Making a new seal and fixing up a classic Diana Model 27

What’s all the fuss about this middle-of-the-road air rifle? Let’s find out together.

Oh dear this does not look Good welcome back to canicare what I have here is arguably one of the all-time classics in air rifles and yes it’s yet another 177 caliber spring piston gun that I can’t mount a scope on how do I need another one of those in my collection well this is a Diana

27 um as I said it’s considered a a classic and I sort of understand it when you pick one up it seems to be the the right side and shaped for an air rifle it’s uh it’s not too big not too small it uh clearly you know would work well

For a youth uh oriented shooter you know somebody who doesn’t have the the uh upper body strength to [ __ ] anything monstrous or um or has a shorter arms and doesn’t need all the length of pole makes it difficult to get their eyes down to the sights so I said this is a

Model 27 the Diana made for uh quite number of years there were some pre-war versions post-war versions I believe they stopped making them sometime in the 1980s I’ll look that up for you um this one here though is sort of a Diana um marked right on here it says British

Made Diana model 27 British made um in the post-war period there were products out there that were labeled um foreign made just to let you know that they didn’t come from anywhere you know uh from around here and possibly from some country where were at war with recently

And there were also things you could find that labeled Empire made which was in some cases a euphemism for Hong Kong but uh British made in this instance means it was made at the mil milboro Factory in in Scotland because in the postwar period Diana uh the Diana brand

Models tooling and everything was uh auctioned off in the postwar period um from Meer and GRL spacker the original uh producers of Diana guns and uh milbo purchas purchased that and made my Diana marked guns in Scotland until the 1980s this one uh has on its uh butt a

Stamping that suggests it was made in 1952 which is an early um early production for Middleboro products So within just the first few years so that’s kind of cool um but it isn’t a German uh made Diana and as such it doesn’t I believe it does not have the fancy see three

Ball bearing trigger there are ball bearings in it but they aren’t the type that uh release the C that pops open and the balls allow the uh the Piston to to escape um considered a very fancy trigger in its time this one is not that version but it is

A fancy type of trigger um when you [ __ ] the rifle it actually [ __ ] the trigger um we’ll get into that later on but it’s kind of interesting um as you saw in my introduction the the barrel is not in great condition uh I’ve been cleaning it and cleaning it and uh still getting

Crud out of it so um I can see the rifling now um probably should have looked at a little more closely when I bought it but uh I thought a but but then again every every air rifle I’ve ever come across whether the the boar has been dirty or not it’s always come

Shiny with a few passes of a of a swab in this case new I wouldn’t call it rust it’s not Rusty uh just uh uh dark gray Grime coming out of it s of caked into the the rifling I don’t know people shooting pellets out of it made

Of chalk or something stupid I I I don’t know hopefully there’s not too much abuse on the boore but um but there’s every reason to expect that it won’t be as accurate as I would like it to be but at least I can learn a lot from it I

Think it is an interesting gun just to look at it the uh the stock has that uh fairly weak kind of shape to it I’m not a big fan of this uh rounded uh rounded um uh pistol grip but uh but that was that was what they did at the time

Um the uh the trigger guard looks like it could be a stamping but it isn’t it’s actually rather nicely uh mil out of a thicker piece of metal um that’s a nice touch you don’t always see that the gun has a one piece cocking link it isn’t

Hinged so you do have this long slot in the stock which of course is always an invitation to see cracks appear in here but uh this one’s okay the stock itself um yeah it’s got scratches on marks on it some paint here and there like just

What air guns always collect paint I I don’t understand where does the paint come from but uh anyway the um the stock probably could could use some refinishing it uh looks a little bit tired so U but it’s a a nice little piece of uh Beach I guess but the gun’s

Got some nice nice touches to it some quality things you can see a locking screw on the uh on the main bolt here a locking screw on the cocking link the rear sight is just fairly straightforward adjustable for elevation only I looks like you could Dove tap it

Back and forth in the Dove tail here but you could also do that to the front side as well I think we’ll see how that kind of goes um no no place for a scope sad to say 1952 that wasn’t really on the on the radar um there isn’t a safety on it

Either there is a small adjustment here for the trigger looks like there’s some sort of locking screw for it or something I I appears to be missing so we’ll have to go over all that I’ve had it apart already just to take a peak inside it besides I had to take the

Barrel off anyway to try and give it a thorough cleaning I wanted to mount it in a in a vise and just keep pushing pushing swabs through it um try to bore snake I’ve tried various I actually went out and bought a 177 caliber boore brush because uh first time ever needed

Anything like that but uh yeah hopefully you know it’ll be a fun project to work on just kind of bring it back a little bit said 1952 that’s uh that’s a 70y old rifle now oh my gosh that’s hard to believe but but it is um so yeah we’ll

See how it goes the uh mechanism appeared to be pretty darn dry and looks like it hasn’t been properly lubricated in a long time if ever so but uh didn’t really see anything broken or missing except for that one little retaining screw on the trigger there so we’ll uh

We’ll have some fun with this and uh follow Along It’s Ch Okay so we have our model 27 all apart and we understand things a little bit better now um interesting setup for the trigger this is uh we can see a ball bearing in there two of them or something have to get a closer look at that um yeah the Fairly strong

Trigger spring here there is an adjustment there and there should be a locking screw in that that must go all the way up here and do something and this is an interesting design in that when you pull a trigger this pivots away from it and lets this piece go forward which let the

Piston get unlocked from it not entirely clear on how it all works just yet well that goes in there like that and that I don’t know it’s interesting um it isn’t the famous uh three ball bearing sear which uh which works I just grab this here the three ball bearing sear works

Very much like the collar lock on a on a on an air hose uh that you see with your compressor the uh the trigger allowed the thing to pop forward and allowed the ball bearings to pop out and allowed the the uh the Piston to go forward um

Clever design the ball bearings don’t actually they’re not in the trigger they’re just the release mechanism very clever but isn’t that isn’t what we’ve got here we’ve got a more conventional something holding the mechanism back oh this comes out the back okay yeah so here’s our sear surfaces but this all works together

With with the outer part that I put aside here I can’t see it um oh yeah right here so yeah this this thing rocks inside there and is meant to and there’s a spring there so yeah we’ll clean all that up and uh make sure it’s all working properly before I

Put it back together again it’s a little grubby the Piston uh and with the classic Diana locking surface on the back with the the stud uh this is a little bit bent looking and this isn’t quite round so and this is a separate piece that’s been

Hammered on the back and it’s a sheet metal assembly folded and cut piece crimped on the front piece crimped on the back uh I’m not sure how that compares to a pre-war Diana but this is clearly how milboro were doing it in the 1950s removed the uh the seal we’ got

Another one one of those vulcanite uh fiber washers in there uh and that backs up what I believe is leather this is uh it must be it must be leather it’s all kind of crumbling here there’s cracks in it uh I’ll be making a new one for that

I think and uh this just goes inside it to keep it shape and this also appears to be leather but yeah that’ll be okay so yeah it’s all pretty grubby but we’ll clean everything thoroughly and make new parts as necessary and see if we can

Uh see what’s going on here that is not round but maybe that’s what they had to do to get go down the uh the barrel or the uh the piston and we’ll clean out whatever’s in there and uh see what we got looks like a nice little

Project I gave all the interior parts uh thorough cleaning scrubbing all the um red residue of oil which pretty much has turned it looks like a a varnish butth it is just oil residue that’s just hardened on all the surfaces so give that a thorough cleaning and after all this I dunked all

The pieces of my uh ultrasonic bath and then uh which got rid of everything everything else that remained get it all ready for relubrication now to go about making a new piston seal first thing to do is to measure up the original pieces and try to figure out what size they’re supposed to

Be diameter is easy enough pretty much a a 1-in piston tube 25 mm that’s fairly standard then you have to decide what thickness of uh leather you’re going to use I chose this piece but uh if I was going to make another one I would use a

Slightly thinner piece for sure this one one then it being a little bit too thick end up having to uh shave it down just a little bit to get it in the gun so I already had this piece made but otherwise you take a drill bit and bore into a block of wood

To a good depth to make the mold for your your piston seal you soak your piece of leather in water for at least a day and you pick a a suitable candidate in this case end up being a 12 mm socket from an inexpensive socket set because

You you pound the leather which is fairly soft now into the recess and you let it dry out for at least a day let’s try to figure out just what depth I needed there I didn’t want it to be too deep so I stuffed a washer in there

Just to raise it up a little bit chose a nice sharp knife clamped it in a it first then chose a nice sharp knife to cut all around the edge of it at least partway through didn’t want to dull my knife on the uh on the steel of the socket used

To less fancy utility blade to cut the rest of the way through the leather or at least most the way through and the nice thing about leather is that it might look a little bit rough after you’ve made this piece but uh it will be conformed and molded to the interior of

The uh of the piston this piece here looks quite crisply edged but uh I’m sure it would have been when it was new and my new piece will look like that eventually as well I’ll clean up some of those rough edges a bit but it’ll be uh it’ll fit

Nicely and I chose a punch that would give me the right size hole for the retaining screw try to get it as close to the center of the thing as possible although again it doesn’t matter all that much then I dunked it in motor oil for another day just to get it fully

Lubricated so I have the Piston Parts all buffed up nicely here just a little bit of uh you know taken off some of the the uh the hard baked on Grime and smooth out some of the little rough pieces here and there but nothing nothing special but we now have our new

Piston seal um popped out of its uh wooden mold and uh yeah it’s a bit uh rounded than you you might think but the obviously the place to form that into exactly the shape it needs to be is uh well obviously stuffing it inside the Piston putting

Under spring pressure is going to form fit it hopefully perfectly to the uh to our needs and it’ll fit tightly so to put it back together again I need let’s see the screw this little intermediate piece which same age as the original seal but not crumbling nearly as badly so we’ll

We’ll reuse that for sure put these back in the camera Center here and I’m going to get some thread lock here we go going to use the blue stuff instead of the uh the red the red to remove it would require heat um yes I have no plans to remove

This thing anytime soon but uh but we do need it to be in there nice and tight and not come work itself loose so first things first this goes through there this goes inside there and then on top of this fiber washer which the gun originally had see

We’re losing focus a bit here so I can get a little closer no these don’t form as neat and tight a uh a fit as The Originals did but as I say squash it in there under pressure fire it a few times it’s going the leather is going to conform itself quite

Nicely to the to the confines of uh of the piston and I put this on there like that and we do need to screw that down nice and tight Perfect Fit okay there a bit of a Nick in the sidewall there I think that not sure how that came by but it

Should still be fine unlike a synthetic seal a leather seal is is fairly uh fairly tolerant of all sorts of little defects and things like that and it will as I said mold itself synthetic seals you get a small rip in them and they can just tear so uh

You have to be much more careful with them not you don’t want to be sloppy with anything going apply a bit of grease to this this is uh a uh Mal malib grease front and back of the Piston here probably should have put my plastic

Gloves on for this but there we go okay we have a bit of a a cup shape in here maybe more than we need I could have trimmed this back maybe another 16th of an inch a couple of millimeters but uh probably don’t need it it is going to

Press back a bit under pressure and that will squash it down to place um yeah it’s a good idea probably at some point to after having made a new seal like this sometime in the future take the gun apart and just make sure it is doing what it’s supposed to

Now this is going to go up in here and this is going to be a fairly tight fit being the first time these two pieces ever been together this could take a bit of squeezing again you don’t want to gouge the edges of your freshly made leather it’s getting it’ll get in there

But it’s not going to be easy also not very easy to do this with the camera in the way no I’m going to have to fiddle with this a bit probably have to do this off camera get to get enough room on the bench to do that anyway we’ll we’ll squeeze it in

There well I’m almost done cleaning and polishing all the parts I still got little ways to go here and there on some of them but uh while I’ve still got it all apart I thought I’d be kind of fun to go over one of the things that makes

This rifle a little uh special a little unique and certainly a little more unusual uh compared to some of the things that I usually work on this is the the piston and trigger mechanism from the from the rear of the gun as you can see this is the the main piston

Spring which uh and its spring guide which goes up inside the main piston here and is compressed I’ll take this out of the way since we know what it does and the spring of course is held back by the spring guide and can’t go past here this is the top of the guide

And this is the pin that goes all the way through and anchors this sleeve inside the main the main piston tube um so what is all going on here this interesting cone shaped surface on the on the back of the Piston pushes through that and comes into here this rides inside this sleeve

Goes in from the back and oddly enough this thing wobbles up and down a good bit got that pin pin in there properly but yeah it it doesn’t fit it is it isn’t a tight fit it actually wobbles a bit and this spring sits in there like that up against the Piston

Tube and keeps it pressed down keeps downward pressure on it when this piston comes in it locks against that piece this this this uh this side uh this surface right here is biased against the inside of this which I can show you easy enough it’s

Better to do that now with that out of the way now that we know what it does this rocks down this little surface right there is the actual latch that holds the Piston from going forward and it is pressed down again by that little kept down by that little

Spring um I do wonder how safe it is I wonder if you would to whack the gun hard enough would it would this part vibrate enough to unlatch and let the gun fire um I might actually try that [ __ ] it and then uh whack it with a

Mallet and see what happens but how does it actually fire because this is the trigger right here and it’s pinned to this part right there and it has this wonderfully tough little ball bearing on it and this other piece which is adjustable for height you

Can move it up and down um I think it should be somewhere around about here for maximum effect but it can go up and down quite a bit a locking screw goes in from the front which is missing I’ll have to find something for that but this

Piece attaches to this is pinned to this right there and it rocks back and forth and when if you can see the ball bearing one ball bearing in there is makes contact and then then as a trigger comes forward then it it Teeter totters onto onto that next pin and really pulls it

And this is the sear right there well that has nothing to do with our wonderful little uh latch up here it doesn’t come anywhere near it what this does is this piece right here when you when you um [ __ ] the gun and push that all the way through like that this piece

Which is riding in from the back is pushed all the way back to where this surface right there latches on the trigger sear very neat and what happens then is this rather Strong Spring is pushing against that that that inner piece and can’t let it go forward until the

Trigger lets it go and you just see it just snaps far just just goes that far forward and what happens there is this this wedge shaped piece smacks forward and forces these two apart essentially pushes this up out of the way and lets the Piston go forward this is

Effectively a hammer and we are releasing a little small Hammer powered by this so the trigger only has to worry about the spring pressure here and the great massive spring pressure of the Piston spring does not bind on the trigger mechanism at all so very clever system and I believe this is

Probably what uh Diana enthusiasts call the falling block trigger the pre-war design because this gun made by milbo in Scotland under the Diana name um I don’t believe they would have designed an all new trigger in the 1950s for 1952 when this gun was made so I’m guessing this

Is the pre-war design brought back to life under Scottish manufactur so yeah why was this replaced by the famous ball bearing trigger where you’ve got three ball bearings that let let the uh let the Piston go um probably that was actually easier to manufacture you got a fair number of

Little shapes here with some fairly complicated Milling procedures to make them exactly right so it might be that this was just too complicated a thing to make and after having taken the gun up part initially and inspected it and then put it back together again I can tell

You this was a bear to put back in uh I imagine there must be some sort of jig that the factory would used to compress everything together and then allow you cuz you have to push this spring past this pin when you’re putting it through that’s not easy um there must have been

Some special special rig that would have done it allowed it to to compress and yet enough room to get the pin pin past it I’m going to have to see what I can do to make it a little a little bit easier than what I did last time but uh

A very clever and ingenious trigger mechanism and uh when it’s all clean and lubricated we’ll have to evaluate how it does because it was a bit rough when I when I first tried it all the parts are pretty gunked up and I think this was not at its best

Adjustment so yeah very cool and uh we’ll get it all back together again I decided to remove the finish off the stock mainly by scraping it avoided using uh paint stripper for as much as I could but uh one thing that surprised me was how you don’t only

Notice it at first but the the tone of the original varnish was had a certain greenish Hue to it that when you scraped it clear it was like oh wow the wood was a lot nicer and uh warmer yellow than it first appeared that varnish did uh did remind

Me just a little bit too much of old school desks from elementary school so I was quite happy to get rid of it so after much uh poking prodding and massaging I’ve got my uh piston seal on the front of the Piston neatly tucked up inside there and I’m all ready to begin

Assembly of this uh fairly simple mechanism here uh the spring which I uh fixed the end on it this one here because it was driving me crazy sticking up in the air bit I’m going to lubricate it with lithium grease in this instance instead of the uh the red and tacky

Stuff because I don’t think it needs the extra dampening of that uh of the sticky stuff in this instance so I’ll slide that in halfway and do the rest of it the tricky part is going to be trying to get the trigger mechanism in because I haven’t quite figured out

The easiest way to do that or how they did it at the factory except obviously they must have had some sort of a jig to compress all the Springs at once and uh get the bits in there um yeah that goes in there like so and this goes in behind it and this

Has a little hole in the top for this little spring here H which means this has to go inside that way and uh yeah grease that as well in this instance I’m going to use Molly grease I prefer grease on slow moving surfaces faster moving things usually require

Oil and the nice thing about grease is it doesn’t migrate out of the way so this has to go in there like so and this pin goes through there like that and through the through the piston tube and I get a little tiny sh sliver of leather

There so that goes in like that but this has to go in first again some more white lithium on here inside of the spring and this part I notice is a little bit this end of the tube is not quite perfect But well I’ve got all the trigger bits back in and the Piston is in place little bit easier than I did it last time just trying to figure out how the factory would have held that spring past the pin while they got it through so it’s in

There now I should be able to pull this one out because of course I need that to attach the Trier guard it should come out again it’s pretty stiff but it was a pretty stiff screw to start with yeah that just goes straight through that threaded hole there and there’s a recess

That hold holds just a a pocket that holds that in place there so you can see the two-stage trigger mechanism here they get first stage and second stage at least I think that’s what’s supposed to be going on we’ll see how that works out um the adjustment for it right there as

I said yeah okay not much more to do now and just put the rest of the pieces back on and turn it into a finished rifle okay so we’re going to try the newly refurbished Diana across the chronograph let’s see how we can do with

That going to shoot uh at least I get 10 shots of RWS super doome which are an 8.3 grain pallet so slightly on the heavier side there we go that should do it to okay 275 that’s pretty much half what I just saw on the previous shot 480 483 for

82 479 wow this really consistent 477 Three three More 51 57 three six so now that I know the gun has good power I shot it at a Target at some 27 yards and I discovered the pellets that it like the best were the uh these jsb exact Express the 7.87 grain ones because I ended up with a 22 mm Group

Which I’m pretty content with given that it’s uh iron sights at a fairly long distance on the uh negative side the uh the group is a bit High about some 4 in above my point of Aim so perhaps I can add a bead to the front s side or

Something because uh the rear site was all the way down so something to consider for future if at some point during this video you were wondering where have I seen this gun before or something like it well if you think back to episode five which uh is probably my most

Watched video of all the Shanghai 61 an inexpensive rifle from China uh made probably in the 1980s and it seems to Bear more than a striking resemblance to this Diana 27 I’ve had people speculate that the that the Shanghai 61 was based on a BSA based

On a slavia based on other things but when you look at them side by side it’s hard not to see some something of a family resemblance here the the Shanghai overall is a bit shorter uh the barrel is only 39 CM versus 43 on the uh on the

On the Diana the Diana also has a rather long longer uh piston tube than than the than the uh than the Shanghai but they’re finished off in a lot the same way you have this very Square front end on it main pivot screw with a locking screw the uh the sights are ridiculously

Similar that little ladder that you pull back and forth on there um clearly clearly I think the Chinese Factory had one of these on hand when they were putting this together the single Groove and the forearm the uh single piece cocking uh cocking linkage this is a solid casting

That has no jiggling or vibration whatsoever this one is a hollow uh stamping and uh it wriggles around quite a bit in there a much less expensive gun and of course they did not copy the rather overly intricate and clever trigger mechanism in here um this just

Has a very direct sear but that said it’s not terrible uh this this actually shoots pretty well um for its shot cycle I have struggles with accuracy with it but uh this one definitely definitely a much more refined gun a lot smoother in uh cocking and closing it yeah it’s

Definitely definitely uh draws us inspiration from this one I think so there’s your answer all those who wondered where the Chinese got their uh inspiration from so some final thoughts on the Diana model 27 at least as far as this uh British made version goes I do start to really understand why

People consider the 27 a classic air rifle as I said earlier on it seems to be the right weight the right size to be a gun that could be shot happily by a youth who’s learning some Marksmanship but also it can be a very good uh air gun for a grownup as well

The quality is there uh the accuracy is there even with this example with a a very rough Barrel it still seems to shoot better than a lot of other things I have um and it just the overall quality the way that it locks up the way everything is you know tight doesn’t

Rattle it is excellent yeah there’s a few things I could uh improve on it such as the uh the site picture for instance but overall thanks for watching canak care will be returning consider subscribing