I have a model 27 from 1971 and can get a nice 25 (not a "D") of about the same age.
As these guns already have quite some age, I would like to replace the springs and give them a "tune". Not in order to enhance power (these guns are super plinkers, not hunters) but to make them as smooth and good as possible.
Does anyone have any experience with Maccari springs in such guns ? I wonder if ZVP has a Maccari-tuned 25 ?
Besides the spring, are there any other parts that may/can be ordered ?
Chambers in England provides most parts for almost any Diana. Anyone any experience ? If I am right, Chambers sells the same spring for a 26 as for a 27. Does this mean that the 27 gets more powerful, or that the 26 gets less power ?
But I suppose the Maccari R7 spring should be of higher quality.
I'm not sure about the 27, but I installed a JM R7 spring (HW30, same thing)in my 25 with no problem.
The piston has a leather seal. You could send the piston off to Paul Watts and have him machine the end to fit a JM Apex seal. I didn't find that necessary, the leather seals are almost indestructible
My D25 was old and decrepid but I restored it and added a Weaver TO9 mount rail, which permits the use of Tip-Off rings or Weaver cross-slot ones.
To attach the TO9:
1) I aimed with the open sights at a point on a wall at 10 yards/meters.
2) Fixed the rifle in position on a rack.
3) I attached a small 4x15 Anschutz/Savage scope to the TO9 using Tip Off rings.
4) I aligned the scope's crosshair to the aiming point on the wall.
5) Cut two or three strips of masking tape to have handy.
6) Using some Liquid Steel two-part epoxy on the underside of the TO9 and a bit just ahead of the Diana Godess MODEL 25 inscription, I placed everything on the receiver so as the crosshairs coinside with the dot on the wall and secured everything with the masking tape. Wipe the excess glue away and wait for it to dry completely before touching (@ comfortable room temperature).
24 hours later, presto!, Weaver/dovetail mount rail on the D25! with scope ready to fire. Only minor adjustments were necessary to get all shots to touch at 10 meters (33 yards).
The Liquid Steel 2-part epoxy I recommend should be removable with a blow torch or something similar, so as to return the rifle to its original state, in the future. I tested the epoxy on some blue Weaver rings to see if it would marr the blueing and find out how to remove the glue, in the first place with a blow torch (the sort that makes Creme Caramelle). So, I found a German epoxy that doesn't harm the blueing, leaving no marks and the like on the precious Diana.
Although my Winchester 425 has a scope rail, the time you took to post your mounting information is appreciated. I'm sure that some time in the future I will need to use this technique for mounting a rail. Great info! Old eyes appreciate your help.
Thanks
Chris
A tuner installed an R-7 spring and new synthetic seal in my all original .177 25D. No problems and mean velocity of 10-shot strings is currently:
406 FPS w/Crosman Premier Heavy
445 FPS w/RWS Super Mag
532 FPS w/RWS Meisterkugeln
Standard deviations are pretty high considering the tuning, but the rifle is spot on at 35 yards with a peep rear and a standard RWS adjustable front sight.
The first few were over 550 but that was probably a little dieseling, after 20 shots, it seems to have settled at 490.
One of the great things about JM springs is that the cocking effort is actually lower than the original Diana spring, yet, the shot cycle is faster. No twang at all, just a little, quick thunk.
OMG ! Not even 500fps. My 24 .22(!) does 522 with RWS hobbies and a standard spring. The velocities you are getting are those of a target pistol.
I suppose the velocity will even be less in a 27 since it has a longer tube and a less comprimed spring ??
Do you happen to know someone in Europe who customises airguns as sending a gun to the US (and getting it back) is nearly impossible.
If it is in Belgium (where I live), Holland, England or Germany (or even France) I can go there by car. (It's always a struggle to get my guns in my very small car but the car seems custom build for the transport of up to three rifles with expert organisation)
I didn't see it was a .22 model 25. Velocity is quite decent.
The velocities for the .177, however, are slow and the same level - or less - than a target pistol that will do around 480 - 510 fps with RWS R10 "lights". Is it possible the gunsmith shortened the spring ??
I will not replace the leather seal, just installing a new one. Do you think it is advisable to order the Maccari heavy tar for the spring ? Most FT shooters with Weihrauch 97 and Air Arms 200HCs models seem to swear by it.
The JM-supplied mainspring (Beeman R7-type), that I fitted my restored D25 is by far the most consistent, after 20 settling shots. From shot #21 onwards, the point of impact @ 35+ meters just stays the same, no matter what. It is this special feature that I like. RWS-supplied ones are more powerful and inconsistent, in the long run.
As I have Venom's Moly for the odd mainspring change, I prefer JM's heavy (black) tar. The only downside I have experienced is that if the rifle stays under hot sun for more than a couple of hours, an occasional flyer will occur, mainly due to sudden dieseling probably caused by minute amount of melted tar finding its way in front of the piston seal. Nothing serious, as with that shot the minute amount disappers and all subsequent shots are back on the money.
I used a shortened XS-B3 spring in my .22 cal. Winchester 425. The wire diameter was slightly larger so it was just a snug fit on a polished spring guide. I do not use tar on these lower powered models. I have had very good luck using open gear lube applied the same a J.M. tar. Soaked the leather seal in RWS chamber lube (silicone I suspect) for at least 24 hrs. Velocity with .22 Hobbies is 420 fps. and going up as the seal seats. Fun to shoot and very smooth to cock with not twang. Crosman wadcutters are running about 400 fps. The down side to these guns is that they are so much fun to shoot that I end up with way more empty pellet tins than I know what to do with.
Have fun!
Chris
I have three versions of this lovely Middleweight family.
The first, a badly mistreated .22 Hy Score 801 (that actually created the concept for this Forum!).
It was well cleaned, had the Mainseal saturated with Silicone oil (3 day saturation/week longing drain),gets a few drops of "WebOil" every now and then...It had a badlly bent BBL, and I spent about a week (total) playing with straightening it. Compression and Mainspring were good, so later on, a little Maccari Heavy grease was rubbed thru the cocking slot for smoothness. Even with the bent barrel accuracy was great, but hit low and now is "spot on" @ 30 yds with RWS Hobbys. Open sights (has an odd 1900 US patent, replacement, rear sight that came with it. A hard .22 cal hitter, in spite of it's Stock innards!
The chipped, dented, stock refinished with a light Pecan finish. Bluing still sucks (someday...?) It feels like an old bar of soap and is one of my absolute favorite plinkers!
Second. I have a second hand, .177 Geco 25D. The VERY weak stock mainspring was exchanged for a Maccari R-7 unit, lubed with various oils and finished with a light coat of Maccari "Heavy" grease. It has all it's Stock seals still
I consulted with Lewis Reinhold, of Beemans Au. and Jim Macarri to have their expert opnions on replacing it's origonal Low Velocity, "factory" Diana-5 Pistol Mainspring, with my propsed approx. 600fps neighborhood wants... Didn't build customguides or spacers but looking back now, I should have. The firing cycle is now quick, a bit harsher now, and velocitys are very consistant and in the mid 600's on average. Accuracy remained great, just farther, flatter trajectorys downrange now! At 10m it's a tackdriver, at 30 yards, sub-1" groups are easy over a bench!
I scoped this sweetie with a Daisy Powerline Variable (a really neat and inexpensive scope!), mounted in low-profile Weaver rings. Call it my "Old Man's Garden Gun".
Third. I have a pristine late 70's, .177 Diana 25. Cleaned and smoothed by it's second owner. (JM "Heavy" Tar is on it's mainspring of course!) A smooth, powerfull, and accurate preformer! Factory open sights. A delight to shoot!
Don't have a "real" JM tuned Middleweight, but am SURE a well tuned Model 25/7 would be fantastic!
There IS a reason this Family of Middleweight Diana's is so popular, they are very good preforming little rifles that beg to be shot and genuinelly deliver MORE than expected!
Yesterday I bought the mint 25 .177 (not a "D" however, but easier to strip the trigger ) It is from 06.1970. It's condition is practically as new, but I always seem to be lucky with finding old but pristine guns (also my 27 and a .32 Browning 1910 pistol of my birth year: 1964) Happy me.
As with my 27 it clearly, and by far, prefers RWS R10 8,2 grain pellets and averaged at 520fps or 4.93fpe. So I suppose this little 25 has no spring wear after 35 years. But then it also has no wear on the stock, nor on the blueing.
Still I'll order a Maccari R7 spring and a new seal to revitalize it as well as possible and to make it happy. (I'll give my 27 (RWS R10 8,2 grain 589fps, 6.32fpe) the same treatment.
If the 25 will do something like 600fps it can do double duty as a "pest-gun".
I got the airgun-bug only last august and I have never taken apart an airgun. So today I took apart my 1980 vintage Feinwerkbau 65 in order to fit a new spring. The reasoning being: if I can work on such a complex gun, the Dianas will pose no problem...
In november I might go to england to shoot pests on an estate (rats, squirrels, rabbits, pigeons) and I would like to take my 25 and 27 along with my 34 (.22) and the Weihrauch 97K (.177). I suppose a 27 will kill with a good shot at 20 yards as I killed scores of doves in my teens with an airgun of similar power.
but the car seems custom build for the transport of up to three rifles with expert organisation)