Originally Posted by Too-many-hobbies
500fps?? Would that gas riffle be easy to de-tune for field use?
Yup. All you have to do is turn down the regulator. The main difference with gas rifles is that as you restrict airflow to reduce velocity via the regulator, you also reduce ROF.
As an aside, the owner of the particular rifle in that auction is a regular on www.classicairsoft.net