Idiots guide to classic airgun strips (pt 1)

[Citizen33]

I dug the Merlin out of a box. I intended to strip, varnish and spray it with placticote when I move, but the Idiots guide got the better of me. I dont really know how to describe the strip and the Chambers page isnt much use but here goes.Take out loading tap and put in safe place!
Undo and remove front two stock screws and the one at the rear of the trigger guard (its like a woodscrew as it goes into plastic end cap). As you lift action out of stock, the sliding plate attached to the cocking lever will slide backwards until action can be lifted out. On mine the trigger guard came up and out with the gun, but it may well remain in place. The end cap slides out of the rear of cylinder with the trigger spring (note how the spring sits in recess in plastic). The trigger then slides out of cylinder. If you remove the cocking lever pivot pin (WATCH OUT FOR THE SPRING THAT SITS IN THE MIDDLE) then all the cocking lever stuff can be removed. There didnt seem any point in stripping that further so I just put a bit of GN paste and LT2 round it. To remove the mainspring and piston, you have to remove the funny spring clip at the rear of the cylinder that this gun has instead of a pin. GO TO NEXT POST.

Thanks to Ggggr for his useful posts on the Merlin. Being more stupid than the average idiot, there were a couple of points that weren't clear to me and I thought more detail would help.

As you lift the action away from the stock one thing to be aware of is that the lever axis pin may be loose enough to drop out if you turn the assembly sideways, causing the safety sear and spring to fall out and leaving you unsure of their orientation (this is what happened with mine). The other thing is that once the end cap screw going through the trigger guard is removed, and you lift the action away from the stock the plastic end cap may pop out, letting the trigger spring fall out, and again leaving you in doubt about the relative positions. My advice would be to slowly lift the action a couple of inches from the stock and examine the positioning of these parts before you try to get the lever and sliding plate out.

The safety sear sits with the closed side towards the action and the long thin spur towards the barrel. The end of the spring with twin prongs sits inside the closed part of the sear and the end with a loop is tensioned against the trigger guard, which you will have to position carefully on top of the spring when you re-assemble. Putting a small hook through the looped end of the spring may make re-assembly easier.

The long end of the trigger spring sits behind the trigger (facing down and parallel), while the short end with bend is positioned in the square hole on the front of the plastic end cap.

I have made pdf diagrams of both assemblies, and also have a very helpful collection of photos from member Isobar (whose help was crucial in letting me fix my gun). I'm happy to forward these via pm, or if a moderator wants to add them to the thread will supply on request. I do not appear to have posting rights for images. As Grrrr noted, the diagram on Chambers' website isn't very helpful and doesn't show the safety sear.

[ggggr]

The ASI/Gamo Center pistol is an underlever cocking pistol with a plastic plate/loading tap that flips out of the side. It is a better version of the Gamo Falcon (which apparently came later at a cheaper price) but has no safety catch. The Falcon (if my memory is correct) had a crappy plastic lever located by a small spring and a bb.
The Falcon also had a plastic frame which made it seem very crappy, almost like an RO72
The Center has a fairly decent die cast frame. You can also adjust the angle of the grips by undoing the screw on the underside of the pistol grip and swiveling the grip into place before tightening the screw again. The trigger is adjustable via the smaller of the 2 screws at the back of the trigger guard, although you have to undo the larger one a little first as it bears on a piece of spring steel that locks the smaller screw into place.
The example of the gun I have had a crude homemade rearsight and someone had fitted a .22 barrel and drilled to loading tap to suit.
Ok--here we go. Remove the rearsight if you want. To make things easier, undo the screw on the underside of the pistol grip and then remove the upper of the grip screws. This will enable you to remove all the pistol grip (for ease). The frame is fastened to the cylinder by 3 screws, one at the back and 2 at the front. Undo these and remove the frame.
You can knock out the cocking arm pivot pin and remove that if you want. If you want to remove the loading tap, the is a screw at the front of the breech block, next to the barrel. If you are doing a fullish strip down you may want to do this to change the breech seals or the O ring on the transfer port insert (More later). Put pressure on the endcap and remove the cylinder end pin and release pressure to remove the endcap/guide, mainspring and then piston. The piston washer is a leather one, with a plastic buffer, held on by a crosshead screw. With the guide,spring and piston out, if you shine a torch down the cylinder you will see the transfer port insert. If you wish to remove this (it has a small O ring on it to seal it) then you will have to undo the grubscrew at the front underside of the cylinder. This locates in a groove on the insert. With the screwout, you should be able to use a small rod or something to push it into the cylinder. The O ring that seals the breech will probably remain in place. There is also a seal on the barrel side as well if you want to change that.
Clean and lube your bits and go to pt2.

[ggggr]

Assuming you have removed the transfer port insert for a look and maybe fitting a new O ring on it, you will want to get it back into position. I managed to drop it into the cylinder, get it into place and then push it with a dowel. I fitted the piston, mainspring and guide before refitting the loading tap, but I think doing the tap first is a better idea as it might be tight if you have fitted new breech seals. Locate the loading tap and locate and tighten its pivot screw. If the tap is tight, due to new seals, then you can wangle the transfer port insert a little. Once you are happy with it, replace its locating grub screw on the underside of the cylinder. Replace your piston, mainspring and guide/endcap. Put some pressure on the endcap and push the cylinder pin through to locate it. Replace the cocking lever and locate the cocking arm into the cylinder and then put the cylinder onto the diecast frame and replace the 3 screws that hold it. Replace your grips and replace the top grip screw. Swing the grips to the angle you want and then tighten the screw on the underside of the pistol grip. Replace your rearsight.

I have not had a chance to try the pistol since the strip and I guess it will not be too accurate with the crude rearsight. It does however seem a fairly well made pistol. I have not checked the spares situation and did not remove the trigger components, but did notice a little wear on the pins, where the cocking arm had rubbed.

[ggggr]

This one must be a fairly late one. It has the "saddle" rear sight, a cast foresight, 2 piece cocking arm and a trigger unit. The one I got was missing the spring guide, mainspring and cylinder end cap. The cocking arm was damaged at the front, which I guess was caused by brute force trying to get it out of the cylinder The pins and screws on the trigger unit had corrosion, so although I managed to get the pins out and lubricate the sear and trigger, I cannot adjust the screws
If you want to remove the foresight, you will have to take the protector off to get to the screw that holds the sight on. To remove the rearsight, knock out the split pin that secure the sight to the breech block, remove the elevation wheel and the sight will lift off. Watch out for the little spring underneath it.
Undo the 2 front stock screws and the front trigger guard screw and the action will lift out of the stock. The cocking arm will lift out of the cylinder. You can remove the pivot pin and lubricate the arm,pin and slot if you want. Knock out the barrel pivot pin. If you want to remove the barrel plunger and its spring, you need to push the plunger in and undo the little grub screw on the LHS of the block. Once you have lubricated it, replace it. (I usually use a small piece of wood to push the plunger instead of just my thumb).
Remove the cylinder end cap and the cylinder end pin and the trigger unit will come out. I would suggest getting some penetrating oil on all the trigger bits as they do seem to suffer from corrosion.
A steel ring that located the front of the trigger unit in the cylinder should also come out of the cylinder now. Using the forked bit of tube often mentioned on this thread, keep pressure on the Plug (for want of a better word) in the cylinder and undo the nut that locates it. Release pressure and the plug, guide and mainspring will come out. The piston can be removed now as well.
The piston washer is held by a forked nut. I didn't attempt to undo the nut as the piston washer was in good condition.
Clean up the bits, lubricate them and go to part 2.

[ggggr]

With all your bits cleaned and lubricated, replace the piston, mainspring and guide into the cylinder. Place the plug into the cylinder with the spiggot side facing upwards (so it will be on the trigger unit side). Compress the mainspring with your bit of forked tube and locate the plug and secure it with it's nut. Now replace the steel ring into the cylinder before replacing the trigger unit. (You will see the front of the unit should sit between that and the little spiggot of the plug. It seems a crap idea but this one seems better than the G79's I've seen). Locate the cylinder end pin through the cylinder and the trigger unit. Replace the barrel into the breech jaws and locate the pivot pin. Place the end of the cocking arm into the cylinder. The action can now go back into the action or you can replace the sights first. Secure the action in the stock with the 2 front stock bolts and the rear one in front of the trigger guard.
This doesn't seem a bad little gun. It shoots ok, although down in power with the spring I fitted. It does have that crappy "what if" Milbro feel about it though. Like I have said the trigger pins,circlips and screw seem prone to corrosion, but maybe that is just 35 years of neglect? The sights seem out of line--with one side of the rearsight body higher than the other and the foresight is off centre as it just has a screw to hold it and no locating peg as well.

[ggggr]

I finally got my hands on one of these and decided to strip it tonight. I am stuck for a barrel pivot lock nut and have asked on of the bbs good guys to help out.
This is a basic pistol and oddly seems to share no parts with the Relum Hurricane underlever pistol


The is a big screw that passes through the pistol grip. If you undo that, the action will lift out of the grip.
With the action out, you can tap the trigger pivot pin out of the housing and remove the trigger. Do the same with the sear pin and slide that out the back of the housing, watching out for a sneaky little coil spring (mine didn't have one but I found something suitable when I put the gun back together) that sits between the underside of the sear and the trigger housing. There is what appears to be a 3mm trigger adjusting screw in a lug, if you want to clean and lube that.
Knock the cylinder end pin out and remove the endcap and mainspring. There didn't seem to be a lot of pressure but I am not sure it is the right mainspring.
Undo the barrel pivot lock nut (if your pistol has one, unlike mine). and remove the breech block from the jaws. You should now be able to push the cocking arm backwards in the cylinder until it will lift free (like a BSA Cadet or Major). The piston can be slid out now.
If you want to clean and lube the barrel catch plunger, knock the little pin holding it out and remove, clean, lube, replace now.
It is interesting to note that your barrel may slide out of the breech block as is seems to be secured by the barrel pivot bolt. If it bothers you, a little thread lock could be used I suppose.
I didn't remove the little grub screw on the underside of the cylinder that hold another plunger as I did not think it was worth doing.

The piston has a leather piston washer held on by an aluminium rivet. It was a bit loose so I spread the rivet a bit.
Clean everything and go to pt2

[ggggr]

With everything cleaned and lubed, place the piston into the cylinder. You will then have to slide the cocking arm through the trigger housing until it drops into the cylinder and piston and then pull it towards the front on the gun. Locate the breech block in the jaws and replace the pivot screw and lock nut.
You can replace the mainspring, endcap and cylinder end pin now.
Locate the trigger in the housing and locate its pin. Place the sear spring in the recess in the sear and slide the sear into the housing and then compress the spring a little to enable it to go into the housing. Replace the pivot pin.
Put the action into the grip and replace the big screw through the grip.

My gun needs a new mainspring as the old one is very tired.
I have not plinked with the pistol yet, other than 2 shots when I got it. The rear sight is a bit like a BSA cadet type, that is not adjustable for elevation. This is different to the spring steel one in the gun that was featured in the March 2016 AGW.

I still find it odd that the break barrel and the underlever share no parts. Even the shoulder stocks are different in length, width and shape.