Replacing a complete fire control group can be quite expensive, thankfully JP Enterprises makes a trigger spring kit that will give your stock AR-15 a 4 to 4-1/2 lb trigger pull; with JP trigger parts the same springs will produce a 3 to 3-1/2 lb trigger pull. If replacing the entire fire control group isn't in your budget, or you just have too many AR-15s to justify a complete trigger kit in each of them, this trigger spring kit will significantly improve your stock trigger without breaking the bank. This kit includes a trigger, hammer and disconnector spring.