This is based on the Turkish versions.
In an effort to determine the role that piston weight plays in terms of the guns velocity and recoil, I fabricated a nylon tophat to replace the solid steel one that the gun comes with. The new tophat had identical dimensions in an effort to maintain the factory mainspring pre-load.

Chrony results indicated a 30-50 fps decrease in muzzle velocity and little perceptible change in the recoil. It seems that the piston weight is such that minor reductions (like a lighter tophat) simply aren't enough to reduce the recoil. Machining the piston to reduce weight seems to be needed.
It is also evident that piston weight plays a large roll in obtaining higher velocity results and that a lighter piston assembly would sacrifice substantial power in exchange for a reduction in recoil. It is possible that altering the size of the transfer port might reduce the losses created by a lighter piston however, this can only be established through trial and error. Logically a larger diameter port should allow a lighter piston.

Anyhow, this is my experience. Your mileage may vary.

Russ

I actaully was toying with the idea of making the top hat of the Daisy Winchester a bit heavier to see how it they responded...  But the recoil part has been holding me back.  I actually did make a heavier top hat for the Gamo when I tuned it (it has a diameter a bit larger so that it precisely fits the piston), and although the results in power are positive, recoil DID increase (it's now a little less than the Winchester 1000X).  not sure if I will get around to it, though, now that I know that the power difference is not gonna be so great...

the piston weight reduction actually increased the recoil. I suspected as much but verified this once I returned the weight to normal.

Russ

To the end of the barrel in the form of a muzzle brake, and into the hollow in the rear of the stock if its a plastic stock.

if it is synthetic since these tend to be a little barrel heavy already. I've already managed to reduce my recoil to some degree but was mainly experimenting to find alternate methods.
A brake is handy in that it keeps our grubby paws of the barrel and protects the finish from the oils in our skin.

Russ

Muzzle breaks also look COOL!  HAHAHA!  But seriously, I find that they do make an improvement for scopes, as they put the sight out of the way (especially for night shooting if you have your light source on top of the scope; I have mine under the barrel, but I tried the scope way).

Felipe

I thought I would share the results of trial and error testing on my Hatsan powerplant.

Standard; the recoil was severe, it had a heavy walnut stock, and an underlever cocking mechanism.

Resultant configuaration; low or neutral recoil, increased fps.

due to: (Inspired by mate)inserted a small brass tube into the transfer port to sleeve down the size of the aperture to approx 3/4 its standard size (affixed with blue loctite, the brass tube was internally threaded. uses vortex/laminar flow theory). This increases peak pressure and heat at the breech, produces a better kick in the pellet's pants ( some enhanced/controlled combustion)and the piston is cushioned as it terminates its stroke thru the swept volume in the compression chamber, but does not bounce back appreciably.

Makes a sweeter more powerful shooting rifle altogether.

hope this is useful.

GS

was wondering if u could give me more info on what size brass tube what the threading size was and how much more power

oh and what was the actual reduction of the recoil was it it worth the effert

The two are like chalk and cheese.

We are talking about a Hatsan mod 100.

Any port sleeve will have to be tailored to the specific model.

Its definitely worth the investigation. I will post shortly on the thread size.

GS