So the weapon is this - >https://aselkonarms.com/urun/pcp-mx5/ pipe lenght is 550, with my silencer probably 700. Rifled barrer, twist rate 1:15. Stock shoots 840/890 fps / 61-62 joule AND assuming they have used 24 grain or something i think ?. Now it shoots those Jsb 33.95's @ 271 m/s average...