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Posted: 6/28/2006 5:41:19 AM EDT
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My friend and I were at the range the other day and half-way through we were picking up the brass. We both have RRA 16" midlenghts. We both assembled our lowers ourselves and bought complete uppers online. We noticed the rounds fired out of my rifle had "normal" primer strikes whereas primers from his rifle had the standard dimple, but then in the middle of the dimple was a little raised bump. The ammo we used as the test between the rifles was Lake City stuff. It happened with every type of ammo we fired out of the two rifles. Mine would be fine, and his would be dimpled with a bump. Question is: Is there something wrong with his firing pin? Is it something else? Should he be worried? He's had about 1000 rounds through it without problems but is worried this may be the signs of a problem in the future. Any help the guru's here could offer would be appreciated. I'd post pictures, but don't have a digital camera. |
| Take out both pins and compare. If in doubt swap them and try in each others guns.Are you running the same triggers and springs in your lowers? Another thing to check is fireing pin protrusion.Pull the carrier and bolt out of the gun,push the bolt into the carrier (where it would be when the gun fires and push the fireing pin foward with your finger.Difficult thing to measure but the two bolts should appear similar. |
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Not really a problem, nor the end of the world. On the center dimpled high spot ammo/rifle, when you pull the FP you will notice that the very center of the tip has a little center chunk missing from when it was produced and is causing the effect. Do you need to change out the FP?? Yes, in about 20,000+ rounds when either the tip breaks, or the FP protrusion is greater than .038 (stop collar wear). In mean time, you have a lot of shooting to do until you even need to think about a replacement FP. Now on the side note, I see that you are policing your brass, so thumbs up on keeping the range/shooter area clean. 
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