I’ve purchased two uppers from WOA a 16” SDM and an 18” SPR.
The SDM averaged 1.7 MOA for 10 round groups with 10 different handloads, it averaged 7 of the 10 rounds into 0.97 MOA, with the three fliers opening it up to an average of 1.7 MOA. I returned the upper twice and the second time WOA refunded the purchase price. To clarify I measure the best 7 out of a 10-round group and record that information too.
The 18” SPR averages 1.23/0.81 MOA for 10/7 round groups, it’s delivered one group at 0.59 MOA for a personal best.
Out of 58, 1x10 groups fired at 100 yards from a bench with front and rear bags, 10 of them are sub moa, most in the 8’s and 9’s the 0.59 MOA group was exceptional.
After about 2600 rounds it just delivered a 1.05/0.70 MOA for a 2x10 with an average mean radius of 0.377”, I’ve had 8 AR barrels and this barrel has given me the best performance yet, even outperforming a 16” Bartlein from Craddock which is holding the #2 slot.
During load development with 5 shot groups my personal best is 0.418 MOA with the 18” WOA. Developing loads and shooting 10 round groups out to 500 yards with an AR15 has become a hobby in my old age.