Marvin Hullinger

Hi Everyone: I found that the bolt does not come back enough for the bolt catch to work. I took out the buffer and spring, re-attached the lower to the upper, pulled back on the charging lever and got the bolt back behind the catch. As 98 suggested, I need a 2.5" buffer, 4.5 oz. I looked at the gas tube and it extends into the chamber just as the one in your picture. I do not see any 2.5" buffer in the chart, above. Any suggestion on sourcing a 2.5" buffer, 4.5 oz and the proper spring? Should I keep using the 7" internal depth receiver extension? Mr 98, You mentioned a sweet set up in your chain of posts. What internal depth receiver extension did you use? You mentioned a 5.2" , 5.4 oz. buffer. I see a spring in the chart, above with a 5.2" buffer. Was that the spring that you used? I really appreciate how you guys have helped me out! Thanks!

Any manufacturer, model number for a castle nut wrench?

The buffer is 3.25" long and the internal measurement of the receiver extension is 7". Thanks to 98Z5V and dpete! Please advise on what I should get for proper operation: 1. 2.5" long buffer weighing 5.4 oz, Please; suggest manufacturer, part number? 2. action spring, what spring weight? Please; suggest manufacturer, part number? 3. I have a 7" internal measurement receiver extension, Should I keep it or get another? Please, suggest manufacturer, part number? Thank-you SIRS !!! Thank-you forum.308ar.com !

Thanks all for your valuable comments. 1. The gun was purchased from a dealer/assembler on the other side of the US; unlikely they will get it back via shipment for analysis and repair. I have made numerous attempts for feedback from them but get only silence. 2. The bolt is not held back when pulling the charging handle all the way. The chamber is not open after shooting. I have not been able to shoot more than one round through the gun at a time as it does not cycle. I have tried to hold out the bolt release "button" and slowly allow the bolt to catch. It slightly catches but when releasing the charging handle ever so slowly the bolt goes all the way. 3. I have another 308, a Sig and will compare the length of the buffers. If they are the same, then the buffer is not for an AR15 (which is longer). 4. The bolt release mechanism appears to be ok. Can anyone see any issues from the pic? 5. The Sig 308 has a lighter gauge spring, which has less of a force than this gun. Would a spring replacement be needed with a BCG upgrade, assuming the BCG weights less than the standard one? Anyone have any other ideas? Thank-you so much for your help. I have tried to find a local gun smith but most are not working due to covid.

Here are pics of the bolt, bolt catch, buffer & action spring. Trigger is ATC Tin adjustable trigger. BCG is Tin.

The gun was purchased from a dealer that assembled it, They put in the upgraded Tin adjustable trigger and the Tin BCG. The gun did not properly cycle from the first shot. I checked the bolt release mechanism with the lower unattached to the upper to observe the mag pushing against the bolt catch. It looks ok.

I recently purchased a 308 with upgraded trigger and BCG. First time shooting out of the box, the gun did not cycle properly. Took the action spring out and pushed the BCG against the held up bolt release and the BCG slipped by it. I noticed on my Sig 308 that the BCG front is cut square across the face that contacts the bolt release catch, the new 308 upgraded BCG has an angle cut at a diagonal where it appears that a straight face would hold. I put the lighter action spring from the Sig into the new gun and it still did not hold. Any suggestions?