Lower flex when torquing buffer tube

[556Cliff]

https://geissele.com/reaction-block-...tube-only.html

I have one and I can't recommend it as it allows the lower to rotate while applying torque to the castle nut.

It's good for holding the lower while staking the castle nut though. However, I've been having mixed results with staking endplates lately, the heat treat is too hard on a lot of them, even the ones I've been getting through Colt. So instead of a nice little staking dimple I get the end plate warping and pushing down between the castle nut and the lower receiver.