Bolt Wear Issue . . .

[MAP]

While cleaning one of my rifles tonight I noticed what appears to be etching or pitting on the bolt face. The rifle is 16" carbine length gas system. Round count on the bolt is approximately 7K will a vast majority being Federal XM193, some Winchester 55gn white box and fewer then 150 hand loads.

Any ideas?

http://i9.photobucket.com/albums/a89/MAP1911/feda73fa-0509-4581-b61d-bb2a364085d6_zps474838ef.jpg

http://i9.photobucket.com/albums/a89/MAP1911/274caecb-41dd-4981-8fec-205cad2c3e0e_zps2987524a.jpg

[Todd.K]

Gas escaping around the primer is cutting the bolt face.

[MAP]

Gas escaping around the primer is cutting the bolt face.

Thank you. Any issues in still using the bolt?


Mike

[BIGUGLY]

Keep using it, if you ever look up what is still in spec per military standards some bolts look pretty bad and I wouldn't use them but they are still useful and will function. I wouldn't worry about it. Keep shooting till it fails

[whiterabbit05]

I'm assuming after it wears deep enough you'll start having extraction issues.

[michael word]

Looks like your ejector is chipped and I would recommend replacing that part of the bolt.

[MAP]

I spoke with a friend today concerning the bolt. He thought it was caused by a primer failure. I checked my brass from the last range session and found this. . .

http://i9.photobucket.com/albums/a89/MAP1911/92bda006-088f-4a40-b8b0-8aae5b10d8dc_zps830e2c25.jpg

Looks like this could be the cause. No chip on the ejector.

Thanks to all who replied.

Mike

[Airhasz]

My 6920 bolt face looks similar to yours. The face is pitted in about the same spot and it's right at 10,000 rounds.

[Iraqgunz]

Who makes the bolt and barrel?

[MAP]

Who makes the bolt and barrel?

BCM BCG and Colt barrel.

Mike

[whiterabbit05]

That happened from just one primer? Find any other ones like that?

[Ned Christiansen]

I have at least one bolt like that, does not seem to be an issue.

[markm]

PPU. :rolleyes:

[MAP]

Only one primer failure.

PPU brass with my reloads.

Mike

[tucsonan]

Just out of curiosity have you checked your firing pin protrusion?

[kwg020]

Just out of curiosity have you checked your firing pin protrusion?

This. How hot are your hand loads would be my next suspect but I'd say Tucsonan has it pegged. kwg

[johnnychimpo]

I've gotten pierced primers in my handloads using Rem 6 1/2 primers. What primers did you use?

[mpom]

Would check firing pin tip as that part gets the escaping gas from a pierced primer first. If its rough and pointy, rather than rounded and smooth, expect more pierced primers.