AK-47AK-47, Blueprints, Construction and Blueprints
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//-->Headspace Checks OnAK-47/74 Type RiflesWhat to expect from your headspace gaugesHopefully, I will be able to tell you what to expect from your headspace gauges. First and foremost I amnot an “EXPERT”. There will always be people that know more or less than I. You will have toremember that AK’s are “NOT” manufactured to the close tolerances that U.S. made AR-15’s, M-14’s orbolt action rifles are. Knowing this will allow acceptance of tolerances that would not be acceptable fromU.S. manufactured firearms. I’m not going to get into manufacturing processes, which is better, SAAMIor CIP or any really heavy handed technical stuff. Also, I not a professional photographer so please barewith the pictures.First, let’s defineBolt LockupandFull Bolt Rotation.Bolt Lockup(Picture #1) is when the bolt moves the maximum distance when being closed by the boltcarrier. This is what happens when you pull the bolt carrier back to charge the rifle and let it go to feed around into the chamber. In another words, this is the normal operational sequence of the bolt and boltcarrier working together.Full Bolt Rotation(Picture #2) is when you insert the bolt into the front trunnion and rotate it till itstops.These are two and independent dimensions/operations. Also they will give you different indications ofbolt movement. Since were interested in headspace checking only,Full Bolt RotationwillNOTbeaddressed.Setting up to check the headspace on the AK47/74 type riflesFirst and foremost the firearm must be safe. Remove the magazine, pull the bolt carrier to the rear andinspect the chamber to ensure that the chamber is empty.Working tip, these operations are mucheasier with the recoil spring removed.With the bolt carrier in it’s most forward position, check to seewhere the bolt has stopped in relationship to the front trunnion. I make a reference mark on the fronttrunnion and the bolt (Picture #1). You are now setup to check headspace.Pull the bolt carrier to the rear just enough so that the bolt has does not engage theejector. Slide the “GO” gauge into the bolt head recess (it can be held by the extractor), then slowly (IMEAN SLOWLY)allow the carrier to move forward to chamber the “GO” gauge. When the carrier hasstopped moving, check the reference points mentioned in “Setting Up”. They should match, indicatingthat the rifle has passed the “GO” check (Picture #3). But remember that were talking about an AK-47/74type rifle so there might be just a very, very small difference in the two reference marks. Pull the boltcarrier back and remove the “GO” gauge from the bolt.“GO” Gauge…“NOGO” Gauge…Pull the bolt carrier back as stated above and insert the “NOGO” gauge.Againslowly move the bolt carrier forward until it stops. The bolt reference marks should not align (Picture#4). At this time the “NOGO” check has been completed. If the reference marks align it means that thechamber is getting close to the maximum allowable size set by the manufacturer. If this is the case youhave two (2) options.Option 1:Option 2:Obtain a “Field” headspace gauge to accomplish the same check as stated above to ensurethat the reference marks will not align. This gauge indicates the maximum “SAFE” chamber dimension.Replace the barrel assembly.I personally feel that if the bolt aligns with the reference marks when usingthe “NOGO” gauge the firearm is not safe for use. A new barrel is cheaperthan a new face. [ Pobierz całość w formacie PDF ] |
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