hi all calabert 40 here. just got my sparta from dave at high caliber services corp.great guy exallent to deal with . very pleased will deal with again .first impressions.well after a hour of smiling and jumping for joy , the wife beat me back to reality with a broom stick.i took a really good look at this thing.its built like a brick sh''''t house . really strong ,seems a little heavy. no twisting here. thick body , and the aluminum rail is very robust .you can bash heads with this thing.the rail seams to be attached to the body very solidly. so as long as the fit is tight with the receiver , all will be fine. im sure there are ways to screw or pin , bolt the receiver etc. to make a solid union in case of some movement.im going to camo mine first as its my 200 yard and under yote gun.then ill test it out .im still waiting to get into a gun club close by , but i cant get acess till they call me to do there safety course.ill post a video on you tube . try to get some real good close ups of it ,and all that stuff.thanks again hical . what ever the outcome , good or bad your service was very nice. cheers.