Idiots guide to classic airgun strips (pt 1)

[ggggr]

I got sent one of these not working last week---------didn't want it, don't want it but decided to look at it. This is the thing that looks like the Colt automatic and is very similar to the Marksmen version. A version is still being made and is sold by SMK https://www.gunspares.co.uk/products/24504/G10/
A search of Youtube will show you a strip---but this is more of the nitty gritty
If you push down on the cocking slide button and pull the cocking slide backwards, you should be able to pull put the little clip that looks like a bike chain split link, with a pair or long nosed pliers. You can then gently lever the slide out of the sides of the pistol and remove it. There are 3 screw on the RHS of the pistol that need removing before you can lift the RHS away. If you are unlucky, the mainspring unit will flt out and the trigger spring will flip up and out as well
Anyhow--if it doesn't, compress the spring unit from the barrel end towards the back (There is a little extension that locks the barrel so this end needs to come out first) and take it out. You can lift the sear off the trigger, remove the trigger, trigger spring and the safety (if they haven't already jumped out!). I'll deal with the piston mainspring unit at the end. They now come as a unit if you can get them.
To put the gun back together, replace the safety, then put the hairpin spring on the pin, replace the trigger and then tension the spring. The tricky bit is the legs of the hairpin spring need to cross over, so the bottom leg is pushed up above the trigger and locates on the bar for it on the trigger. Replace the sear on it's pin and make sure the other end is on the pin on the trigger. Now the difficult bit---replacing the mainspring unit in the frame!. Push the back of the spring into the housing and compress it enough so the prong on the thing that passes for a cylinder, will then go back to locate the barrel. In theory you should be able to drop the RHS of the frame back on and repalce the 3 screws. I spent 45 minutes doing it, chasing the springs round the kitchen. It was due to the unit being worn and kinked. I think if you got a thin piece of aluminium and bent it over you could keep the thing in place until the RHS was almost in place. Replace the slider then locate the rod bit of the mainspting unit in the slot and replace the spring link. You will probably have to pull the rod out with long nosed pliers first to make it easier.

On mine the rubber piston washer was split and you cannot get them on their own. I got a piece of leather and put it in warm water, then punched out a hole in it (took 2 goes to get the right sized hole that would stretch over the boss on the piston head, when wet. I then roughly cut it round while it was on the piston head and then squeezed it between my fingers to form it, then put it in a bit of tube to take the shape better, before putting it in the "Cylinder"! which is VERY THIN WALLED brass. It could easily deform, which is why I would suggest another bit of tube first. I was only doing this as you cannot get the piston washer. IN the morning when it was dry, I oiled it and fitted it. The pistol works and will fire pellets, darts or bb's in the repeater mode. They are very low on power, not that accurate and I've never been keen on bb guns/repeaters where you cannot tell if there are any left or not. Anyhow--if you have one, want to strip one, you are in with a chance.

[Shed tuner]

just done a vid for a stripdown of the park rh93 recoiless air rifle.. rh91 is exactly the same.

https://www.youtube.com/watch?v=lxms2G3JT8A


Will do the rebuild when I get 30 mins...

[Phil Russell]

HAENEL Mod III DRP
The rifle being looked at is a Haenel Mod III DRP. There number 11 30 is under the barrel near the breech block, which makes me think it is November 1930. Barrel also states Made in Germany. I found no other numbers.
Overall the rifle looks quite good with a firm lock up and little signs of wear anywhere. There was a small split to the underside of the stock extending from the cocking lever slot to the front trigger guard screw hole but this has now been glued. A first fire showed the rifle to be pretty smooth but with a bit of noise. Output was tested with .177 Superdome at 593fps / 6.5ftlb. A tissue test of the breech seal showed no evidence of escaping air. I felt a strip and service was required as performance should be a bit better.
Remove trigger adjuster screw, noting how far it is screwed into the guard. There should be a lock nut on it. This is necessary to access the front trigger guard screw which holds the stock to the action. Remove the front trigger guard screw. The rear screw is a wood screw into the stock so can remain in place. Remove the two screws in the for-end and lift action out of stock. Tap out the trigger pivot pin, noting the trigger spring being present. Take care to hold it as you remove the trigger and it won’t ping away. As the trigger end block has a retaining bolt I put action in a compressor. Remove the retaining bolt (9mm spanner). The end block screws out of the action and I had to use a small bar inserted in the trigger slot to set it turning. It needed little persuasion. To aid turning I used a punch through the holes for the trigger pivot pin. Not knowing the preload, I left the action in the compressor while I undid the block; spring tension was manageable at the end of the block thread but still present. Remove block (spring guide is attached) and the spring. To remove the piston I released the cocking arm from the breech block; a retainer screw plus a pivot screw. Lift cocking arm away. I could see no fault with the barrel latch mechanism so left it alone.
With the cocking arm removed, extract the piston. The leather piston washer diameter I measured was 29.5mm but had seen better times. It is retained with a screw and an inner leather washer into the end of the piston. At some time it had been fitted with a brass ring under the screw. This was badly corroded with blue gunk. Washer leather thickness was 2.9 / 3mm as a standard cup with c 8mm sides. I made a new washer, (using Neatsfoot oil as a soak during formation), ditched the brass ring and used another small steel washer to set the screw level with the outer edge of the leather washer to avoid a gap.
Looking inside the cylinder with a torch, I could see blue gunk at the end so cleaned it all out and gave it a quick polish.
I had previously found spring dimensions from Internet to be c 21.3 mm (0.84”) od, 3.27mm (0.127”) wire and 200.7mm (7.9”) long with 28 coils. The spring I removed was just about spot on these dimensions. I thought of adding a piston liner but judged the spring to not have sufficient clearance to do this. There was some scuffing on the rear edge of the piston which I polished out. I added a steel slip washer inside the piston.
Reassembly was a simple reversal of strip down. Piston with new leather washer was inserted in the cylinder using a few drops of SM50 on the washer as the piston went in. Piston body was lubricated with a smear of moly grease, as was the mainspring, spring guide and trigger block threads. Back into the compressor and the trigger block wound in until it was possible to engage the threads. When fully wound in, replace the block retaining bolt. If it gets stiff, stop and adjust the trigger block a tad. Replace the cocking arm; engage the end into the cocking slot, making sure the arm moves freely in the slot then fit the end to the breech block with the screw and keeper screw.
The trigger is then replaced. Put trigger spring in the trigger recess and then fit the other end into the recess in the rear of the block. These recesses are quite deep so there is little danger of the spring escaping while you manipulate the trigger down into the slot against the spring pressure. I found it easy to look through the trigger pivot hole to see when the trigger was in position then use a parallel punch to hold it all together while the trigger pivot pin was added. Make sure the trigger moves freely against the spring pressure. If not, remove pivot pin and try again.
Add a smear of moly to the cocking slot and the barrel release mechanism then replace action in the stock. Replace trigger adjusting screw. This acts directly to change sear engagement so do not screw in further than the screw was originally set. A test shot of the now very smooth serviced rifle gave one clearly ‘diesel’ shot but then settled down to a healthy 652 – 657fps for c 7.9 ft lbs. I expect this to improve slightly as the new piston washer beds in and settles down.
Cheers, Phil

[Garvin]

https://forum.vintageairgunsgallery....tol/#post-4252



LeonardJ provides these pics:





PS Len made these observations when he stripped a Hy-Score:

"One of the more unusual features, for any spring gun, is the presence of a lubricating wick on the piston head. The next thing that becomes apparent, in spite of being a concentric piston action (barrel runs throught the center of the piston), there is no seal present between the ID of the piston, and the barrel - just a very smooth, close tolerance hole through which the barrel passes - the lubricants form the seal. The piston head is fastened to the skirt of the piston in a manner that allows the head to "float" - no doubt to help maintain a seal. The spring guide also "floats" within the confines of the mainspring ID. The gun uses a common O-ring seal on the piston head, and a proprietary seal within the rear end cap, which seals the main compression tube, so that all the compressed air is directed to the breech, and thus to the pellet."

[Phil Russell]

Gem Style, no maker’s name. Most likely a model 13A from Eisenwerke Gaggenau (Iron Works, Gaggenau)
No. 57748 inside breech with numbers 748 or just 48 on other major parts. This rifle, .177, had been languishing in a cupboard for a long time. No makers name: overall 34” with 17.5” barrel, round but with a top flat. Barrel latch operated by a sprung lever on top of cylinder which, when pressed, allows the barrel to open.
Full of anticipation I tried a test shot; pellet only went about 1” down the, smooth, bore. Time for a service. I removed the screw bolt at the rear of the action near the front of the half stock. This pulls the sides of the cylinder together to nip on the thread of the cylinder / stock plug, holding the stock in place. Removing the bolt allowed the complete stock to unscrew from the cylinder; this gives access to the mainspring. There was a fair amount of preload, maybe 2”. When new I suspect the spring to be 8.25”, 37 coils of 2mm wire 15mm od. The rifle’s spring was about 1” shorter. Remove trigger guard /cocking lever by tapping out the pin at the front of the guard. Guard can now be removed to the rear of the action, bringing the piston with it. My trigger guard pin was bent so a new one was made from a suitable HSS drill shank. The piston rattled its way out of the cylinder. I was surprised to see a huge sealing washer about 9.5mm thick on the end of the piston. There was a steel washer secured by a peened over end to the central rivet rod, 8mm approx. diameter. There was no visible means of removal so I concluded the unit had been ‘rivetted’ into place. As I wanted to get the rifle working, I decided that a new washer would have to be fitted even if this meant sacrificing some of the old central rod/rivet. I decided not to attempt driving the rivet/rod out so removed the peened end to allow the end steel washer and piston seal to be removed. A new leather washer was fitted by tapping the end of the original rivet with a 4mm thread and screwing the new washer unit into place with a delrin spacer to give the same length of piston washer unit as original.
A new leather breech seal was fitted, 10.5mm od x 2.4mm thick with a 3.5mm hole punched in the centre. It is possible that the old seal could have been saved by a good soak in neatsfoot but I decided to do a new one.
The barrel release catch was a bit loose on its mount on top of the cylinder but after a failed attempt to tap out the pivot pin I decided to leave it alone: the pin was very firmly stuck and the catch worked OK as it was. Similarly I did not remove the trigger parts as I saw no need to. All are retained by pins. The trigger can be adjusted by a small screw on the trigger blade that adjusts sear engagement. It was loose so I put a drop of mild Loctite on it. I intended to remove the stock from its steel end plate but only one screw undid so I left it alone.
I lubricated and reassembled the rifle with the original spring and was pleased to see c. 340fps with Geco wadcutters and c. 320fps with AA Field. To satisfy curiosity I removed this original spring and tried a spring of the same specification that was about 1” longer. It made no difference other than being harder to fit. So I put the original one back.
All I all it was great fun despite the piston washer surprising me. I wonder if all gem style rifles are like this?
Cheers, Phil

[Phil Russell]

MILLITA ORIGINAL V
Serial No 105327 with the numbers 5327 marked on virtually all individual parts. Outwardly very good but with two clear faults; the rear sight was missing the adjuster wheel (although the sight element was present) and the barrel release catch was loose which meant the barrel would not stay fully closed. Time to delve a bit deeper.
To strip the rifle it is not necessary to remove the butt from the trigger block but if you wish to do so then remove the two screws holding the steel butt plate in place and then undo the nut visible at the base of the hole. You will need a box spanner, most likely 17mm. I left the butt in place.
Remove the trigger guard, two screws into the action, a wood screw into the butt. There is no need to remove the adjuster screw … my adjuster was missing a lock nut but I found a 2BA one fitted very well so oil blued it and fitted it. The trigger is held by a pin through the end block. My pin was very tight so I left it alone, having ascertained that the trigger functioned as it should. The trigger block unscrews from the action but if you have not removed the trigger, you need to pull the trigger back to clear a cut out in the action in order to allow the block to unscrew. Take care when nearing the end of the thread in case the mainspring is strong. Mine was not, with only about 3cm pre-load. The mainspring lifts out. To remove the piston, release the cocking link by removing the screw at the pivot and lift the link away. It helps to ‘break’ the action. Remove the piston. The piston head was in terrible condition. There had been a leather washer but only half remained and there was a doubled over 4cm flat nail embedded in the remaining half. It was secured by a central screw which I suspect was a replacement as the screwdriver slot was off centre. I could see no evidence of a leather cup shape to the washer, just a disc. I made a new leather disc washer from 6mm leather hide and found a new retaining screw which I fitted with a steel dished washer countersunk into the leather disc. The leather was trimmed to just proud of the piston outer edge and left to soak in neatsfoot oil while I continued the strip.
Remove barrel with action broken by removing the keeper screw on the pivot bolt and then unscrew the pivot. Barrel just lifts away. To remove the barrel catch, drive out the pivot pin, approx. 5.5mm diameter. Mine was very tight and, I suspect, a replacement because the small spring that activates the catch was far too weak to do the job. The catch and spring just lifts out; it will only fit back one way. I found a much stronger spring approx. 12mm long x 5mm od and which fitted in the location holes in the catch and the breech block. A test showed it to work perfectly, restoring a positive barrel fitment.
The breech seal seemed quite OK so was not touched.
Attention turned to the rearsight. I hoped to find a replacement screw that could be modified to form an elevation adjuster but failed. The required thread was clearly very fine and I failed to match it. Purists look away: In the end I made a new adjuster from Delrin and used the thread on the sight base as a die to slowly cut threads in the Delrin. It took a while but was successful.
Rebuild was straightforward. Parts were lubricated as necessary during the rebuild. I started by assembling the barrel catch then refitting the barrel/breech. This is easier with the action in the broken position. Close the action and test tighten the breech pivot bolt to ensure you get a good nip on the breech while still being able to fit the pivot keeper screw. You can adjust this by the use of a shim under the bolt head but this was not needed. Assemble piston (with a little grease on the body ends) in the cylinder making sure the cocking slot aligns with the cylinder slot. Replace spring (lightly greased as required) and refit the trigger block / butt assembly. This is not the easiest job in the world and I clamped the action in a padded vice for stability while I engaged the threads on the trigger block with the action. Take care not to cross threads and remember to pull the trigger to allow the block to seat fully. Replace trigger guard.
Testing with various pellets produced velocities ranging from 486 to 508 with excellent consistency for any particular pellet. This is, I believe, about on spec according to data published by BB Pelletier (Tom Gaylord). Overall, I am quite happy.

Note: Quite by chance I found pictures of this exact rifle on Garvin's VintageAirGun Gallery.

Cheers, Phil

[Phil Russell]

Diana / New Champion 1905 Patent Model.

Also known as the MGR 1905 model. John Atkins has told me that to call it a Diana is not strictly correct as the Diana name was not registered here until 25 April 1907. Outwardly it is very similar to other break barrels of that era with a stock secured to the trigger block by a long through bolt and the trigger block screwing onto the cylinder. There are, however, a few significant differences which will be mentioned as we go through the strip and rebuild procedure. Maybe the most obvious is that the cocking link moves in rails fastened to the top of the cylinder. The LH side of the breech has the word PATENT stamped towards the top. Underneath this is a stamped circle with the letters MG over R. No doubt for Mayer and Grammelspacher of Rastatt, Germany. The lower flat on the octagonal smooth bore barrel near the breech is stamped ‘Manufactured in Germany’. The front 19.5cm of barrel is round. The name Champion / New Champion was apparently given to models imported into the UK, but does not appear on the rifle. Serial number of this model is 2102, stamped on the breech face visible after breaking the action. Research suggests this is a ‘Heavy’ pattern of this rifle; a ‘Light’ pattern, slightly smaller was available.
To strip the action: remove trigger guard, 2 screws/bolts. Remove trigger by knocking through the trigger pivot pin and lifting away the trigger and its spring. The trigger adjuster screw is mounted in the trigger, not through the trigger guard as on similar construction rifles e.g. pre-war Diana 27. Note that this pin is a tapered fit in the trigger block. The trigger spring on this model was very bent so a new one was fitted, using the old one as a pattern. Remove steel butt pad, two screws. Undo the nut inside the hole in the stock; a 17mm box spanner will most likely be necessary due to the depth of the nut in the stock. Note the washer under the nut. Pull the stock off the trigger block. Do not twist the stock to get it to come off the long through bolt as there is a spigot on the trigger block that goes into the stock; twisting the stock at this point will split the stock. With stock removed you can unscrew the long through bolt if you wish but it is not essential.
Unscrew trigger block from the cylinder. There could be reasonable preload so take care. I clamped the cylinder in a padded vice and wore a leather glove to unscrew the block; it was stiff to start. With the block removed, remove the mainspring.
To remove the piston it is necessary to remove the cocking link. I removed both the barrel and the link by removing the two screws. The link needs to be carefully lifted away from the guides on the cylinder after being folded back almost 180 degrees while at the far end of the cylinder slot. The piston can now be slid out of the cylinder. Note that the cylinder is threaded on the outside where it screws onto the trigger block meaning there is no danger of the threads damaging the piston seal when the piston is replaced.
The components were cleaned and the rifle re-assembled with suitable lubrication. This is a direct reversal of the strip procedure: assemble piston and mainspring in the cylinder followed by screwing on the trigger block. Attach barrel and cocking link. Reassemble the stock through bolt, replace stock and secure with the nut; remember the washer under the nut. Reassemble the trigger and spring making sure the spring locates in the trigger recess and the recess in the end of the stock. It is easier to fit the trigger using a suitable drift and then fit the trigger pivot pin once it is all aligned. Refit trigger guard.
A few facts: Rifle length 106cm. Mainspring was 250mm long, 18.7mm od, 2.8mm wire and 38 coils. It was quite straight. Piston 28mm diameter, 140mm long including head, weight 227gm. Cylinder od 32mm, trigger block od 38mm. Barrel octagonal 28.8cm measured from end of breech jaws then round for 19cm to muzzle. The piston seal looked good, being leather about 6mm thick secured by a central screw. Breech seal looked good. After this service rifle put out 8.4gn AA Field at c 610fps for c 6.9 ft lbs. Quite Happy.

Extra: The barrel detent engages with a plate fixed to the end of the cylinder by a 3mm grub screw which passes through a spigot on the plate that goes into the cylinder end. On this rifle the plate was a little loose and the securing grub screw was unable to be tightened or removed due to stripped threads. It was removed and replaced with a new grub screw, resulting in a firmly fixed plate.
Cheers, Phil