25mm or 26mm

[darren m]

25mm or 26mm

 

i,ve been reading about 25mm and 26 mm piston size in the HW97.

anyway i think mine is a 25mm according to the serial no .

 

bit confused so got a few questions

 

why did HW change the size

 

why do some people prefer the smaller piston

 

when we say 25mm -- what is it refering too -- ie the piston , or piston head , or action / internal chamber size or all 3/4

 

would the spring size or guide be the same in either . also is it one breech seal for either.

 

just looked on chambers for 25mm stuff and it says no longer available

 

lastly if i wanted a v mach kit do i ask for a 25mm version or is it 1 kit fits all

 

sorry about all the questions , i had no idea there was a smaller size until researching serial numbers

 

thanks

[durbsguy]

The 25mm refers to the piston seal size.

 

My theory is the aspect of a small compression tube would would shoot sweeter as pressure = force/area, to expert the same pressure over a small area you would require a small force. So in theory you don't need as strong a spring and so the recoil would be lower and the gun should hence shoot sweeter.

 

When it comes to ordering a v mach kit you order the ones that are marked pre 144xxx odd.

 

I was led to believe that the pistons were changed from 25 to 26 for the US markets.

[darren m]

thanks , i,m going to borrow some digital calipers to double check mine .

 

in a 26mm surely the internal chamber thingy as to be 26mm also and same for the 25mm, or have i got it wrong.

 

so if i got a v mach kit it would just be the piston seal that was different sizes

 

thanks

[Jega]

Hi mate Weihrauch changed to the bigger piston seals (26mm) in rifles with serial No:-1446049 and over .Hope this helps.