04-30-2013, 08:39 PM
I'm assembling a Grendel upper with a 264LBC 18" long BHW barrel that I bought on sale last year. I checked with BHW to verify that it was made to accommodate the Alexander Arms bolt assembly before I got the bolt. I finally have all the parts and assembled the upper, but the bolt won't go into battery (rotate to lock up). I checked with a Colt AR15 bolt and it will lock up. The Colt bolt lug length is about 0.276 - 0.277 inch. The Grendel bolt length is 0.278 - 0.279 inch with a bolt face depth of 0.133 inch, measured with a Harbor Freight micrometer (uncalibrated). I'm wondering if the lugs are too long.