Jimbo from United States, NV Public Profile

There are two types of AR15 builders/maintainers... Those who have lost a spring or detent pin, and those who will.
Sooner or later, it will happen... During assembly or reassembly of your favorite AR15, the energy stored in a spring you are installing will be unexpectedly released, causing the spring (and perhaps its associated detent pin) to launch like a Trident missile into regions of your workshop where no man has gone before. A corollary to Murphy's law states that the probability of locating its resting place is inversely proportional to the importance of the spring.
What to do? If you have this kit, the project continues. Otherwise, it's on hold till you track down a replacement. This kit provides spare springs and pins to allow the rifle assembly to be completed after turning the air only SLIGHTLY blue... Reasonable cost insurance against the inevitable.

Bought this to use on the bench for setting up and zeroing scopes on standard and AR platform rifles.
PROS
Easy assembly
Clever design
Good materials and finish
Simple construction
Well made
Wide range of adjustments
CONS
Too susceptible to recoil - Unusable without a bag of shot to hold it down
After assembly, unit has too much "slop" in the various parts. Difficult to adjust to hold a point on the target.
Rifle butt too loose in its holder, needs to secured.
Rifle fore end restraint loose, needs adjustable lateral support
After barely being able to hold an 8 inch circle at 100 yards with both my AR and bolt action Weatherby .223, I went back to my Caldwell sandbag rests and adjustable fore end support and accuracy returned to normal.
BOTTOM LINE
It will require a fair amount of futzing around to tighten it up and secure the rifle, and there is no sense in using it without a bag of lead shot to manage the recoil