Posts Tagged ‘breakbarrel’
by B.B. Pelletier
Let’s look at the power and velocity of the Gamo Rocket IGT .177 breakbarrel air rifle. You learned in Part 1 that the numbers printed on the box and gun were in disagreement with the Gamo USA website and Pyramyd Air’s site, but it turns out that 1,300 fps is the correct velocity according to an email Edith received from Gamo’s vice president of sales. Well, Edith spotted yet a third velocity claim — this time on the end flap of the box. A sticker listed the velocity as 1,000 f.p.s., with no further explanation. We’ll clear all of this up and find out just how fast this rifle really does shoot.
I remarked in Part 1 that the cocking effort of the rifle seemed low for a gas spring, which is what IGT (Inert Gas Technology) means. My guess was the rifle cocked at between 30 and 35 lbs. of effort, which is a good 10 pounds less than other gas springs that generate similar power. My bathroom scale confirmed that the test rifle cocks with just 33 lbs. of force, making it easier than most gas springs. The piston stroke is quite long, which is how they manage to generate all that power from such an easy-cocking powerplant. I applaud Gamo for using the physics of the gas spring in this creative way.
I also remarked that the new Gamo Smooth Action Trigger or SAT, as they call it, is a large leap forward from any Gamo trigger I have ever tested. It’s adjustable via a hard-to-access Phillips screw located behind the trigger blade; and when I attempted to adjust it, I discovered that it was set by the factory to the best position.
Screwing the adjustment screw clockwise reduces the stage-two pull length and counterclockwise does the reverse. The screw was in as far as it would go, but I did unscrew it a full turn and verified that it does increase the second-stage pull length.
The trigger released at 4 lbs., 4 oz. with good consistency. The first stage is very light (just one ounce) and stops positively at stage two. This is the kind of sporting trigger that will please many shooters, and I’m so glad to be testing it.
The last comment on the trigger is that Gamo has made the safety entirely manual. The blade is in an usual (for Gamo) place, but it doesn’t go on when the rifle is cocked. I see that as a positive step toward customer satisfaction. Gamo has somebody who knows how to design airgun triggers.
And now to the principal business of the day. I tested the Rocket IGT with four pellets — two made of lead and two that are lead-free. The first pellet tested was the JSB Exact 10.34-grain dome — a heavy pellet for a .177. With a gas spring, there’s no coiled steel mainspring to worry about, so the question of whether this heavy pellet is suited to a spring-piston powerplant is moot.
The JSB Exact pellet got an average velocity of 822 f.p.s., which was below the estimate of 900 f.p.s. I made in Part 1. The velocity spread went from a low of 816 to a high of 828, so a 12 foot-second spread over 10 shots. That’s very consistent. At the average velocity and using weight of 10.34 grains, this pellet generates 15.52 foot-pounds of muzzle energy.
Next up was the H&N Baracuda Green — the new lead-free pellet that’s surprising us with its accuracy. And that’s why I tested it here — because I intend to try it out in the accuracy test, as well. They averaged 1100 f.p.s. on the nose, and the range went from a low of 1092 to a high of 1105 f.p.s. So the spread was a tight 13 f.p.s. At the average velocity, this 6.48-grain pellet averaged 17.41 foot-pounds. That’s good power for this rifle; and if these are accurate at 25 yards, they’ll be a good hunting pellet for rabbits, squirrels and similar game.
Following the Greens, I tried Gamo’s PBA Platinum pellet, a 4.7-grain lead-free dome that they pack with the rifle. This is the pellet they say will go 1,300 f.p.s. (although Gamo’s website still says 1,250 fps). In the test rifle, this pellet averaged 1,229 f.p.s., but the string was large. It ranged from a low of 1,214 f.p.s. to a high of 1,242 f.p.s. The spread was 28 f.p.s. While that’s not terrible, it’s noticeably greater than all other pellets that were tested. At the average velocity, this pellet generates 15.77 foot-pounds at the muzzle.
The rifle comes pretty close to the 1,250 f.p.s. claim still listed on Gamo’s site (as we write this) — but not the 1,300 fps they claim on the box and rifle.
The last pellet tested was the venerable RWS Hobby. This 7-grain lead pellet is often the fastest of its type. In the Rocket, they averaged 1,004 f.p.s. with a spread from 996 to 1,013 f.p.s. The spread was 17 f.p.s., and this pellet generated 15.67 foot-pounds of energy at the muzzle. Once again, the Gamo rifle met its advertised velocity with lead pellets.
Observations thus far
Gamo met the advertised velocity for lead pellets but was below the advertised velocity for their Platinum PBA pellets. Their Inert Gas Technology gas spring is easy to cock and doesn’t vibrate much when fired. And their new Smooth Action Trigger is performing just as nice on this rifle as the mockup in the Gamo booth did at the 2012 Shot Show.
I think you can sense my approval of this air rifle so far. It’s completely modern and nothing like the guns I usually favor, but it cocks easily, it generates the power it’s supposed to, is lightweight and has a fine sporting trigger. If it turns out to be accurate as well, I think Gamo has a fine new rifle in their lineup.
by B.B. Pelletier
Back when I reviewed the 2012 SHOT Show, I showed you several new innovations that Gamo was bringing to the market this year. This rifle, the Gamo Rocket IGT .177 breakbarrel, contains the first of those I will test. I’m testing rifle serial No. 04-1C-138639-11, for those who wish to keep track.
One of the new technologies is in the title of this air rifle. The IGT stands for Inert Gas Technology, which is Gamo’s term for a gas spring. The gas spring replaces the conventional coiled steel wire mainspring with several improvements. It’s lighter in weight, doesn’t vibrate as much when fired, is resistant to cold, and can remain cocked for long periods without suffering any degradation. Compressed gas doesn’t fatigue like steel spring stock.
The second technology in this new rifle is the Smooth Action Trigger, or SAT, as Gamo calls it. It’s a two-stage trigger that’s so much better than Gamo triggers of the past that it deserves its own blog. The aluminum blade is well-shaped and vertical; so when it’s pulled, it comes straight back and doesn’t rotate upwards into the stock. The two stages are very clearly separated and stage two is quite crisp. I will say a lot more about it in Part 2 when I test rifle’s velocity.
The two technologies that the Rocket IGT does not have are the Bull Whisper barrel — a polymer-jacketed barrel with internal baffles — and the Shock Wave Absorber (SWA) recoil pad that helps dampen recoil. Since the Rocket IGT is not a super magnum rifle, I guess it doesn’t need either of these. But Gamo advertises this rifle at 1,300 f.p.s. while shooting .177 non-lead PBA pellets, so it’s no slouch. That velocity is printed on the outside of the box as well as on the spring tube of the gun. On the Pyramyd Air website, the velocity is listed as 1,250 with PBA ammo…and that’s also what Gamo advertises on their website. Either way, that’s a lot of power. I would think we could see some of the heavier accurate lead pellets go out the muzzle in the 900 f.p.s. range, which would be ideal. [Note from Edith -- I'm checking with Gamo on this discrepancy, but I suspect it's 1300 fps.]
This is a lightweight, slim air rifle. It weighs just 6.1 lbs. due to the use of synthetics in the barreled action and a synthetic stock. It harkens to the days of the Shadow 1000 and, more recently, the Whisper. Unlike the Whisper, this rifle has no baffles at the muzzle. Even so, the discharge sound isn’t that loud. It’s a solid three on the PA sound scale, but it’s not objectionable.
I haven’t been able to keep my paws off the gun since taking it from the box, and I can tell you that the initial shooting impression is a good one. First of all, even though it has a gas spring, I’m estimating that the cocking effort doesn’t exceed 35 lbs., and I wouldn’t be surprised to see it closer to 30. A gas spring exerts full pressure from the moment it’s first compressed, so you notice the cocking effort a lot more than with a coiled steel spring — but this Gamo is very nice in this respect.
The piston stroke is extra-long, which is where the power comes from. When you break the barrel to cock the gun, it folds down to within just four inches of the triggerguard. That means the cocking link is going far to the rear, pushing the piston into lockup with the sear; and that, in turn, means a long piston stroke.
The trigger is two-stage and very crisp. Old-timers will not recognize it as a Gamo trigger. It’s also adjustable, and I plan to evaluate it in Part 2.
The gun fires without a lot of recoil or vibration. It seems to have a lot of power, but we’ll find out for sure in Part 2. One thing I definitely love is the non-automatic safety. It’s there for you to apply — or not — as you choose, but you’re not forced to take it off before every shot. Bravo for Gamo!
More impressions of the rifle
The stock is slim and fits me quite well. It’s entirely ambidextrous, with a raised cheekpiece on both sides of the Monte-Carlo profiled butt. The pistol grip has a slight swell on both sides. Nothing about the rifle favors a right-handed shooter over a southpaw, which is a big plus in its favor.
The synthetic material the stock is made from is cool and slightly rough to the touch. The butt sounds solid, which I know will be appreciated by most shooters. The pistol grip and forearm are both slightly roughened where the hands want to grip.
The barrel is a thin steel tube surrounded by a fluted synthetic jacket. That’s become a Gamo trademark in recent years. Though I don’t care for the aesthetic, it does keep the weight off.
Surprise at the muzzle!
I casually glanced at the muzzle to examine the crown and was surprised to see no rifling inside the barrel at that point! Using a magnifying hood and a tactical flashlight I can see that the rifling ends considerably before the end of the barrel, like almost an inch deep. So, there really isn’t a crown to this barrel, just what could be called a counterbore at the muzzle. Unlike a true counterbore, the rifling just ends without a step in the barrel. The pellet is free to fly on its own at this point. What it will or won’t do for accuracy remains to be seen, but I’m intrigued!
There are no open sights, nor are there provisions for them. This rifle is meant to be scoped and comes with a Gamo 4×32 scope in rings that are ready to mount. The base clamps to 11mm dovetail grooves cut into the spring tube, and a single vertical scope stop hole is provided. The rings mount with a Torx wrench that’s provided, and both the base screws and cap screws use the same wrench, which is a big plus. The caps have two screws apiece. I had the scope on, leveled and adjusted for my eye relief in less than 10 minutes.
Gamo has been advancing their air rifle technology greatly over the past decade. This year they’ve hit the afterburners! This new rifle looks right, feels right and has a great trigger. Let’s hope it’s also accurate. If so, the Rocket IGT could be a home run for Gamo.
by B.B. Pelletier
El Gamo 68 is a futuristic breakbarrel from the past.
Today, I’ll take the El Gamo 68 to the next level of accuracy testing. I mounted a scope and went back to 25 yards to see what this gun can do.
Blog reader Mike sent me a trigger shoe he wasn’t using, and I installed it on the rifle’s thin blade. It made all the difference in the world. I don’t think I could have endured the 80+ shots that went into today’s test without it! Thanks, Mike!
The trigger shoe made the heavy pull pleasant.
I mentioned mounting a scope on the rifle before I checked it out. The 11mm scope dovetails are cut into the top of the spring tube and are very short by today’s standards. I was able to mount only a Leapers Bug Buster scope using 2-piece BKL mounts. The Bug Buster is a very compact scope, whose size compliments the 68 — and the eye relief worked out fine, so this was a happy coincidence.
I used this test not only to see how accurate the 68 is at 25 yards, but also to see if there’s a difference between seating pellets flush and seating them deep with an Air Venturi Pellet Pen’s PellSet. Each pellet shot one 10-shot group seated each way. Let’s see how it went.
H&N Finale Match Pistol pellets
I first shot a 10-shot group of H&N Finale Match Pistol pellets seated flush with the breech. The group measured 0.963 inches between centers.
Then, I shot another 10-shot group with the same pellets seated deep. It measured 1.232 inches between centers. Clearly, the flush-seated pellets were best.
Air Arms Falcon
Next, I tried the Air Arms Falcon dome. Ten pellets seated flush gave a group measuring 1.163 inches between centers. Ten seated deep printed into 1.28 inches. This is too close to call.
The last pellet I tested was the RWS Hobby pellet. And here we had a reversal of the first test with the H&N target pellets –because the deep-seated pellets out-grouped the flush-seated ones. Flush-seated pellets grouped in 1.311 inches at 25 yards. Deep-seated pellets grouped in 0.888 inches, which was the best group of the test, though the initial sight-in group of Hobbys did group even better. But all the controls of the test weren’t in place when I shot that first group, so I can’t count it.
The results didn’t turn out as good as I expected. The 68 is accurate, but it’s not a 10-meter rifle in disguise. Having the trigger shoe makes the heavy trigger-pull comfortable, but a lighter pull would be much better.
As for the seating exercise, it seems to work with some pellets but not with others. And, of course, I haven’t yet experimented with different seating depths.
The next step with the 68 will be to disassemble the rifle and see what I can do to slick it up a bit.
by B.B. Pelletier
El Gamo 68 is a futuristic breakbarrel from the past.
As I said in Part 2, Mac and I simply couldn’t resist shooting the El Gamo 68 that I got from reader David Enoch at the Arkansas airgun show this year. And from the numerous reader responses, I see that we’re not alone in our admiration of this futuristic-looking breakbarrel from the past. Many owners have .22-caliber guns, which really surprises me, because I thought most European manufacturers, and especially El Gamo, produced mainly .177 airguns in the 1960s and ’70s, when this was new.
Unfortunately, I’ve been unable to locate a trigger shoe for the rifle. I probably got rid of one when I sold or traded a Webley Tempest years ago, though now I wish I still had it. If anyone sees an old Beeman trigger shoe for sale anywhere, please let me know, because this rifle really needs one.
It really didn’t begin as a test of this rifle. Mac was helping me test some new models you’ll be reading about later this month and asked if he could shoot the 68 when he finished with them. The test range was 10 meters indoors, and he produced a nice 5-shot group that can almost be covered by a dime in the center of the bullseye. It was so enticing that I decided to have a turn — which of course means a contest. Mac is a better rifle shot than I am, and we both know it. So when my 5-shot group came up noticeably smaller than his, he thought we should never speak of it again. And, Mac, after today…I probably won’t! I’ll add here that the next day he beat me by one point in a silhouette match at a friend’s place. That sounds close until you learn that my rifle was scoped and he was using peep sights!
But I digress. The fact is that we were shooting the 68 with the classic RWS Hobby pellet, and I have no idea how accurate the rifle really is. I just know that it shoots Hobbys well.
Well, Mac finally had to return home, leaving me with the 68 and much more to “test.” Much, much more, I hope!
Yesterday, I shot the rifle at 25 yards indoors and, once again, with Hobby pellets. Yes, I shot off a rest and used the artillery hold; but with this model, it’s a little more difficult to let the rifle float in your hands. The trigger has a stiff 8-lb. release, and the pistol grip forces the shooter to grip hard to squeeze that hard trigger blade. Other than that, the artillery hold was the usual one, but I mention the difference so you’ll know what went on.
The first shot went high and well-centered with the bull, so I settled in and fired 9 more just like it. The resulting group isn’t a thing of beauty, but it is what it is.
Last week I “discovered” that seating pellets with the new Air Venturi PellSet seemed to improve the accuracy of the Air Venturi Bronco I was testing. I took a lot of heat for mentioning that, because the test did not have the controls you usually see in this blog, but what the heck! I have a tough old hide, so go ahead and flog me!
I thought, why not try the PellSet with the 68 and really get the crowd in an uproar? I listened to several of you who advised me to start by seating the pellets as shallow as possible, so I adjusted the PellSet to do just that. Then, I shot a second 10-shot group at 25 yards and, lo and behold, it was smaller. I’ll probably never hear the end of this!
Now, to me, it looks like the intentionally seated pellets really do want to group better in this particular rifle. But what do I know? This was not a real test of seating pellets because there weren’t enough groups fired, plus there’s a lot more I want to test than just the single depth.
In fact, this wasn’t much of an accuracy test for the 68. Think of it as more of a “getting to know the rifle” session, because I plan to mount a scope and return with a genuine accuracy test in the next report.
But it sure was nice just to play with this little rifle once more! As a matter of fact, I think I’m going to find reasons to do more of this.