West Coast,
Afraid not old chap. As discovered by the Germans in WW2 a well flown helo at low level is a very hard target for guns. Does an F14 want to slow down for BFM against a helo, esp one with a M134/M3M in the door? No, because the helo will out-turn it all day long (or until the F14 runs out of gas or is chased off by a friendly CAP). So the F14 unloads and extends out for a heater shot, only to find that re-acquiring the helo either visually or on radar is a LOT harder than he/she thought. Assuming that the helo is acquired the Heater engagement depends a lot on the quality of the IR AAM, the background IR clutter and the IRCM/DAS/IRSS fitted to the helo. Tactics can also be employed to significantly reduce the PK of the IR shot. Against most western RW DAS you would need to be packing a mighty good IR AAM for a high PK shot. However, what of the mighty AWG-9 / AIM-54 combo? Agreed, against a non-RWR fitted platform flown by non-EW aware crews (as proved in the Iran/Iraq war) the RF shot is a potent weapon. However, most radars have their weaknesses and the AWG-9 is no different and it can be beaten by a combination of chaff, terrain masking and manoeuvre. Finally, does a FJ pilot want to use his best self defence weapon (IR AAM) or expensive long-arm (RF AAM) against a helo? Depends on the mission I guess. The Iraqi helos shot down during GW1 were downed by CAS ac with spare ordnance (LGB/Cannon) and they were tactically inept and technologically deficient.
Before you ask, I have done an awful lot of Helo v Fighter instruction and training against a variety of FJ ac, from Alfa Jet/Hawk to Typhoon/F15 and have proved that the right kit and training make a helo a very difficult target to kill, particularly in a short opportunistic engagement. Interestingly, one of the points I used to emphasise to my studes was to use the FJ pilot's natural overconfidence against them....see Mr Fish's comment for a perfect example!