El Gamo 68/68-XP – A futuristic airgun from the past: Part 5

by B.B. Pelletier

Part 1
Part 2
Part 3
Part 4


El Gamo 68 is a futuristic breakbarrel from the past.

I’m sure many of you imagine that I’m immersed in airguns all the time, which is true. That my office is filled with all sorts of models (it is) and that my workshop bench is strewn with parts of projects in process. There’s just one problem with that view. I don’t have a workshop. When I really need a lot of room, such as for today’s report, I usually move to the kitchen, where I do my work on that time-honored bench — the kitchen table!

The other thing most readers don’t appreciate is how whipsawed I am with time. I can’t afford to spend a week or even two days on a project anymore. Back in the days of The Airgun Letter, I had one month to crank out the stories that are now written in about four days! If I spend more than three hours on a project before starting to write about it, I’m working on a 12-hour day because the writing and photography take so much more time than the actual testing. And so it was with some trepidation that I approached today’s report, which is a disassembly, evaluation, cleaning and lubrication of my Gamo 68 breakbarrel air rifle.

I wanted to do this because the 68 shoots very suddenly. It doesn’t vibrate like many spring guns, but the thump when it fires is very heavy — way out of proportion with the power of the gun. The trigger is very heavy, and I wanted to see what might be involved in bringing it down. It’s crisp enough, just too heavy for the release.

Because of the potential time element and the fact that I have no room for another disassembled airgun, I studied the rifle carefully for two months — the way a diamond cutter examines an important stone. And with all that study, I still did not recognize the way the gun is assembled. But one look at a schematic sent by David Enoch showed me what to do.

Only three screws have to be removed to take the action out of the stock. That’s no different than any other breakbarrel, but the location of the third screw is certainly different! It’s at the back of the spring tube.


This photo shows the action out of the stock. One extra screw was removed. The one below the triggerguard does not hold the action in the stock. It’s one of two screws that hold the trigger unit to the stock, and it doesn’t have to be removed to get the action out of the stock.

With the action out of the stock, you have access to disassemble the mechanism and do what I ended up doing to the rifle. The trigger is really a complex bullpup unit that’s entirely separate from the barreled action. By “bullpup,” I mean that the trigger blade does not directly contact the sear. It’s located many inches forward of the true sear and is connected by a long lever inside the trigger unit. If I want to improve the trigger-pull beyond what simple adjustment can do, I need to remove this unit from the stock to get access to the pins and levers.

I decided to leave that task for another day, as working on the powerplant was all I had time to do in this session.


You’re looking down into the aluminum stock that holds the spring tube. The trigger unit runs from almost all the way on top, where the trigger blade is located, to all the way on the bottom, where the true sear releases the piston. It’s a complex bullpup unit that must be removed as a unit for work. You can see the steel channel that holds all the trigger parts.

Because of the way the Gamo action is designed, I could set the trigger aside and go to work on the powerplant. The end cap is held in the spring tube by a single large pin that must be drifted out. The action was installed in a mainspring compressor for this next step.


Here you see the barreled action in the mainspring compressor with the large pin drifted out. The pin is on the table, next to the hammer handle. The spring tube is ready to come apart.

Moment of truth
Taking a spring-piston powerplant apart for the first time is always a surprise. You never know how much compression the mainspring is under, even when relaxed, and how far it will come out of the gun before it’s fully relaxed and the gun can be removed from the mainspring compressor. It was a real surprise this time, for the spring came out several inches before fully relaxing. If I had just drifted the pin and tried to hope I could hold the end cap with my body, I could have broken bones!


Like a python that swallowed a telephone pole, the mainspring just kept coming out of the spring tube until it was this far! As you can see, I didn’t have much more room on my adjustment screw.

Once tension is off the mainspring, the rifle can be removed from the compressor. The end cap, spring guide and mainspring can now be removed. The piston, though, is still held in the rifle by the cocking link. You must disconnect the link from the piston before it will slide out of the gun.

The 68 has an articulated cocking link, and I noticed a spot at the front of the cocking slot that was enlarged for the removal of the cocking link. That told me that I did not need to remove the barrel from the action to disconnect the link from the piston. Just line up the link end with the enlarged hole, and the end pops right out.


The cocking link is two pieces.


The end of the link can be removed from the spring tube through the enlarged hole at the end of the cocking slot. The two-piece cocking linkage helps you do this.

The mainspring and piston both told me this gun had probably never been apart before. The grease looked like factory grease, and there were many years of accumulated dirt and grime on all the parts.

The piston has a leather seal that looks brand new. It was a bit on the dry side. After I assembled the rifle, I lubricated it heavily. I’ll continue to do that many times over the next few months, until I’m satisfied that the leather is oily and supple once more.


Leather piston seal looks good.

The piston itself is a very strange duck. It has to be, because the trigger is autonomous from the powerplant. There’s a window on the side of the piston at the rear where the sear catches it when the gun is cocked.


Here you see the entire piston, which is a machined steel part. The rectangular window at the end of the piston skirt is where the sear catches and holds it when the gun is cocked. Only the piston seal and the machined section at the rear touch the inside of the spring tube, so that’s where the moly lubrication goes.

The inside of the spring tube was as dirty as the piston and mainspring. I put paper towels over the end of a long-bladed screwdriver, dipped the paper in alcohol, and cleaned the inside of the spring tube and compression chamber. This would also be the time to remove any burrs from the cocking slot, but there weren’t any on this one.

After the entire powerplant was cleaned, I examined that long mainspring. After all those years, I thought it had to be canted — and it was, though not as much as I’d imagined. Rolling it on a flat surface revealed a wobble at one end, which translated to a jolt during firing. Hopefully, I had a suitable replacement.

I found several possibilities, but the best one proved to be a replacement spring for a TX200, of all things. It’s a special spring Jim Maccari made some years ago and it has collapsed coils in the center and at one end. As you can see in the picture, it’s a lot shorter than the spring that was in the 68. The wire is thicker, but there are so many fewer coils that I knew it would fit. The fit inside the piston was about the same as the factory spring, and the fit on the spring guide was tighter. So, this is a good replacement.


Factory spring above, replacement below. The new spring will certainly be under less compression when the gun is not cocked!

I coated the new spring with a thin layer of black tar and inserted it back into the piston. The front and rear of the piston were then coated with a heavy layer of moly grease and installed back into the spring tube. The cocking link was inserted back into the enlarged hole, where it contacted the piston for cocking.

The spring guide was coated with moly and slid inside the mainspring as far as it would go. The end cap was placed over the end of the spring guide, and the barreled action was installed in the mainspring compressor, once again. This time, the amount the spring stuck out was drastically reduced.


The spring guide is steel. It was coated with moly and slid back inside the mainspring.


The new mainspring has just begun to compress. It’s a lot shorter than the old one!

The gun went together without a hitch! And that was when I noticed for the first time that the entire job from start to finish had taken me only one hour — including photos! That’s as fast as I could tune a TX200 (assuming I would, which would never happen), and it doesn’t require a mainspring compressor. This wasn’t the time-killer I thought it was going to be.

How does it shoot?
The rifle cocked with 22 lbs. of force before this tune. Now it takes 28 lbs. to cock it, and the final sear lockup takes a final crunch that wasn’t there before.

The gun fires with 70 percent less jolting than before, but its just as quick as it was before the tune. The feel of firing is atypical of a lower-powered breakbarrel, just as it used to be. I can now feel a little vibration in the powerplant that I think was previously masked by the heavy firing jolt.

I still don’t know the gun. It will take a session of velocity testing and shooting for accuracy before I can finish this report. Since I’ve already tested the gun extensively before, I’ll combine both of those things in the next report.

35 thoughts on “El Gamo 68/68-XP – A futuristic airgun from the past: Part 5

  1. Okay, you’re holding the trigger system for later but…

    In the photo of the lower receiver showing the trigger/sear linkage — are those adjustment screws at the bottom end (rather large too)… Access to them appears to require removing the sear from the lower…


    • Wulfraed,

      I showed the adjustment screws in an earlier post. The large screw you see here is the other one that holds the trigger unit in the stock/grip frame.

      B.B.


  2. Hello B.B. and Fellow Airgunners. Thank you so much for this report on the dis- assembly-assembly of El Gamo 68/68-xp. I’d forgotten about this particular model, so was very surprised when I saw it tonight. Let me explain how this particular blog ties into my dilemma. I have been itching to take my Weihrauch HW85 .177 apart almost as soon as I received it. I started out shooting 7.grain hobbies, and after the third shot, the pellet refused to exit the barrel. Having no knowledge of this blog back then, I phoned a trusted friend in Calgary, Alberta, my old teenage stomping grounds, and he suggested I put 2-3 drops of Crosman chamber oil in the piston chamber hole, as the piston seal sounded “dry ” to him. This cured my problem, however every once in a while, just when I think the problem is cured… thump. Nice little recoil, but the pellet stays where I placed it. After much deliberation, my best guess is the piston seal is too large for the tube. A bit of chamber oil loosens things up for a few hundred shots, and I achieve great accuracy too. Anyway, I have purchased a new piston seal, sooo , after reading this article, I think I just may take the plunge this weekend. It has just been procrastination on my part. So once again I thank you for a timely article. And so too sleep, per chance to dream of springs and seals and pins, etc., etc.
    Caio Titus


    • Titus,

      I doubt very much that your piston seal is too large. But is your rifle shooting at the Canadian-legal 500 f.p.s.? That could be the problem. The oil could be providing enough fuel to get it dieseling again, as most spring-piston guns do.

      B.B.



  3. Kitchens are always a great place to work. Good, flat table, bright overhead light, plenty of room to walk around the table, an oven for warming stuck parts, a freezer for shrinking parts that need to stay together with an interference fit. Reminds me of the time I needed to put new valve guides in a Honda motorcycle head. Procedure called for warming the head to 200 deg. Unfortunately, the odor of “Safety-Kleen” solvent, which the head had been cleaned with, was brought out by the heat of the oven. Boy, was my friend’s wife, uh, furious (G – rating maintained). No oven baked or broiled food for a few days. Hey, you didn’t think I did this in my kitchen, did you?

    Fred DPRoNJ



    • shakes,

      Now that is an example of taste. To me, this job spoiled the look of the rifle. It is good work, but it’s not original.

      When I think of a classic restocking job I think of the work done by Al Biesen, a famous stockmaker of the past. But even he would have ruined the rifle if he had tried to restock it.

      Just my opinion. :)

      B.B.


  4. Nice report BB.I will be interested in seeing the velocity numbers,SD, etc., when you get around to testing. Betting that speeds and consistency will be improved. Nice compressor as well-I do all my guns up to and including a B-28(RWS 350) without one,but it certainly would be nice to have.


  5. Hey BB, I am glad to see you working on the 68. I think it is worthy of the time you are investing in it. I was surprised how nice the piston seal looked and at the condition of the spring. If you didn’t do anything but blast the trigger housing with WD40 until the gunk ran out and re-lubed the trigger housing I expect that would help it. I hope a little judicious stoning of the sear and trigger spring work will lighten the trigger up. The gun is too light to have a heavy trigger.

    Edith sounds like she is pretty patient with you using her kitchen table. I don’t think too many wives would go for that.

    My family and I am heading to Colorado this weekend and will be up there all next week. I bought a Hatsan Model 25 Supercharger pistol in 22 cal from Pyramyd Air for the trip. It’s always fun to have a new gun to play with on the trip. I also plan to take my USFT Hunter, one of the Gamo Survival rifles, and maybe an R9 I recently acquired. It will be nice to be able to get out and shoot without the 100 degree heat.

    David Enoch


    • David,

      I am glad that you get to see the inside of this gun, after owning it for so long. It’s really a nice shooter, and the trigger is definitely next on the list. But stoning the sear won’t work in this case, as the sear surface has very little to do with the trigger’s pull weight. It’s that long lever that magnifies the tension put on it by the piston when the gun is cocked. This is a case where I have to go slow, to avoid messing anything up.

      Enjoy Colorado! Edith and I met and were married in Denver, and we both know how nice it can be.

      B.B.



  6. B.B. is the one-man (and woman) publishing house. I can appreciate from some of my own projects that writing is only part of the story. Pictures, editing, research and more go into the final product. Wow.

    Desertdweller, you’ve only lost your concentration once in competition?! :-)

    I didn’t mean to sound condescending to Matt Emmons who is a heck of a shot. I’m reminded of an old movie about Michael Douglas as an elite marathoner who had trouble dealing with pressure. But he was so good, as one viewer said, that who cared about his tolerance for pressure. That’s great that Matt reaches out to others and that PeteZ has corresponded with him if that’s the case. But here indeed may be the crux of the problem. In the film Chariots of Fire, which is something of a theme for the current Olympics, there is a scene where Harold Abraham, one of the heroes is commiserating with a teammate, named Aubrey Montague, for a disappointing sixth place finish in the steeplechase. “You are my most complete man, Aubrey,” says Abraham. Aubrey is a really nice guy. Watching but remaining silent, Abraham’s hard-bitten professional coach is thinking that Aubrey is too nice and that he lacks the “ruthlessness” necessary for a champion. Maybe Matt Emmons was too nice on that final shot to crush the opposition for all time… Anyway, best of luck to him and his nice wife.

    BG_Farmer, agreed about the technological advantages of shooting. Maybe that’s why the ancient Greeks competed without any clothes. Also a disgruntled online commenter wondered why higher calibers and longer distances are not used at the Olympics. That’s a good question. I think they used to have a 300m high-powered event but it was cancelled.

    B.B. in describing the AR as the “most successful series of rifles” of all time you must mean their record in competition, their longevity with the U.S. military and their commercial success. All good indicators, I don’t deny. I tend to agree that they do great in everything except what they were originally designed to do… :-)

    Wulfraed and Mike, your point about the impossibility to generalize about the accuracy of ARs under rapid fire is unassailable. But. Speculation is always eligible. :-) What causes a gun to lose accuracy from prolonged shooting? No doubt the entire mechanism is involved in some way or another. But I would guess that a lot of the problem in the case of the assault rifle design stems from having the relatively short and light barrel combined with the high-powered cartridge. We know that pistons don’t prevent the AK from losing accuracy so whether an AR has a piston or DGI shouldn’t make much of a difference. On the other hand, the reliability which Mike noted is the AK’s forte by definition means repeatable performance, so the AK should tend to resist degradation in accuracy from heating better than the AR. Also, one of the issues with DGI is overheating through the mechanism, not just the barrel, and that surely won’t help. So my guess is that the AR would suffer a steeper decline in accuracy from rapid firing than an AK but given that the starting point of accuracy is higher, whether the overheated performance of the AR is better or worse than the AK is hard to say and probably individualized. :-)

    And just to show that I’m not totally negative about the AR, I understand that there are new coatings for the parts that make lubrication largely unnecessary. That material innovation alone might give new life to the DGI system.

    Matt61


    • Matt,

      Yes, I certainly did mean the ARs are a commercial success. As for their accuracy or reliability, that’s another story.

      However, giving the devil his due, the AKs and SKS’s are almost stone-reliable, but not so accurate. The M1 Garand is fairly accurate (the M14 even moreso) but not as reliable as the AK family.

      I guess like any shooter I want it all — accuracy, reliability and longevity.

      B.B.


    • The biggest reason that AK’s aren’t that accurate as a rule is that most of them have parts that “float”.
      That means lots of looseness in the action. AK’s can be made accurate, but reliability will suffer. There’s no free lunch. AR’s are very successful in fullfilling their original mission as a military weapon.
      The US Military and others are still using it with success after all these years. You only need to know how to maintain it to make it work. The original problems with the rifle were cause by stupid decisions by people that should have known better.

      They loaded the ammo with ball powder that was used in the 7.62 round. Why, to save money. The rifle was not designed to use that powder. Take a springer air gun and lube the chamber with motor oil and see what happens!

      The powder pushed up the cycle rate and was very dirty. Then, just for fun, they didn’t issue cleaning kits or teach soldiers how to maintain the rifle.

      There are other things but these two were the big mess ups with the M-16 as first issued.

      Mike


    • No, keeping concentrated is an ongoing challenge.

      I meant I got carried away with the importance of the event to the extent that it affected my performance. I think I was OK until the F/A18′s made a low flyover.

      Of course, that was just prior to the beginning.

      Les


  7. JM used to sell this spring as the “Vertex Dulcet.” I kid you not. I received one in a tuner’s grab bag, so I asked him about it. One neat feature is that by swapping ends, you can effectively varry the piston weight, since the closed coils function as dead weight. I installed it in a Kral underlever .22 with great results.

    I’m a little curious about your choice of this spring for this gun though. Fewer coils and thicker wire USUALLY (but not always) translate to stiffer cocking and harsher firing. Your noted increase in cocking effort seems to bear this out. I’m anxious to see the velocity numbers, and your opinion on firing behavior.

    My favorite JM spring for vintage and low powered stuff is the square-section “Merlin.” It has a smaller ID than a lot of his offerings. It also comes with a ridiculously high coil count, and can be easily shortened for many applications. I usually start with a coil-bound stack height (number of coils times wire diameter) slightly less than the spring I’m replacing, and go from there.

    Thanks for coming back to this one.


  8. BB, you really need to consider having a office/workshop built. You really need it. After all, it’s only money. The government prints more every day!

    Mike


  9. Hi,
    I was very pleased to find your write up this morning. I have what I believe to be the same rifle shown. My grandfather bought it new in the 60′s, I believe, and it is the rifle my brother and I learned to shoot with. It is probably the most treasured piece of family history I own. I am going to use your write up to tear it down and clean/lube it, but would like to know where I might purchase one of the TX200 springs referenced? Would also love to replace the seals but have had no luck finding them. Anyway, thank you for the article as it is going to help reintroduce the Gamo to MY sons!

    CW4 Darren Reese


    • Darren,

      Congratulations. A Gamatic is rarer and more desirable than the single shot I’m showing here.

      That mainspring isn’t a standard spring for a TX 200. It is a special spring custom wound by Jim Maccari, AKA the Springman. I got it 15 years ago and I don’t know that he still makes them. His website is Air Rifle Headquarters.

      If the spring in your rifle is still in good condition I would leave it in place. Replacing it detracts a bit from the value of your collectible gun.

      Welcome to the blog.

      B.B.




  10. My father passed away not too long ago and while going through his things, I came across his Gamo 68 that he taught me to shoot on when I was a youngster! Brought back memories for sure. Unfortunately, time has taken it toll on the 68 and Im interested in getting it back in proper working order. Im really glad I found this blog, answers quite a few good questions about where to begin the process.
    The gun seems to fire perfectly, but is missing the entire rear sight assembly, and is obviously rendered nearly useless without it. Anyone out there know of a replacement, original or even aftermarket that would work?


    • A. Wheeler,

      That rear sight will be peculiar to El Gamos of this period. The model 300 is a conventional rifle with the same metal parts, so the same sights.

      Try this guy for parts:

      John Groenewold, PO Box 830, Mundelein, IL 60060-0830, (847) 566-2365
      http://www.jgairguns.biz

      B.B.


  11. I have a EL GAMO GAMATIC that needs a few little parts. Do you kniw where l can get them… it is unmolested meaning all stock never been drilled for scope or modified in any way. It was bought for me when l was about 10-12 yrs old and l am now 50…


    • Harold,

      Welcome to the blog. You hasve posted to an older report and only a few of us will see it. You can always post any question to the current blog, which is here:

      http://www.pyramydair.com/blog/

      As for Gammatic parts, good luck! Of course id all depends on what parts you need. Springs and seals are nearly universal and can be made to fit.

      If you need specific proprietary parts I think you need a donor gun and Gammatics aren’t that common. This man might be able to help you:

      John Groenewold, PO Box 830, Mundelein, IL 60060-0830, (847) 566-2365
      http://www.jgairguns.biz

      B.B.


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