Anyone tried the two sping tuning kit for the 631?

[pgritty]

https://www.ebay.com/itm/ABSOLUTE-TUNING-SLAVIA-631-TWO-SPRINGS-FAC-300M-S-Free-shipping-AIR-RIFLES/173818862746?hash=item2878695c9a:g:rSgAAOSw5XJcerYo
Was wondering if this was a worthwhile upgrade. I just purchased a Slavia 631 Model 77 Lux on ebay and it needs a piston seal.
Pat

[lefteyeshot]

I bought two. One for a B3 and one for a Stryker gas ram. The one for the B3 was to big to slide into the piston. Haven't tried the other yet. I was thinking maybe it would work in an old Crosman Storm. About the same as a Optimus.

I was thinking also about using one in an old B2 then remembered the B2 has a center rod piston that wouldn't fit in the small inside spring and with a center rod piston you can't use the spring guide comes with the kit.

I have a 631 but have never tore it down. It shoots great as is. It's become my 25 yard paint ball buster. If memory serves when I've seen a exploded picture of the 631 parts it has a center rod piston.

Guess I need to get the spring compressor out and start experimenting. Might have to clip some coils.

[pgritty]

Tim, here is a video of a 631 being disassembled.


Looks like these rifles are very easy to work on with the original springs.

After doing more research I found this thread. https://www.gatewaytoairguns.org/GTA/index.php?topic=137639.0
That person did not have anything good to say about the 2 spring kit. That was the only review of the 2 spring kit that I could find.

I will take mine down and see what kind of shape it is in, then decide on whether it needs a piston seal or new spring.
Pat

[larspawn]

Wow no preload at all!  Never had mine apart because it shoots so well as is.  The spring kit kinda makes me think, "why turn a sweet little 631 into a 634?  Just buy a 634."

[pgritty]

Wow no preload at all!  Never had mine apart because it shoots so well as is.  The spring kit kinda makes me think, "why turn a sweet little 631 into a 634?  Just buy a 634."

If you could find a 634.lol
Not super interested in a lot more power, just think the one I have is especially weak. Will find out more when I take it down. Maybe a bad piston seal or weak spring.
Pat

[larspawn]

Wow no preload at all!  Never had mine apart because it shoots so well as is.  The spring kit kinda makes me think, "why turn a sweet little 631 into a 634?  Just buy a 634."

If you could find a 634.lol
Not super interested in a lot more power, just think the one I have is especially weak. Will find out more when I take it down. Maybe a bad piston seal or weak spring.
Pat

I'm going to thin my herd in the next year so look out for a package deal on all my Slavias. LOL. Retiring and need to travel light in the next year or so.  Have been contemplating selling off my 618, 620, 631, 634 and pistols.  But I love my 631 because it is so accurate and easy to shoot.  Its big brother 634 is the same only about 200 fps more umph!  lol. Yeah don't see any of them for sale anymore.  I'm guessing they are gathering dust in old dudes' safes.  It is actually impressive the power of the 634 when you consider how docile they shoot. 

[pgritty]

Took the 631 apart this afternoon and found the piston seal is super tight. Worked on the seal with some sandpaper but it is still very tight. Put it back together and with some r-10 pellets was hitting my 1" spinner 8 out of 10 times sitting, shooting offhand at 10 meters. Nice rifle.
I will look into getting a new seal and see how it goes.

Larspawn, keep me in mind if you decide to move the 634.
Pat

[lefteyeshot]

I've got a 634 and yes it has more power than my 631 but not as accurate. When you cock the 631 there is a little free travel before you're against the spring. With the 634 as soon as you start to cock you're against the spring. Both are keepers. I think of the 631 as a poor man's 124.

[lefteyeshot]

Pat, I saw that review back then. Seemed to me the guy disliked the people more than the kit. Maybe he was right.

I watched the video and saw the 631 has a center shaft piston so I don't think the  kit would work in the 631.

[pgritty]

Thanks for the information Tim. I agree about the tone of the review being kind of personal to the seller more than the product being sold.

The spring might work as the original center latch passes all the way through the spring that is in it now.

All that said I took the rifle apart and worked on the seal again. When I first put it back together I had to shove the piston back into the tube with quite a bit of force. This time, after sanding the seal down, it was much easier to install the piston. Originally at 10 meters it hit my one inch spinner with a slight dink which barely rocked the spinner. I'm guessing somewhere around 300 fps or less. Now it spins the spinner 2 to 3 times when hit. I'm guessing closer to 500 fps. Much improved.

I really like the feel and accuracy of this rifle offhand. I think that this one will be around a while.

Pat

[lefteyeshot]

The inside spring is too small for the center shaft to pass through.

FYI: Just looking at some old notes. The 631 shot RWS hobbies 7grs around 625 fps and the 7.33 gas domed JSB'around 610 fps. The notes show it likes Meisterkugeln and R-10 Match for accuracy.

The 634 shot Meisters about 780 and Super mags 680fps.

[bhh]

My son bought the two spring kit a couple years ago. I can't remember all the details, but it was not good. I seem to think it made the shot cycle a lot harsher and didn't give an improvement in velocity. Also, rear spring "guide" didn't fit right. He ended up getting a refund.

[pgritty]

My son bought the two spring kit a couple years ago. I can't remember all the details, but it was not good. I seem to think it made the shot cycle a lot harsher and didn't give an improvement in velocity. Also, rear spring "guide" didn't fit right. He ended up getting a refund.

Good to know, thanks for the information.
Pat

[lefteyeshot]

My son bought the two spring kit a couple years ago. I can't remember all the details, but it was not good. I seem to think it made the shot cycle a lot harsher and didn't give an improvement in velocity. Also, rear spring "guide" didn't fit right. He ended up getting a refund.

Do you remember what gun he put the kit in?

[bhh]

Do you remember what gun he put the kit in?

Yep.   Ooops.    I see the title was asking about the kit for a 631.  His is a 634. So his experience may not apply to the 631. The kit may be absolutely wonderful for a 631.  Sorry about that.

But if the rear spring "guide" fits a 631 like his fit a 634 I don't think you'll be happy. I guess there is only one way to find out. 

[lefteyeshot]

Do you remember what gun he put the kit in?

Yep.   Ooops.    I see the title was asking about the kit for a 631.  His is a 634. So his experience may not apply to the 631. The kit may be absolutely wonderful for a 631.  Sorry about that.

But if the rear spring "guide" fits a 631 like his fit a 634 I don't think you'll be happy. I guess there is only one way to find out. 

The 631 and 634 both have center shaft piston so the kit want work in either one.

[bhh]

The 631 and 634 both have center shaft piston so the kit want work in either one.

Well, I don't have a 631 and never worked on one so I can't speak to that.

But the kit does work, (poorly) on the 634. The inner spring fits over the piston shaft and the outer spring fits over the inner spring. The factory rear spring guide is replaced with an aluminum stepped "guide" that both springs butt up against.

[pgritty]

Finally shot it over the chronograph. Light pellets (7.0) were in the upper 500's and 7.9 in the lower 500's. Tried a 9.8 Winchester pellet and it was in the upper 300's. Most accurate pellet was the Miesterklugen  pistol pellet. It was under .5" @ 10 meters.

I really like the way this gun handles.

Added some photos of the rifle. I need to touch up the chunk that is missing by the trigger. I would like to darken the checkering and then go over the rifle with some boiled linseed oil.

Pat