Never had a problem with a SAS bolt, it's pretty big . Must be a recent manufacturers defect.
Some only look at one side of the story...I am still trying to find out what screw is breaking and what is he doing when it breaks, Cocking? Taking the rifle apart? Let us know exactly what you did that causes the screw to fail, then we can better help. You can not blame an entire company when some goes wrong of else if we took others advice there would be no more airgun companies to buy from because they all fall short in some way or another.