6mm AR broken bolt

[soloelcap]

This is an information post for those shooting the 6mm Grendel based round or planning to shoot it, not a troubleshooting post. Broken bolt lug next to the extractor.

A friend and fellow competitor at a HP Across the Course Match last month broke his bolt on a 6mm Grendel Match Rifle. Bummer, he was on his way to a High Master score. So this bolt he reckons had at least 5,000 fired on it through 3 different barrels. As far as I could see it was a retro 5.56 bolt and he didn't really know, he bought it used with his first 6mm Ar barrel in 2009. His pet load/control load was 27.5 H4895 with a Sierra 95 HPBT at around 2,750 fps.

Keep your speed modest and things don't break or blow up. That extra whatever in speed is only a click or so. Broken parts cost money and scores and bolts do wear out.

[Popeye212]

Thanks for the info.

[LRRPF52]

If shooting competitively for scores like that, why not change the bolt every time you change the barrel?

There is more bolt thrust with the 6mm AR because there is more bottle neck.

Working pressure needs to come down roughly 1000psi.

[soloelcap]

If shooting competitively for scores like that, why not change the bolt every time you change the barrel?

There is more bolt thrust with the 6mm AR because there is more bottle neck.

Working pressure needs to come down roughly 1000psi.

That is exactly what I asked him when I found out the bolt had been used in 3 different barrels. New barrel = new bolt and keep the old one as a spare. He could have called for an alibi, switched bolts and continued on.

Some guys don't like to fix it if ain't broke yet.