Yesterday I put a new spring and leather seal in my old (1970) 25 (not a "D").
It was amazing to see the old spring and seal still in good shape.

With the old spring and seal, the gun managed 519 fps with R10 heavy (4.50mm) (4.91 fpe) (the brand and type of pellet it liked best)

I had high hopes for the new Maccari R7 spring...

Just after installing the spring and seal, it did some 330 fps
R10 is now doing (struggling) 470 fps
So things seem to be improving after just +/- 100 shots

Just a question: how much can I expect after the tight fitting seal is broken in ? 600 fps would be ideal ...

Thanks !

Joris

I did it over the summer and am getting 575. Originally, I used a lot of spring tar which slowed it down. I broke it down again, cleaned off the tar and re-lubed with just moly.

If it's a new seal, it will take at least 1000 shots to get it sized right.

Good luck

Think Straight, Talk Straight

Thanks, Marcelo,

I will do likewise and clear off the heavy tar and use some moly sparingly.
Maybe I also used too much clear tar on the piston itself.

It's always a struggle to open and close a gun since my decompressor works very slow. I need to make me a better/faster one.

Kind regards !

Joris

My D25 (.177 cal.) had a Maccari (Beeman R7) and heavy tar change over, including a new pistol and leather seal, new trigger, the lot, two months ago. After nearly 1500 pellets it started to settle (I can tell by the lack of excessive noise, as it is very quietr now) and is now shooting better than ever (and me). It is remarkable how it (now) digests everything accurately: H&N Baracudas, Crosman Premiers 10.5 Die#2, H&N Silver Points, Copperheads 7.9 and every pellet made under the Sun. Enjoy your D25, Joris.

Hello Nikos,
Can you tell me the velocities you are getting out of it ?
Is it Ok to shoot such heavy pellets in a small springer ?
I would really like it to do some 575 f/s with 8,2grain, like Marcelo's gun.
It would make me sleep better.
532 like Whiteleather seems rather slow...

Kind regards,

Joris

Joris

...my 25D with R-7 spring and synthetic seal using Meisterkugeln in .177.

Kris in NY

Hello,
Thanks for the reply.
Is it possible to get a synthetic conversion seal "over the counter" ?
I once asked Maccari and he said it was possible, provided some modifications are carried out.
But Hector advised against it, saying the leather one would probably last forever.

Joris

btw: I read your review on the 48 .25 again, and it really wetted my appetite for this gun, though I'm also considering the Weihrauch 77K in .25 as energy is not that important (I may even detune it to 12fpe in order to take it to England once in a while) and as long as it shoots a .25 as fast as my 24 shoots a .22, I can very well live with it.

Joris

Joris,

Following a mainspring change-over, the usual procedure for me re the D25 is to shoot the heaviest pellets available until dieseling disappears. Afterwards (some 50 pellets weighing 11 grains like the H&N Silver Points), the D25 can be fed the lighter ones.

Then, every now and then I pick up the CP 10.5 Die#2 to see what the D25 is capable of performing in the precision/accuracy department, as the Crosman Premier Die#2 are the most consistent airgun pellets I have ever seen and I am down to my last 1,200-capacity box, so I use the w/frugality.

There is nothing stopping me from alternating between light (Crosman Copperhead Domed 7.9 grains) and heavy (H&N Silver Points @ 11.0 grains or H&N Baracuda @ 10.1 grains).

As I don't have a chrono, I use a bog-standard method of measuring my air rifle's power: I use glycerine soap bars. I shoot two or three pellets into each soap bar (which measures 6-inches X 2-inches. Both the size of the channel and the depth, produced by each fired pellet, give me an instant indication of the power produced.

So before I changed springs in the D25 I shot the soap bars with all of the above-mentioned pellets and some Dynamic Sn1, Dominator, Match and PPP (bought from Pax Guns in North London, UK). The R7 (Maccari) spring fared best overall. All pellets stopped at the exact same place, in depth. Deeper than the RWS-factory D25 spring ever managed by an inch (or a bit more). The Crosman Premiers (Die #2) went deeper -- penetrated the glycerine soap -- than any other .177 pellet tested!

I recommend the glycerine soap for testing, as it helps me to monitor the fatigue of the airgun's performance at-a-glance, and I have a visual record of how the various pellets perform, as they show clearly like frozen missiles stopped in mid-flight! Waaay Coool!

Hope this helps.

The leather will last for a very, VERY long time. When mine finally went bad (after 20 years) the fella I had do the work simply had synthetic seals on hand.

Glad you liked the M45 in .25 review. It is a very solid rifle, as are all the Dianas. If you like .25 but don't need all the power, consider an Exocet. I see .25 cals available every now and then. I am told they are slower than the Diana 48 or the Patriot, but at 25 yards getting hit with 21 grains of lead will hurt no matter how fast it is going. The Exocet has a good reputation for accuracy as well.

For plinking, nothing makes targets ring like .25 cal.

Kris in NY

Today I ungreased the spring and piston and shot again. No improvement, so it must indeed be the new spring.

Pfff ! So now I must shoot (already 500 done) still some 1000 pellets before the Diana reaches the 6 fp barrier...

Joris

It won't be the spring.I've done plenty of 25's with that spring and if they don't do a strong 600FPS with Silver Bear 177's,there is something wrong.
Usual problems relate to poor lubrication.

Sorry,
I mistook. Instead of "spring" I meant it must have been the very tight fitting new leather seal that causes the low velocities.

Joris

Where did the seal come from?
Maybe you just need to size it...
What lubes are you using and where?

Hello Lewis,

Thanks for replying.
I bought two new seals via a Dutch internet store, specialized in airguns.
www.luchtbukswinkel.nl
I got one for a 25 and another for a 27. In fact, they are identical.
See Chambers www.chambersgunmakers.co.uk part: 301246

I use the following lubricants:
Maccari heavy tar: spring
Maccari moly: pivot parts and contact points and slightly on the outside of the piston
Maccari clear grease: ... not really used.

But as I said, I removed the heavy tar from the spring and only left some small amount of moly, but it doesn't change a thing.

But when one pushes the piston home, one feels the tight fitting of the seal.

Thanks for your reply,

I got two Maccari springs: R7 (for25) and Global Tarantula Small XL Spring (27)
When compared to new "original" Diana springs: 300294 (25) and 300374 (27) they are identical: as many coils, same lenght. One only sees the difference by looking at the finish. The Maccaris are better finished.



Joris

I ususally soak my seals in silicone oil before installing a new or reconditioned leather seal. Then I dry them with a rag before installing.

K

But what did you lubricate the seal with? I use a drop or two of SM50 then a wipe of JM Moly on the side then install..I keep it juicy with a drop of SM50 every 500 shots or so.
Not much tar is needed!
Those springs are perfect for the 25 and 27 and what I use.

...but not too much.
... was this a bad thing to do, Lewis ?

Joris

Clear Tar is not meant for that application.I use it on sliding compression cylinders eg HW97/TX200,cocking lever pivots,barrel detents etc.Great product for those places but not where you put it!
Use SM50 (Randy Bimrose) and some JM Moly on the sides.