CM&MPC_ON BOLT

[newguy]

what do these letters mean on the side of a bolt.

I have a COLT bolt that has MPC on it and another bolt Im not sure of MANF that has just CM on it

[bkb0000]

CMP means it's a magnetic-particle inspected colt, and the other, CM is for Continental Machine... it's a CMT bolt.

[newguy]

Is the CMT a good bolt ?

What about for a spare?

[bkb0000]

CMT makes good parts.. if it doesn't have MP anywhere on it, it hasn't been tested for various flaws- but the rejection rate for 158C bolts is generally pretty dang low, as far as i've gathered. i keep a CMT bolt as backup myself.