Air Venturi Seneca double shot

A few weeks ago I bought my first air rifle. An seneca double shot 50 cal. After about 30 shots it starts leaking out of the barrels .is this a common problem ? I live in the netherlands in europe And there are no parts availeble here. Do you Guys have any idea where I can find parts ?
I bought mine from a guy on here about 5 months ago, I've shot the buckshot, steel balls, and arrows out of mine and I haven't had any leaks so far. Probably a bad seal. Is there any way you can take it back to where you bought it from and have them fix it?
 
I bought mine from a guy on here about 5 months ago, I've shot the buckshot, steel balls, and arrows out of mine and I haven't had any leaks so far. Probably a bad seal. Is there any way you can take it back to where you bought it from and have them fix it?
Thanks for your reply. . I cant take it back. Unfortunally. there are no spare party availeble for this type of rifle. I called air venturi they will not send anything .its stil a goodlooking gun so its gonna be a expencife decoration piece.
 
there are some youtube videos on the seneca guns, most of the orings are standard and can be found at hardware stores and stuff. Usually a really long flat head is required to get the stock off (i use a flat metal rod from a clamp)
if you need a valve seat or something, you might try bryan at veradium air https://www.veradiumair.com/
Thanks for your help . I have seen Some video’s. I dont think its complicated. Replacement parts can be the dealbreaker.