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Posted: 11/23/2009 7:13:24 AM EDT
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My wife has a Compass Lake Upper. It FTF/FTlock bolt some times
Is a major problem in a Service rifle Match during rapid. I tried lots of things. Went to new LC brass loads, took it to the range yesterday it still failed to lock bolt to battery when it got hot. Looked at the bolt face and the end of the barrel They were shinny rub marks on both. Is this normal?? Other than this it shoots one hole groups, damn thing. Any Ideas? Thanks |
| What are the specs on the set up,what mags?,ammo?type of carrier?buffer?failing to lock could be anything from low gas pressure to tight oversized parts or bad mags..failure to feed could be bad mags,weak recoil spring or need of a heavier buffer?...need more info.Too tight a chamber whats the barrel specs on the chamber?match,wylde or Nato?The bolt face will wear and the end of the barrel if the crown was damaged you wouldnt be getting 1 hole groups thats for sure.Its happening when it gets hot..metal expands when hot so could be a real tight chamber,that will effect extraction and feeding also check the barrels feed ramps on the extension. |
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I know just enough to be dangerous and am no expert,but I throw this out there anyway.
Is that a custom made barrel assembly....as in fitted or matched bolt/barrel? If so the tolerances of the bolt in the barrel extension will be tight for accuracy purposes.Its my understanding that actual hand fitted match bolts and barrels are setup so that the bolt face rests on the breech of the barrel when in battery rather than the cartridge head to improve consistency.So tolerances are tight I'd say,and will need a good break in period. As far as the rub marks on the bolt lug face and barrel breech face,if light minor polishing of the surfaces is what your seeing I'd say its normal. One other thing Ive seen vary is the length of the lugs on bolts.That is from the rear locking surface of the bolt lug to the front face of the lug.Ive seen them range from .272"-.278" in length and as result some fit tighter in the barrel extension than others.The difference is in how much material was ground off the front of the bolts in manufacture.Those at the .278" in length tend to bear more against the breech face of the barrel when going into battery and show more polishing to the surfaces. So that might be something to eye ball as well. Otherwise I'd call the manufacturer and see what they say about the assembly before I did anything else. HTH |
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This rifle has about 1500-2000 through it. Break in should be done.
Being cheap and having lots of once fired Winchester brass I started using it to keep track of my wife's brass. I used LC. It has had problems on and off for is seems since we got it. Polished the chamber with .3 micron polishing compound. It's a mirror in there. I went to Winchester new brass and that helped, but it would FTF or FT extract sometimes. Went to new LC and it extracts fine, but now fails to lock bolt to battery with new LC cases when it gets hot. Very frustrating to wife when she is in contention for leg points. Would it need a stronger recoil spring? Next trip to the range will be with an extra new BCG. |
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