02-25-2014, 04:28 AM
Has anyone had a 6.5 Grendel bolt shear a lug after only 123 rounds?
I am flabbergasted.
The original LBC bolt sheared after shooting Wolf 120 gn MPT with a suppressor. The bolt was replaced with a second LBC bolt and a variety of loads followed, no suppressor, no pressure signs: 139gn Scenars with N540 to 28.0 gn (MAX 28.1), 123 gn SMKs with 28.3 gn 8202XBR (28.5 gn is MAX), then 24 rounds of the Wolf and a lug sheared.
Having seen other people's expensive guns explode with cheapo ammo, we never use cheapo ammo in our expensive guns. I didn't consider the Wolf ammo "premium," but neither did I think it was "cheapo."
Since the rifle has been properly and professionally headspaced, gassed, and reinspected, and the LBC bolt dimensions are correct, here's my differential diagnosis:
inherently weak design of the 6.5 Grendel bolt
poor metallurgy of the LBC bolts
bad lot of Wolf (?lot # 485.E30-1400693)
Other possibilities?
After the first bolt sheared, I ordered 2 LBC bolts and finally a regular AA and 2 hard use AA bolts arrived, so I am in a position to try the AA bolts.
I am flabbergasted.
The original LBC bolt sheared after shooting Wolf 120 gn MPT with a suppressor. The bolt was replaced with a second LBC bolt and a variety of loads followed, no suppressor, no pressure signs: 139gn Scenars with N540 to 28.0 gn (MAX 28.1), 123 gn SMKs with 28.3 gn 8202XBR (28.5 gn is MAX), then 24 rounds of the Wolf and a lug sheared.
Having seen other people's expensive guns explode with cheapo ammo, we never use cheapo ammo in our expensive guns. I didn't consider the Wolf ammo "premium," but neither did I think it was "cheapo."
Since the rifle has been properly and professionally headspaced, gassed, and reinspected, and the LBC bolt dimensions are correct, here's my differential diagnosis:
inherently weak design of the 6.5 Grendel bolt
poor metallurgy of the LBC bolts
bad lot of Wolf (?lot # 485.E30-1400693)
Other possibilities?
After the first bolt sheared, I ordered 2 LBC bolts and finally a regular AA and 2 hard use AA bolts arrived, so I am in a position to try the AA bolts.