Print the forward assist version if you have a forward assist installed on your rifle. Otherwise, the standard lowers will be more robust (since lowering the shelf increases a stress concentration in the lower).įor all the high and low-shelf variants, there are two sub-variants – lowers that have a cutout for the forward assist, and lowers that do not.
Print one of the low-shelf models if you use an FRT trigger or other device requiring a low-shelf receiver. UBAR2 and UBAR2C have four sub-variants: high-shelf options and low-shelf options. Printed Parts Checklist:įour variants are the UBAR2, and four are the UBAR2C – the “C” designation indicates that the lower has a little extra clearance required for some side charging/billet/nonstandard uppers. Using a U-Bolt to reinforce the rear tower and rod end eye bolts to reinforce the front takedown lug, the UBAR is a contender for the strongest printable AR15 lower design at its time of publication. At the core of the UBAR’s design is its simple reinforcements – using hardware store metal parts solves the major design concerns that printed AR15 lowers face.
