I ordered a set of go/nogo gauges in 556 nato and 300 blackout, yesterday i deiced to take my 556 and 300 blackout AR and try the gauges.
I first took out the ejector and extractor on my 556 and placed the go gauge in the chamber, proceeded to insert the bcg, it failed to close. I then tried the nogo gauge and same thing, they both left the bcg protruding from the back of the receiver the same amount.
I then decided to try my 300 bolt which is also a 556 bolt, i pushed in the bcg and it passed on the go and failed on the nogo which is what you would expect. I put this bolt back in the 300 blackout upper and placed the 300blk go gauge in the changer and it passed on the go and failed on the nogo which is again what you would expect.
I then took the bolt from the 556 ar and tried the 300 blackout go/nogo and all is good. So i have now swapped the bolts so that the go gauge passes in the 556 and 300 blackout.
I did clean the bolts,chamber,barrel on both before doing this test. I just find it strange that the 556 bolt with the 556 barrel fails but works with the 300 blackout, anyone come across this type of situation?
The barrel in the 556 is S&J barrel, 300 blackout is custom barrel.
To summarise, 300 blackout barrel both bolts work as they should with go/nogo but the 556 barrel only 1 of the bolts will work with go/nogo gauges.
I first took out the ejector and extractor on my 556 and placed the go gauge in the chamber, proceeded to insert the bcg, it failed to close. I then tried the nogo gauge and same thing, they both left the bcg protruding from the back of the receiver the same amount.
I then decided to try my 300 bolt which is also a 556 bolt, i pushed in the bcg and it passed on the go and failed on the nogo which is what you would expect. I put this bolt back in the 300 blackout upper and placed the 300blk go gauge in the changer and it passed on the go and failed on the nogo which is again what you would expect.
I then took the bolt from the 556 ar and tried the 300 blackout go/nogo and all is good. So i have now swapped the bolts so that the go gauge passes in the 556 and 300 blackout.
I did clean the bolts,chamber,barrel on both before doing this test. I just find it strange that the 556 bolt with the 556 barrel fails but works with the 300 blackout, anyone come across this type of situation?
The barrel in the 556 is S&J barrel, 300 blackout is custom barrel.
To summarise, 300 blackout barrel both bolts work as they should with go/nogo but the 556 barrel only 1 of the bolts will work with go/nogo gauges.
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