Thanks Claven and M14 Doctor.
The bolt is very tight and the spacing on closing is way more than a few thousandths from the bottom of the bolt lug to the receiver. It is more like 1/8". I've been have been lapping the bolt bolt now (what a job too!) to the point where it is about .025" from the bottom.
The head (front) of the bolt however is NOT making contact with the barrel, nor are the front of the lugs making contact with the front of the receiver. I inspected the norky bolt and compared it to the 7.62 bolt. The measurements (as incomplete lapping) are as follows:
Right Lug OAL: 7.62 = 0.568" Norc = 0.540"
Left Lug OAL: 7.62 = 0.452" Norc = 0.440"
Both lugs on the 7.62 are considerably longer and the norcy bolt, at some time during the cycling, was making contact with the barrel and the front of the left lug was contacting the front of the receiver (from the wear marks). It also flopped around pretty good in the action (about 10 thou or so) and the receiver lug was pretty polished from shooting.
I will be finishing the lapping tomorrow. The go gauge is still good, the receiver/bolt lugs are still too tight. I still have about .025" worth of lapping to go before the bottom of the right lug makes contact with the receiver.
The right bolt lug face has really good contact with the receiver, but the left one is still not quite full (only about half the lug is touching, like there is a peak or something like that in the middle of the lug. I may gently file it to try and get a more even bearing surface between this lug and the receiver.
Since I suspect that more metal on the receiver and lug must obviously come off to properly seat, I also suspect that some of the "hard" metal you guys described (on the receiver) has been worn away by the lapping and previous shooting. Material is obviously being removed by the lapping process (but in both cases very time consuming as that metal is hard as hell - even for file).
If that is the case, my question is what will be the ramification of taking too much off. The receiver and bolt lugs would not be in any danger of shearing, so would I just see the metal on the receiver and bolt lugs "pounding out" sooner than should be? What is the "normal" lifespan of these bolts?
I'm kinda curious now.
The bolt is very tight and the spacing on closing is way more than a few thousandths from the bottom of the bolt lug to the receiver. It is more like 1/8". I've been have been lapping the bolt bolt now (what a job too!) to the point where it is about .025" from the bottom.
The head (front) of the bolt however is NOT making contact with the barrel, nor are the front of the lugs making contact with the front of the receiver. I inspected the norky bolt and compared it to the 7.62 bolt. The measurements (as incomplete lapping) are as follows:
Right Lug OAL: 7.62 = 0.568" Norc = 0.540"
Left Lug OAL: 7.62 = 0.452" Norc = 0.440"
Both lugs on the 7.62 are considerably longer and the norcy bolt, at some time during the cycling, was making contact with the barrel and the front of the left lug was contacting the front of the receiver (from the wear marks). It also flopped around pretty good in the action (about 10 thou or so) and the receiver lug was pretty polished from shooting.
I will be finishing the lapping tomorrow. The go gauge is still good, the receiver/bolt lugs are still too tight. I still have about .025" worth of lapping to go before the bottom of the right lug makes contact with the receiver.
The right bolt lug face has really good contact with the receiver, but the left one is still not quite full (only about half the lug is touching, like there is a peak or something like that in the middle of the lug. I may gently file it to try and get a more even bearing surface between this lug and the receiver.
Since I suspect that more metal on the receiver and lug must obviously come off to properly seat, I also suspect that some of the "hard" metal you guys described (on the receiver) has been worn away by the lapping and previous shooting. Material is obviously being removed by the lapping process (but in both cases very time consuming as that metal is hard as hell - even for file).
If that is the case, my question is what will be the ramification of taking too much off. The receiver and bolt lugs would not be in any danger of shearing, so would I just see the metal on the receiver and bolt lugs "pounding out" sooner than should be? What is the "normal" lifespan of these bolts?
I'm kinda curious now.
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