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Posted: 3/20/2004 6:24:23 PM EDT
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I have a Bushmaster rifle with a titanium firing pin I put in. I went shooting the other day -about 300 rounds winchester Q3131a ammo lot TD22 expended with approx. 5 failure to fires {light hits on primer}. When I broke down rifle at the end of the day the firing pin was dirty with carbon and a little oil. Is the firing pin too light ? or is it the ammo? |
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Put the stock pin back in, you gain nothing with the Ti unit. The light hits are more likely due to the bolt not totally locking up in the barrel extension. Perhaps some crud in the chamber, lug recess, or oversize/dirty cases. If the bolt isn't completely locked up, the firing pin doesn't protrude from the bolt face far enough to set off the round. It is designed like that to prevent out of battery discharges (and resultant destruction of the weapon). |
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Do not oil up your firing pin. The oil will induce drag that will interfere with proper operation. It will also attract and retain carbon residue that will cause it to drag and stick even more. The light strikes you were seeing were more then likely caused by the crap and crud that was on the firing pin and in the channel. btw, ditch the Ti firing pin. |
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Firing pin protrusion out the face of the bolt should be from .032 to .038. If you check the TI pin, your going to fine that it may be too short, and shallow firing pin bolt protrusion is causing the problems. As for the TI pin, since you bought it, you may as well get your money out if it. Just watch the tip of the firing pin; it will be the first to go. To set the pin to the correct protrusion, pull the bolt and shove the firing pin in and bottom it against the back of the bolt, then mic the amount that of the pin tip that stick past the bolt face. To add protrusion, just chuck it up in a drill (tip into the drill), and spin file the face of the stop collar (keep it square) until you get the correct protrusion. If you go too far, then just spin file/spin sand the tip down to get it within specs. As for removing metal on the back of the bolt, leave it alone. When the TI pin goes south, you can just drop the old pin back and be up and running in a minute or two. Note: Once the tip shatters during use of the TI part, don't try to save the pin by reworking the tip and stop collar. The stress fracture of the metal will be well below the point that cracked/shattered off. P.S. Just to let you know, normally I would say to chuck the TI pin in the trash, But with this being your first post, and me having to Point/counter point, and everyone already telling you to throw it away, figured I would I would play the other side of the coin and tell you how to correct the problem. Oh, Welcome to AR15.com. |
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If you want to Mic the Firing pin protrusion so I know how far to turn the stop collar, I can get to it in a few months when I get back to the shop (No charge). Seems that you have started an Anti-TI firing pin response that guys are using to resolve problems on every rifle problem posted. Would love to correct the pin just to quite them down a bit. Also, a bit of back ground on the pin. The theory is that the TI pin decreases the lock time of the rifle. Lock time is from when the trigger is pulled, to when the primer is ignited. The problem to this is the firing pin only moves a faction of an inch (very, very little reduction in lock time). The really lock time reduction is to decrease the mass/weight of the hammer (longest moving part), but the TI will not hold a edge very long (trigger/hammer sear), so no one has yet to try and build a hammer out of TI, only reduce the weight/mass of the standard hardened steel hammer. |
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