Here's my personally tweaked Milkor MGL 140 Grenade Launcher weapon line by me for 9SYcHO's Milkor MGL 140 mod.

If you have already tweaked your TLAD or TBoGT default.ide, then you need to change the gun@test_gun to gun@rifle. See below.
Before
w_e1_glauncher,		w_e1_glauncher,		gun@test_gun,	              1,	100,	0

After
w_e1_glauncher,		w_e1_glauncher,		gun@rifle,	              1,	100,	0

After that, go to WeaponInfo.xml and copy the new line below:

<!-- GRENADE LAUNCHER -->
	<weapon type="EPISODIC_1">
		<data slot="HEAVY" firetype="PROJECTILE" damagetype="EXPLOSIVE" group="GRENADE" targetrange="30.0" weaponrange="32" clipsize="6" ammomax="12" timebetweenshots="800">
			<damage networkplayermod="2.0" networkpedmod="1.0"/>
			<reload time="2066" fasttime="2066" crouchtime="2066"/>

			<aiming accuracy="1.0">
				<offset 				x="0.15" y="1.0" z="0.53"/>
				<crouchedoffset x="0.12" y="1.0" z="0.05"/>
				<reticule standing="1.0" ducked="1.0" scale="0.0"/>
				<ordnanceoffset pitch="0.1"/>
			</aiming>

			<pickup regentime="600000" ammoonstreet="3"/>

			<controller>
				<rumble duration="100" intensity="0.8"/>
			</controller>

			<flags>
				<flag>GUN</flag>
				<flag>HEAVY</flag>
				<flag>CAN_FREE_AIM</flag>
				<flag>ANIM_RELOAD</flag>
				<flag>ANIM_CROUCH_FIRE</flag>
				<!--<flag>CREATE_VISIBLE_ORDNANCE</flag>-->
				<flag>2HANDED</flag>
				<flag>HEAVY_WEAPON_USES_RIFLE_ANIMS</flag>
			</flags>

			<projectile>
				<typetocreate type="EPISODIC_5"/>
				<offset 	 x="0.55" y="0.0" z="0.08"/>
				<rotoffset x="0.0"	y="0.0" z="0.0"/>
			</projectile>
		</data>

		<assets model="w_e2_glauncher">
			<anim group="gun@rifle"/>

			<!--	<effects> -->
				<!--	<muzzle fx="muz_grenade_launcher"/> -->
			<!--	</effects> -->
		</assets>
	</weapon>

	<!-- GRENADE for GRENADE LAUNCHER (not usable as a thrown weapon on its own) -->
	<weapon type="EPISODIC_5">
		<data slot="THROWN" firetype="PROJECTILE" damagetype="EXPLOSIVE" group="GRENADE" targetrange="1000.0" clipsize="1" stattype="EPISODIC_1">
			<damage networkplayermod="2.0" networkpedmod="1.0"/>

			<projectile type="IMPACT" fusetime="15000">
				<explosion type="EPISODIC_1"/>
				<physics force="100.0"/>
			</projectile>
		</data>

		<assets model="w_e2_grenade">
			<effects>
				<trail fx="weap_pipe_bomb_trail"/>
			</effects>
		</assets>
	</weapon>

(Note that the line above [the second] works also with China Lake mod)
Have fun!