Well it does exactly what the name implies it prevents chopping.
its not the best choice for an lp setup and no o-rings increase efficiency
It is an excellent product but is unfortunatly a little rare. Also it will help immensely to prevent from chopping. It is made of nylon so no lube is needed, and is lighter than the stock bolt. It also requires a cocking rod if you want to use it as rear cocking.Worked pretty good if you find you are constantly chopping and if you can find one online I'd buy it quickly.
Good all around product. I would really sugest you buy it if you could find one