I fired primarily .308 in mine and never had problems.
You should keep the bullet weight below 180gr as was mentioned earlier but that's about it for ammo selection. Mine did really well with S&B 147gr.
If you are getting multiple shots for one trigger pull there is a problem. If you can't get them to warranty it then send it to a gunsmith that is good with m14's and have it repaired. It shouldn't cost much. Have him give it a nice trigger job while it's there. I bought mine used and it had been treated to a trigger job and it was really nice to shoot.
I wouldn't keep shooting it until it is repaired though. The range Nazi would be right asking you to stop shooting. It's one thing to have it happen and quit but it's an entirely different thing to keep shooting it when you know there is a problem.
Good luck
I was with MineMe when he got the rifle back from Epps. I thought it was a nonsense you selling a 308 rifle that can't shoot commercial ammo, not even talking about reloads.
We went to the range to test the rifle and the first double had happened when he was using MY chrono to check the ammo - Winchester, and thank God the two rounds went through the right area missing the chrono!
The chrono will always be available for you MineMe, but to use with your Norinco M14s!:-)
Is this the beginings of a love story?
I shot lots of ammo, including hand loads. Norinco Green box shoots well , keep or gun cleaned and greased , oiled .These rifles are a military grade rifles sold all over the world. Learn how to use your Iron sights . Only draw back about the gun its about 13 lbs when mount with a scope. Enjoy modifying and Shooting. I only shoot paper and dongs at the range with my rifle.
For all intents and purposes, they are the same cartridge. The Norinco M305B will quite happily cycle either round with no problems. Unless you are firing extreme bullet weights which might compromise accuracy, there is nothing to contraindicate using either caliber designation.
primer sensitivity is the main issue to be concerned with