74OA said:
Yep, there's a reason why the sight and weapons still have an "X" designation.
They are still in development and undergoing evaluation by the Operational Assessment Team and will, as with most new designs, almost certainly have a number of improvements based on soldier feedback.
Whether those changes are paid for by the company or the Army will depend on, as you say, if they are covered or not covered in the government's original specifications.
It's not "in development," it's in production because Sig Sauer and Vortex were the winners of production contracts resulting from competitive prototyping. There is no R&D budget for modifications to the design and if Sig Sauer isn't meeting the thresholds, they are at-risk to find a fix or default.
The issues with reliability are mostly a result of the Sig 6.8mm ammunition and its >80kpsi chamber pressure. Barring a technological breakthrough in metallurgy, those weapons just aren't going to last as long or be as reliable as a rifle with a 56kpsi chamber pressure. Sig Sauer bet correctly that the Army would push aside issues of reliability and service life during the competitive evaluation of prototypes as long as the proposed designs could provide superior ballistic performance. Now the Army is getting what they asked for.
Like the IVAS program, the Army cannot afford to admit that it isn't meeting the performance specifications so, the program plods onward. The usual way these issues play out is that the fielding schedule is delayed, APUC will increase, and the quantities purchased may decrease. If the SecDef puts a focus on Defense Contracts Management Agency to do DOGE-like program audits, things might play out differently.