5.45 hammer spring with 556?

Is it ok to use the orange heavy s&w spring that comes with the 5.45x39 upper with a 556 upper? I got one for cheaper trainng ammo and use kns pins and don’t want to switch back and forth.

It won’t hurt anything, it’ll just make your trigger pull a little heavier.

Cool. The heavier trigger pull sucks but nothing I can do about that. Thanks Robb.

hope I am not stating the obvious, but it isnt rocket science to replace.

A bitch if you go back and fourth a lot(hence not worth it for potential to damage receiver if you dont know what you are doing) But if you are mainly in the .223/5.56 realm…

It will be switched frequently and as I stated I am using gen 2 kns pins and I like to put a drop of blue loctite on the screws.

Get a new lower… it seems you could get a designated lower for around $250 or so if you were willing to use some used parts. This might be easier in the long run. That is what I did with mine, it just wasn’t worth switching around.