For me . . . 3% is acceptable. The rest are culled or tossed.
I am fortunate in that before I retired I swooped up a bunch of LC72 MATCH (7.62) and TW73 all same lot # 5.56.
I prepped the 5.56 for my 223Rem's and it is super accurate.
Never heard of a 14gr difference in 223 brass. And PMC is usually great brass from what I have heard. --- SAWMAN