105mm L7/M68家族有很多變種,看一下這篇, http://www.army-guide.com/eng/product3595.html The Rh 105-11 is also fitted with a muzzle brake and is sometimes known as the 105 SLR (SLR * Super Low Recoil). This gun is being advocated for a variety of light vehicles, possibly using a Rheinmetall autoloading system capable of carrying 15 rounds and firing 10 rds/ min. Although tested on a number of vehicles, the Rh 105-11 has yet to enter volume production and there have been no recent further applications for these guns. 理論上要做到超低後座力還是可能的。如果直接照搬M60坦克的M68是肯定不行的。