To ensure that the centre-to-centre of the bolt hole patterns on either end of the brace is correct, we often recommend:

1. Drill holes in the HSCs for one end only then weld both HSCs to the tube followed by accurate layout of the hole in the HSC at the opposite end based on the actual position of the holes in the first end. Then drill the holes in the remaining HSC. This will negate any concern over weld shrinkage.
2. Consider using oversize holes in the gusset (only). This is allowed by code - an exception allows the use of oversized holes in one ply of connections of diagonal bracing members in Sections F1, F2, F3 and F4 in AISC 341-10 when the connection is designed as a slip-critical joint.
3. Make sure the erector surveys any critical items, such as anchor rods, before delivering the steel.