GTA
All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => Spanish AirGun Gate => Topic started by: Mossonarock on October 19, 2023, 08:39:58 PM
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By popular demand, I'm posting a thread about how I remove the trigger from a Marksman0035, also known by other names such as Beeman0035. The challenge with removing the trigger group from this gun is that the bracket that holds the trigger components together is L shaped. So somehow you have to compress the spring without pushing against the trigger group/bracket. To do so, I made an adapter for a scope rail mounted spring compresser. Its really nothing more than a block of wood with a strategically placed hole for the compressor on one side and a 2inch L bracket on the other side. The L bracket is 5/8inch wide and that's kind of important to know. The 2 inch leg of the bracket is just long enough to by-pass the trigger group and make contact with the base of the spring guide and compress the spring enough to get the trigger group out. The metal on it is also thick enough that it doesn't bend while compressing the spring. We're lucky this is a weak spring and let's us do this safely.
First step: There isn't enough clearance for the L bracket to slide under the trigger group at first. So you need to remove the retaining pins first in order to free the trigger group but you won't be able to remove it just yet. So I first I place the wooden block side-ways between the spring compressor and the back of the trigger group. You'll notice that the back end of the trigger group bracket extends a couple mm's beyond the gun's compression tube. Apply just enough pressure to it so you can tap the retaining pins out.
Step two: Now that the trigger group is freed, you can wiggle it around to give the L bracket the space it needs to fit under the trigger group. Turn the adapter so that the L bracket fits under the now freed trigger group and place the spring compressor contact thing in the hole of the wooden block. That hole is necessary to keep the spring compressor contacter from sliding all over the place. And now begin compressing the spring as far as the L bracket will let you. Once you have it all pushe in, you can wiggle the trigger group out.
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I hope that all makes sense. The pictures are in order of operation.
I also wanted to mention something about the trigger. A lot of people complain about how terrible this trigger is. Mine was really rough too. When I first took the trigger out, I found out why. The bracket that holds the trigger components together was all bent out of shape. I suspect that was actually deliberately done during manufacturing. This is why: I straightened out the bracket using a table vise and that smoothed out the movement of the trigger. However, when I assembled the gun back together, the seer would barely engage with the piston. Sometimes it wouldn't engage at all. Somehow straightening out the bracket somehow moved the seer back just a little bit. That made my gun extremely dangerous as it would shoot at any random time even with the trigger safety on. The trigger safety only blocks movement of the trigger. It doesn't block the movement of the seer. So, I took my gun apart again. Then ground about a mm off the seer whilst being very careful not to change the geometry of the seer. Now the seer engages everytime and the gun no longer randomly shoots without pulling the trigger. However, the seer will release if the butt of the stock is knocked hard enough. I'm not sure if the gun every did that beforehand but it probably did and I just never had that happen. So, its still a very dangerous gun. I think the manufacturer bent the brackets in order to get the seer in the right position to engage with the piston, rather than correct their design errors. But hey, my trigger moves real smoothly now.
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One more pic.
I replaced the oem front sight with a sight made for the famous M1 carbine from WWII. The barrels' outer diameters are very close to being the same. The 0035's is a wee bit smaller. The fix the sight to the 0035, I drilled and tapped a hole in the top of the m1's sight to fit a grub screw. Tightening down the grub screw holds the sight in place. Its possible I might have ground a divot or flat space on the top of the barrel to accept the contact from the grub screw but I don't remember. So, now I have a solid metal front sight tough enough to handle battlefield conditions. I removed the rear sight and replaced it with a Williams peep sight. This sighting set up really makes the gun fun and accurate to shoot. I believe the proper name for such a front sight is "winged partridge sight." I'm a total fan of it. The visibility of the front post is way better than in an enclosed globe sight and no silly optical fibers are needed.
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Hmm
Tim,
I can see what I used for taking apart another rifle probably isn't "generic enough" for this one...
https://www.gatewaytoairguns.org/GTA/index.php?topic=102737.msg971316#msg971316 (https://www.gatewaytoairguns.org/GTA/index.php?topic=102737.msg971316#msg971316)
It might work but will be clumsy
Looks like the best way is with two pressure points, one on the back of the trigger group to hold it while pins are removed - would have to "originate" from the bottom. The second some fork or bar (like your bracket) to push past where the pins were removed.
I wonder if part of the trigger group bend was having the spring pushing it rearward against the back opening for it in the receiver. Nice save on the geometry fix and sear adjustments :D
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To summarize, I found that a two-step process to remove the trigger group is necessary. The first step is to remove the retaining pins. The second is to remove the trigger group.
The first step only requires a bit of a nudge to take the pressure off the pins. They may be very stuck in there and a bit of hammering may be necessary to tap them out. And the pins can only be removed in one direction. They have some knurling on one end for traction I suppose to help them stay in place. So try to remember which direction that was for when you go to reassemble the gun.
With the pins out, the trigger group can be wriggled about a bit to give yourself some clearance to push against the spring while not pushing against the trigger group. For the step, the spring needs pushed forward at least 2inches whilst not applying any pressure against the trigger group.You can't have any pressure against the trigger group for this step or you can't get the trigger group out. With the spring pushed fully forward out of the way, the trigger group should be fully loose in the compression tube cavity. You can then lift the trigger group out.
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I wonder if part of the trigger group bend was having the spring pushing it rearward against the back opening for it in the receiver.
I don't think so. The spring isn't that strong. I think they muscled the trigger group bracket to get the right seer to piston geometry. A brutish way to solve the problem which only created new problems- rough/stiff trigger pull. They ought to have revised the engineering plans. Or fire the bugger who was drilling the holes wrong, whichever the case may be.
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Can you provide the specs to the mainspring. Wire size, coil count, inside and outside diameter?? Thanks.