it does reduce the total number of shots; but since the air capacity has been expanded, you don’t notice the reduction over the factory rifle. Lloyd has also provided me with the test data for this performance part.
A kit of parts to make your Discovery into a Disco Double costs $165 as of the date of this publication. What you see here will cost $250 in a kit of parts. The aluminum tubes are much more expensive, and I also don’t believe the Marauder trigger has been included in that price.
This first report has been a long one, and we’ve only just begun to see this rifle. The next report will also have a lot more of the background development information, along with some velocity testing.
Oh, I guess I should tell you that this is a .22! And you can forget the serial number because this one stays with me.
by Tom Gaylord, a.k.a. B.B. Pelletier
My rifle is actually a BSA Super Meteor.
I’m headed to Las Vegas this weekend for the 2014 SHOT Show, so I’m asking veteran readers to help the newer readers more than usual. And I thank you in advance.
Tuesday’s blog will have something very important. It’s the first day of the SHOT Show, and I’ll show you something brand-new. It’s a pretty big deal, so it’s worth a look. Now, let’s get to today’s report.
Today, we’ll look at the accuracy of the BSA Super Meteor Mark IV that I’ve been working to restore. This report was never supposed to be an ongoing saga. It was supposed to be a quick 3-part look at a vintage air rifle, but the Meteor that I bought at the Roanoke airgun show last September turned out to need almost one of everything. So, I hunkered down and went to work.
I said in one of the earlier parts that fixing up an old spring-piston rifle is a lot like rebuilding an old tractor. Man, was that ever a prophesy! I had no idea that I would have to get down into the guts of the rifle to get it shooting again; but if you’ve followed along on all the earlier parts, you know that’s exactly what happened. Now that the old girl is shooting like she should, let’s see how accurate she is.
This is a vintage spring rifle with open sights, so I like to begin shooting those at 10 meters. Since I have no idea how accurate or inaccurate they are, it’s best to start close. If the groups show some promise, I can always back up to 25 yards and shoot a second test.
I figured a vintage airgun deserves a vintage pellet, so I broke out some obsolete Eley Wasps in .177 caliber as the first pellet. The first 2 shots were to sight in, and shot #1 was low, so I tried to adjust the rear sight up using the adjustment wheel. Alas — it didn’t move the sight! The backup plan was to loosen the rear sight blade and slide it higher. I also noted that the whole rear sight unit needed to be snugged down, so that was also done.
These .177 Eley Wasps are from the same timeframe as the Meteor rifle.
Loosen the 2 screws and slide the sight blade up to raise the point of impact.
Before we proceed, a word about .177 Eley Wasps is in order. Many of you know that the 5.56mm (.22-caliber) Eley Wasp is a particularly fat .22-caliber pellet. It’s often the best in vintage airguns whose bores are on the large side. But the .177-caliber Wasp is not an oversized pellet — at least not the ones I have. I often choose these pellets for guns with larger bores such as the Meteor, forgetting that these aren’t the best or biggest .177 pellets around.
I shot only 8 pellets at the target because the group grew to 3.559 inches between centers, and it didn’t seem worth my time to finish. But that wasn’t all I noticed. Most of the pellet holes are ripped out to the right, as if the pellets were not traveling straight. We know from the previous velocity test that this rifle now shoots fast enough to not tear target paper when the pellets pass through, so this tearing had to have been caused by the pellet’s orientation and not its velocity.
It only took 8 Eley Wasp pellets to convince me that this was not the right pellet for the Meteor. Notice the tearing of the paper! It’s all in the same direction. I’m cutting off parts of the bulls in this photo because they contain another group from another pellet.
Crosman Premier lite
These results were enough to convince me to use modern pellets in the Meteor. The next pellet I tested was the Crosman Premier lite. This time, I fired all 10 pellets, and the group was much smaller than before, but it still measured 1.73 inches between centers. That’s horrible for any air rifle at 10 meters!
What was even more surprising is the fact that the Premiers also tore paper to the right of the main pellet hole. In fact, they tore in exactly the same place!
It looks like 9 holes, but there are 10 Crosman Premier lite pellets in this group. It measures 1.73 inches between centers…and notice the tearing of the target paper in exactly the same way that the Eley Wasp pellets tore it.
If the pellets were tumbling in flight, the tears would be randomly scattered around the main hole because the tumbling pellet would change its orientation all the time. But because they are all in the same place, it looks like the pellets are tipping as they exit the muzzle and flying straight to the target in that tipped orientation. Hmmm! Have to think about that.
Air Arms Falcon
The next pellet I tried was the Falcon from Air Arms. I selected this pellet because the heads were sized large, at 4.52mm. They have the largest heads of any .177 pellets I have.
They put what looks like 9 shots into 1.863 inches between centers. Once again, several of the holes are torn on the right side.
The final pellet I tested was the RWS Hobby. This is a large wadcutter that sometimes is very accurate at 10 meters. But not this time. Ten went into a group that measures 2.05 inches between centers. They also tore the paper to the right of the main pellet holes.
I knew something was wrong with the rifle because these pellets all fly at different speeds. There’s no way a tumbling pellet can tear the paper in exactly the same place when they all get there at different times. For even one single type of pellet to do that is hard to believe, but for 4 different types…it’s impossible. The pellets have to be leaving the muzzle tipped on their edge and remain in that orientation all the way to the target.
I know that most of you have guessed what’s wrong with the rifle by this point, but I hadn’t. Of course, I didn’t have someone pushing my nose into the facts like you have in this report. It wasn’t until my buddy Otho came by for a visit. I showed him the targets (because he has an interest in the Meteor, as you recall), and he said, “I’ll bet that barrel needs to be recrowned.”
Oh, my gosh! How could I fail to see that? Of course that was the problem. When I brought out the Meteor for him to look at, he saw it right away. I bet you will, too. The muzzle is backbored by more than an inch; but with a tactical flashlight, we were able to look down inside.
See the dark spot at 10 o’clock? It appears to be a nick in the muzzle. How it got there I don’t know, but it should be fixed.
The saga continues!
Yep, this Meteor is like an old tractor, all right. Just when you think you have the thing running and looking spiffy — the magneto quits. These days, there’s only one old man in Kansas who can repair them. Actually, I protesteth too much because I really enjoy working on this gun. It wasn’t made in China, yet it has turned out to be even worse than most of the very poor-quality Chinese airguns I’ve tested in the past.
In truth, there’s a lot of great engineering in this rifle, as well as a ton of abuse. You BSA Meteor owners out there know that I’m not purposely beating up your favorite airgun. It’s just that it challenges me at every turn. But that’s a large part of what makes this hobby interesting. After all is said and done, I’m not upset.
OK, take that report on a Friday and run with it! Remember, I’m on my way to Las Vegas and cannot answer as many comments as normal.