A few reports of it with 147s and 180s. Some consistently reported conditions are 4-groove and 6-groove rifling with square corners. I have yet to see a report out of a 5r barrel. Brux and Proof care common.
That said I've been running the 140s and 147s in a 4 groove brux and 4 groove proof and have had very few issues. 1 or 2 140s lost in the proof 6.5 SAUM (900 total rounds on it), nothing lost in the brux creedmoor. The brux knots factory match 147s sub .6" @ 100 for 10 rounds.
The 140s I lost were with heavy fouling in a match. Hot barrel. One time occurrence about 600 rounds ago on 1 stage of a match.
Would be a good idea to post barrel maker, rifling profile, twist, groove count, and if you can slug it and get land/groove dia.