i bought 2. one for my dreadnaught, and one for my psa. turns out my pivot pin on my psa is "out of spec", it was built from random parts. the pin fits in the lower kinda tight, but will not fit in the upper. i even removed the pin, getting in back in is gonna suck, but even after removal it will not fit in the upper by itself. the upper fits like a dream on my dreadnaught though. odd that my pivot pin is out of spec, but it was a random part.