It is the Pro Varmint stock in pepper laminate. I didn't have Boyd's do the pillars since they would only do the front due to the amount of stock material that needs to be removed at the rear, I used full size Remington 700 Score High adjustable pillars and did a full bedding job. I left a bedding pad ahead of the front pillar for added barrel support, it free floats from there, similar to what people do when they bed in CZ rimfires.
The accuracy from the original stock was decent for a micro-rimfire, and the Boyd's did improve the consistency of the groups over the factory stock but it was the pillars and bedding that really let the BMR show it's as accurate as my B-14R's. I'm not going to recommend you use the Score High pillars I did unless you're ready to remove a fair amount of the stock material both front and rear to get the pillars to fit properly. I don't know if I would have had as good of results with the accuracy with just the small front pillar from Boyd's, the action is very solid and stable in the stock now, zero movement, and 50 in-lbs ended up being the sweet spot on the action bolts. It took a bit of work but the accuracy improvement was well worth it.
I always thought that due to the size and polymer construction the factory stock was the weak link on the BMR. Properly stocked the BMR is capable of extremely good accuracy.