One of my complaints with the 516 was the fact that the gas valve became difficult to adjust and/or remove once the valve body was fouled. I see with some interest that SIG has changed the gas block and valve on the 516 to resemble that used on the 716.

The valve on the 716 has lugs rather than threads that hold it in the block. Depressing a detent and rotating the valve 180-degrees frees the lugs from the block and it has been my experience that the 716's valve is easily removed.

I'm glad to see this change to the 516. I'll have to see if I can't find a fair price on one of the new style rifles.