Carbine Reliability Enhancement Kits are the cure for your sluggish carbine. Few of the aftermarket carbines use the correct extractor spring or the correct black Extractor Spring Insert. Most come with a rifle extractor spring and the rifle's blue insert. These are fine for the M16A2/A4 rifle, but insufficient for the M4 and similar carbines. Both REK #1 and #2 come in a small zip loc bag that can be carried in your pistol grip, Vertical Fore Grip or with your load carriage equipment.
The REK #2 includes: Wolff Extra Power Extractor Spring Black Insert Crane "O" Ring 3 Bolt Gas Rings
To test for worn bolt gas rings, remove the firing pin retainer pin, firing pin, and bolt cam pin. Hold the bolt carrier in one hand, and while placing your other hand underneath, invert the bolt carrier so that the bolt is facing down.If the bolt moves on its own, you need to replace the bolt gas rings.
NOTE: You do not need to misalign the bolt gas rings. That is a myth and has no basis in fact. If it makes you feel better, have at it, but it accomplishes nothing.
