First, with SparkIV, export your WEAPONS.ivaud from resident.rpf (find it in
pc\audio\Sfx). Open the WEAPONS.ivaud with GTA IV-aud and import all sound files
to here (match the names):

PISTOL_SHOT1_L
PISTOL_SHOT1_R
PISTOL_SHOT2

Save once done and import back to resident.rpf, Save and close.

Now install this WeaponInfo line to Pistol line:

	<weapon type="PISTOL">
		<data slot="HANDGUN" firetype="INSTANT_HIT" damagetype="BULLET" group="PISTOL_SMALL" targetrange="50.0" weaponrange="325.0" clipsize="8" ammomax="112" timebetweenshots="333">
			<damage base="39.5" networkplayermod="3.0" networkpedmod="1.0"/>
			<physics force="30.0"/>
			<reload time="2000" fasttime="2000" crouchtime="2000"/>

			<aiming accuracy="0.5">
				<offset x="0.15" y="1.0" z="0.55"/>
				<crouchedoffset x="0.2" y="1.0" z="0.05"/>
				<reticule standing="0.65" ducked="0.55" scale="0.3"/>
			</aiming>

			<pickup regentime="240000" ammoonstreet="45"/>

			<controller>
				<rumble duration="150" intensity="0.1"/>
			</controller>

			<flags>
				<flag>GUN</flag>
				<flag>CAN_AIM</flag>
				<flag>CAN_FREE_AIM</flag>
				<flag>ANIM_RELOAD</flag>
				<flag>ANIM_CROUCH_FIRE</flag>
			</flags>
		</data>

		<assets model="w_glock">
			<anim group="gun@handgun" meleegroup1="firearm_core">
				<rates firerate="1.05" blindfirerate="1.05"/>
			</anim>
			<effects>
				<muzzle fx="muz_pistol_small"/>
				<shell fx="weap_ejected_pistol"/>
			</effects>
		</assets>
	</weapon>