03-28-2019, 12:21 PM
rwh Wrote:I broke two bolts on the same day loading 27.2 grains of 8208XBR behind a 123 grain Lapua Scenar with a CCI BR4 primer and Lapua brass. After that I pulled the bullets and checked the power weight. That load had been fine for me all summer but spiked badly on a hot afternoon in August. I've seen posts on this forum with hotter loads that that on this site. If you push the pressure in a grendel you are bound to break a bolt eventually.
rwh;
Personally, I believe it is basically not enough steel on the bolt when using a fat cartridge like a Grendel. Wish it wasn't so but you get to the point where you can't remove any more metal or even the slightest variation in something breaks the part. So guys spend a lot of effort ensuring everything is absolutely perfect when they build a Grendel upper and those uppers work but I dare say that no matter what you do with one, it will not last half as long as a average rack grade 5.56 bolt. I have come to the conclusion that those are the facts and if you want to enjoy a Grendel, have a spare bolt ready to go.
LR55