Feed issues
 

I have two guns right now that are not feeding correctly on Semi. On full auto I have crisp powerful shots. On semi I will get one good shot at full power and then one shot that comes out around 45 FPS. The mags I use are feeding well.

Any ideas?

Need more info, what brand/model of gun, what kind of battery, what kind of ammo are you using?

One is a Classic Army M16 SPR.
The other is a KWA M4 CQB.

I use Matrix .23gr BB's and 9.6 nihm batteries in both.

Check the bucking, hop up chamber and barrel. Best suggestion I can give with the info provided.

Is your hopup adjusted properly?
If the hop is off, it would cause BB's to freely roll down the barrel and give you super low FPS on semi auto