brand new stg556. federal value packs at walmart.

it only came with one 10 round mag, so i shot 10 of them.

i started on the regular gas setting. the first mag shot perfectly and the bolt locked back on empty mag.

next mag was perfect except bolt didnt lock back on empty.

third was same as second.

i then used a bullet to change the gas setting to heavy (for a dirty gun, underpowered rounds, etc), but it was the same. no jams of any kind, but the bolt didnt lock back.

i let it cool down a little while i shot the ar22 and pistol.

then i came back and did another mag, same.

changed the gas back to regular for the last couple mags, but same deal.


so all in all the rifle never jammed at all, which im happy about. the optic was right on out of the box. only problem so far is the bolt didnt want to lock back on empty. ive read that this is common with new guns and to run it on the heavy gas setting for the first few hundred rounds as its breaking in.

the e4 stock should be in any day now, and once i get it im going to go back and put 3-400 through it using p mags and usgi.

anyone have any other info on this that i should know about?

Mine didn't work OTB and Dave sent me a new trigger pack and had no problems. I'm also told that the BHO tab (metal thing on the fron of the trigger pack) can be stiff when new and need to be cycled by hand a few times to loosen up.

My E4 did exactly the same thing.  Lots of different ammo, differnt mags, different gas settings.  Dave spent a lot of time on the phone with me and ended up sending a new stock and a new trigger pack.  No luck.  I actually think it was just a "break in" thing.

Another thing to check is your cheek weld.  If you are used to NTCH cheek weld like on an AR, you will likely be contacting the BHO with your face.  Back your head off and/or take a more squared up stance, pull the stock inboard more to your neck.  

Mine runs 100% now...about 500 rounds in.