M5 not cycling correctly

[JeffL]

I recently bought parts and built an Aero Precision M5 308.  I put the lower together from a parts kit but bought the Aero upper from Delta Team Tactical already assembled.  It has a Luth AR 308 rifle stock kit that included the stock, buffer, tube and spring all came as a package.  When I first started firing it I was having cycling issues.  I cleaned and lubricated it several times and was still having issues.  Sometimes it fires and cycles the next round, but more often the rifle will not cycle the next round out of any magazine I've tried.  It will always eject the spent casing when it does fire. 

When it doesn't cycle, the BCG will be in the locked forward position after ejecting the fired round.  The top round of the magazine will have a scratch on it where the BCG came across it, but the scratch isn't the entire length of the casing.  This suggested to me the BCG is not going back far enough to pick up the next round.  I had read in an old post in another forum to trim a little off the buffer spring.  I tried this with no change.  I then cleaned and lubricated it again and checked the alignment of the gas block and everything was aligned.  ( I had previously already checked this)  I'm at loss how to fix it and now I have a one shot paper weight.  Any suggestions of what to try next would be appreciated. 

[Armed Eye Doc]

There are many possibilities for your problem.  I am going to direct you to this thread.

it will give the most common issues and the information that you will need to supply so that we can help you get your rifle running the way it is meant to run.  The more info you can provide up front, the easier it is to diagnose and offer suggestions to fix the problem.

 

[98Z5V]

21 hours ago, JeffL said:

Aero upper from Delta Team Tactical already assembled.

This company only deals in blem parts.  They buy bulk blem parts from other companies, then flip them to the consumer.

Do some research on the company.