Slavia 620 Teardown and (hopefully) Rebuild

[rr_shooter]

In helping my family clean out my mother’s house in preparation for its sale, I came across one of my favorite childhood possessions tucked away in one of the bedroom closets – a CZ Slavia 620 .177 break-barrel rifle. I received this as a Christmas gift when I was about 10 years old, as best as I recall.  Throughout the next few years of my life, it was my nearly constant companion on weekends as I prowled the woods near our home, target shooting, plinking, and doing my best to rid the region of English sparrows and European starlings.
As I grew, my interests changed to bigger air guns and powder burners.  The Slavia, as happens to many things in our lives, was pushed aside to make room.  Maybe it’s an attempt to regain lost youth, but I want to give the Slavia a new lease on life.

Armed with the knowledge base found here, I’m determined to make amends for some of my acts of “maintenance” in the past (I had been known on occasion to give a squirt or two of WD-40 down the transfer port, just to make sure everything was “well lubed”.  Hey! This was nearly 40 years ago – how was I to know how detrimental this could be???)http://www.gatewaytoairguns.com/airguns/images/emoticons/frown.gif

Disassembling the gun was pretty straightforward. There seemed to still be an acceptable amount of grease in the important areas.  No signs of galling, and minimal wear of metal parts throughout the action. Once I got it apart, I was struck by the dichotomy of the design of the gun.  Some elements show a fair level of sophistication for that time period - the end cap is threaded, just as in many Weihrauch models, and the piston seal is synthetic.  On the other hand, other elements display a crude, if not simplistic approach - the spring guide is made of stamped metal rolled into a tube.  And the trigger, which features a nicely serrated blade, utilizes a direct engagement with the piston.  Not the best design for feel and it provides no means of adjustment, but I guess it’s acceptable for a gun of this power.  I’ve included a few photos to show the trigger engagement arrangement and the piston.  A B3-1 piston is also in one of the pictures for comparative purposes.

As I recall, publications of that era showed a typical velocity for this model to be a pedestrian 560 fps.  Certainly not notable in today’s market where 1,000 fps velocities are commonplace, but at a time when only three European break-barreled rifles broke the 700 fps barrier, it was certainly serviceable.

So far, I’ve just performed the basics – de-burring the slots on the piston and compression tube, knocking off sharp edges on the piston body, and polishing the trigger sear and corresponding face on the piston.  There’s no tophat on this rifle; I’ll probably add some nylon washers in the piston to minimize spring torque.  I’ve been looking on-line for parts resources for this model, and frankly have not had much luck.  I’m even having difficulty locating dealers for this brand.  I’ve seen discussions on this forum about more recent Slavia models, so I know they’re out there.  In particular, I’d like to find replacements for the piston and breech seals.  Perhaps other Slavia owners would have suggestions in this matter.  

The spring, not surprisingly after all this use, has a significant cant.  It has 36 coils, and my caliper measurements indicate an inside O.D. of 0.506 in. and a spring diameter of 0.112 in.  I haven’t investigated Macarri’s site yet, but I’m hoping I can find a replacement there.  Maybe even drop in a slightly hotter spring to get it over 600 fps.  I’ve seen a suggestion on another forum of using a BSA Meteor spring as a replacement – anyone tried that one?

Any thoughts or words of wisdom from other forum members would be welcomed and much appreciated.
 :0  :0  :0

[rr_shooter]

The pictures I meant to post...

[hyounker]

Paul,

I remember a friend when I was young (just a few decades ago!) had inherited what I believe was a Slavia.  It didn't even have a dovetail to mount a little scope on it.

Nonetheless, your description of the spring guide reminded me of what I found in my B3 recently:

http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=13016&mid=106164#M106164

I am in the process of making a new spring guide for the B3, so that's an option (for some).  As a rookie at this, I wonder if you could replace that piston seal with a leather one.  I keep reading how much better the leather ones are over the synthetic seals for compensating for the imperfections in these cheaper guns.  I don't know if this is even possible, but maybe this post will get others to clear things up about it.

There's a link in the library detailing how to make custom leather seals (You'll have to customize your setup):

http://www.gatewaytoairguns.com/library/Making%20Leather%20Seals.htm

And Bob has posted some instructions for making a synthetic seal here:

http://www.gatewaytoairguns.com/library/Seal%20Fabrication.htm

Keep us posted on your progress and techniques.  

[airgunandy]

I've got an old Slavia 618 that had belonged to a an uncle of mine. Nice little gun and very accurate.
Mine has a sheet metal trigger like a B3. Haven't had it apart. I dribbled a little Bardahl's No-Smoke in the cocking slot a few years ago (didn't know any better then) to lube the spring and smeared a little on the breach leather seal. Shoots smooth and actually doesn't diesel. There's no smoke!

One of these days I need to tear the bugger down and lube it the right way. I'll keep an eye on this thread to see what happens.

[rr_shooter]

Henry -

Thanks for the response. We may indeed be talking about the same rifle.  My 620 does not have any dovetail grooves on the receiver.

I'm hoping to stay away from converting to a leather seal because, without access to a lathe, I'd be concerned about drilling and tapping a centered hole in the piston.  I'll keep looking, and will post any updates.

[rr_shooter]

Andy -

I agree with you on the accuracy - I remember I could hit pretty much anything I wanted to out to 20 yards or so with the iron sights - but my eyes were a lot younger then!  If I come up with the parts to update it, I'll post the progress here.

[airgunandy]

My 618 has grooves at the rear of the body tube to mount a diopter sight (I think that's what it's for). They are about the right width but very short for a scope. I have scoped it using one one scope ring, but it looked so ridiculous I took it off and never tried to shoot it that way.

[togojeff]

rr_shooter - 1/22/2009  8:48 AM

  On the other hand, other elements display a crude, if not simplistic approach - the spring guide is made of stamped metal rolled into a tube.  

I bought one new last year and the spring guide hasn't changed any since they made yours. :emoticon: