beavis_m305
Regular
- Location
- New Zealand
Took my DA556 upper to the range yesterday and found it was having an intermittent FTF. When loading a round from the left hand side of the mag it sometimes damages the cartridge and doesn't go into battery. It appears that either the bullet tip is hitting something on the way in causing the round to bend and/or something is squashing it just below the case neck. It does this with a different lower, different mags, different ammo, different BCG, shooting as well as manually cycling. There doesn't appear to be a set pattern.
I figured it might be something to do with the feed ramps, so I filed down the sharp edges so it is a smooth transition from mag to extension. It's still doing it, so I am wondering if anybody else had this problem with a Norinco/DA upper before. I'm gonna tear it apart to get a better look at the extension.
I figured it might be something to do with the feed ramps, so I filed down the sharp edges so it is a smooth transition from mag to extension. It's still doing it, so I am wondering if anybody else had this problem with a Norinco/DA upper before. I'm gonna tear it apart to get a better look at the extension.
