diff --git a/source/src/entity.h b/source/src/entity.h
index 18659e77..ac4513e6 100644
--- a/source/src/entity.h
+++ b/source/src/entity.h
@@ -100,14 +100,14 @@ struct physent
     int timeinair;                      // used for fake gravity
     float radius, eyeheight, aboveeye;  // bounding box size
     bool inwater;
-    bool onfloor, onladder, jumpnext, crouching, trycrouch;
+    bool onfloor, onladder, jumpnext, crouching, trycrouch, cancollide;
     int lastcrouch;
     char move, strafe;
     uchar state, type;
     static const int crouchtime;
 
     physent() : o(0, 0, 0), yaw(270), pitch(0), roll(0), pitchvel(0),
-                crouching(false), trycrouch(false), lastcrouch(0), state(CS_ALIVE)
+                crouching(false), trycrouch(false), cancollide(true), lastcrouch(0), state(CS_ALIVE)
     {
         reset();
     }
@@ -480,11 +480,12 @@ struct grenadeent : bounceent
     bool local;
     int nadestate;
     grenadeent (playerent *owner, int millis = 0);
-    void activate(vec &from, vec &to);
+    void activate(const vec &from, const vec &to);
     void _throw(const vec &from, const vec &vel);
     void explode();
     void splash();
     virtual void destroy();
     virtual bool applyphysics();
+    void grenadeent::moveoutsidebbox(const vec &direction, playerent *boundingbox);
 };
 
diff --git a/source/src/geom.h b/source/src/geom.h
index 15c0af2b..58d07d41 100644
--- a/source/src/geom.h
+++ b/source/src/geom.h
@@ -17,6 +17,7 @@ struct vec
 
     bool operator==(const vec &o) const { return x == o.x && y == o.y && z == o.z; }
     bool operator!=(const vec &o) const { return x != o.x || y != o.y || z != o.z; }
+    vec operator-() const { return vec(-x, -y, -z); }
 
     vec &mul(float f) { x *= f; y *= f; z *= f; return *this; }
     vec &div(float f) { x /= f; y /= f; z /= f; return *this; }
diff --git a/source/src/physics.cpp b/source/src/physics.cpp
index 53b64a86..ef813bbf 100644
--- a/source/src/physics.cpp
+++ b/source/src/physics.cpp
@@ -63,7 +63,7 @@ physent *hitplayer = NULL;
 
 bool plcollide(physent *d, physent *o, float &headspace, float &hi, float &lo)          // collide with physent
 {
-    if(o->state!=CS_ALIVE) return true;
+    if(o->state!=CS_ALIVE || !o->cancollide) return true;
     const float r = o->radius+d->radius, dx = o->o.x-d->o.x, dy = o->o.y-d->o.y;
     const float deyeheight = d->dyneyeheight(), oeyeheight = o->dyneyeheight();
     if(d->type==ENT_PLAYER && o->type==ENT_PLAYER ? dx*dx + dy*dy < r*r : fabs(dx)<r && fabs(dy)<r) 
diff --git a/source/src/protos.h b/source/src/protos.h
index 76bbb0eb..28c1f5e2 100644
--- a/source/src/protos.h
+++ b/source/src/protos.h
@@ -419,12 +419,12 @@ enum
 extern void particleinit();
 extern void particlereset();
 extern void particle_flash(int type, float scale, float angle, vec &p);
-extern void particle_splash(int type, int num, int fade, vec &p);
-extern void particle_trail(int type, int fade, vec &from, vec &to);
+extern void particle_splash(int type, int num, int fade, const vec &p);
+extern void particle_trail(int type, int fade, const vec &from, const vec &to);
 extern void particle_emit(int type, int *args, int basetime, int seed, vec &p);
 extern void particle_fireball(int type, vec &o);
-extern void addshotline(dynent *d, vec &from, vec &to);
-extern bool addbullethole(vec &from, vec &to, float radius = 1, bool noisy = true);
+extern void addshotline(dynent *d, const vec &from, const vec &to);
+extern bool addbullethole(const vec &from, const vec &to, float radius = 1, bool noisy = true);
 extern bool addscorchmark(vec &o, float radius = 7);
 
 extern void render_particles(int time, int typemask = ~0);
diff --git a/source/src/renderparticles.cpp b/source/src/renderparticles.cpp
index 0e72267f..a70107f9 100644
--- a/source/src/renderparticles.cpp
+++ b/source/src/renderparticles.cpp
@@ -547,7 +547,7 @@ void particle_flash(int type, float scale, float angle, vec &p)
     newparticle(p, vec(cosf(angle), sinf(angle), scale), 0, type);
 }
 
-void particle_splash(int type, int num, int fade, vec &p)
+void particle_splash(int type, int num, int fade, const vec &p)
 {
     if(parttypes[type].type==PT_BLOOD && !blood) return;
     loopi(num)
@@ -566,7 +566,7 @@ void particle_splash(int type, int num, int fade, vec &p)
     }
 }
 
-void particle_trail(int type, int fade, vec &s, vec &e)
+void particle_trail(int type, int fade, const vec &s, const vec &e)
 {
     vec v;
     float d = e.dist(s, v); 
@@ -590,7 +590,7 @@ VARP(bullethole, 0, 1, 1);
 VARP(bulletholettl, 0, 10000, 30000);
 VARP(bulletbouncesoundrad, 0, 15, 1000);
 
-bool addbullethole(vec &from, vec &to, float radius, bool noisy)
+bool addbullethole(const vec &from, const vec &to, float radius, bool noisy)
 {
     if(!bulletholettl || !bullethole) return false;
     vec surface, ray(to);
@@ -625,7 +625,7 @@ VARP(bulletairsoundrad, 0, 15, 1000);
 VARP(bulletairsoundsourcerad, 0, 8, 1000);
 VARP(bulletairsounddestrad, 0, 8, 1000);
 
-void addshotline(dynent *pl, vec &from, vec &to)
+void addshotline(dynent *pl, const vec &from, const vec &to)
 {
     if(pl == player1 || !shotlinettl || !shotline) return;
     bool fx = shotlinettl > 0 && (player1->isspectating() || !multiplayer(false)); // allow fx only in spect mode and locally
diff --git a/source/src/weapon.cpp b/source/src/weapon.cpp
index 77b3f111..505259e7 100644
--- a/source/src/weapon.cpp
+++ b/source/src/weapon.cpp
@@ -587,7 +587,7 @@ void grenadeent::splash()
     }
 }
 
-void grenadeent::activate(vec &from, vec &to)
+void grenadeent::activate(const vec &from, const vec &to)
 {
     if(nadestate!=NS_NONE) return;
     nadestate = NS_ACTIVATED;
@@ -606,21 +606,27 @@ void grenadeent::_throw(const vec &from, const vec &vel)
 {
     if(nadestate!=NS_ACTIVATED) return;
     nadestate = NS_THROWED;
-
-    this->o = from;
     this->vel = vel;
-    nadestate = NS_THROWED;
-    loopi(10) moveplayer(this, 10, true, 10);
+    this->o = from;
 
     if(local)
     {
         addmsg(SV_THROWNADE, "ri7", int(o.x*DMF), int(o.y*DMF), int(o.z*DMF), int(vel.x*DMF), int(vel.y*DMF), int(vel.z*DMF), lastmillis-millis);
         playsound(S_GRENADETHROW, SP_HIGH);
-        if(!collide(this, false, 0.0f, 0.0f)) destroy();
     }
     else playsound(S_GRENADETHROW, owner);
 }
 
+void grenadeent::moveoutsidebbox(const vec &direction, playerent *boundingbox)
+{
+    vel = direction;
+    o = boundingbox->o;
+    
+    boundingbox->cancollide = false;
+    loopi(10) moveplayer(this, 10, true, 10);
+    boundingbox->cancollide = true;
+}
+
 void grenadeent::destroy() { explode(); }
 bool grenadeent::applyphysics() { return nadestate==NS_THROWED; }
 
@@ -632,7 +638,6 @@ grenades::grenades(playerent *owner) : weapon(owner, GUN_GRENADE), inhandnade(NU
 bool grenades::attack(vec &targ)
 {
     int attackmillis = lastmillis-owner->lastaction;
-    vec &from = owner->o;
     vec &to = targ;
 
     bool waitdone = attackmillis>=gunwait;
@@ -640,7 +645,7 @@ bool grenades::attack(vec &targ)
     switch(state)
     {
         case GST_NONE: 
-            if(waitdone && owner->attacking) activatenade(from, to); // activate
+            if(waitdone && owner->attacking) activatenade(to); // activate
             break;
         
         case GST_INHAND:
@@ -669,15 +674,15 @@ bool grenades::attack(vec &targ)
     return true;
 }
 
-void grenades::attackfx(vec &from, vec &to, int millis) // other player's grenades
+void grenades::attackfx(const vec &from, const vec &to, int millis) // other player's grenades
 {
     throwmillis = lastmillis-millis;
     if(millis == 0) playsound(S_GRENADEPULL, owner); // activate
     else if(millis > 0) // throw
     {
-        inhandnade = new grenadeent(owner, millis);
-        bounceents.add(inhandnade);
-        thrownade(from, to);
+        grenadeent *g = new grenadeent(owner, millis);
+        bounceents.add(g);
+        g->_throw(from, to);
     }
 }
 
@@ -692,7 +697,7 @@ int grenades::modelanim()
     return ANIM_GUN_IDLE;
 }
 
-void grenades::activatenade(vec &from, vec &to)
+void grenades::activatenade(const vec &to)
 {
     if(!mag) return;
     throwmillis = 0;
@@ -703,41 +708,34 @@ void grenades::activatenade(vec &from, vec &to)
     gunwait = info.attackdelay;
     owner->lastattackweapon = this;
     state = GST_INHAND;
-    inhandnade->activate(from, to);
+    inhandnade->activate(owner->o, to);
 }
 
 void grenades::thrownade()
 {
+    if(!inhandnade) return;
     const float speed = cosf(RAD*owner->pitch);
     vec vel(sinf(RAD*owner->yaw)*speed, -cosf(RAD*owner->yaw)*speed, sinf(RAD*owner->pitch));
     vel.mul(1.5f);
-
-    vec from(vel);
-    from.normalize();
-    from.mul(owner->radius+inhandnade->radius);
-    from.mul(1.85f);
-    from.add(owner->o); 
-
-    thrownade(from, vel);
+    thrownade(vel);
 }
 
-void grenades::thrownade(const vec &from, const vec &vel)
+void grenades::thrownade(const vec &vel)
 {
-    if(!inhandnade) return;
-    inhandnade->_throw(from, vel);
+    inhandnade->moveoutsidebbox(vel, owner);
+    inhandnade->_throw(inhandnade->o, vel);
+    inhandnade = NULL;
 
     throwmillis = lastmillis;
     updatelastaction(player1);
     state = GST_THROWING;
-
-    inhandnade = NULL;
     owner->attacking = false;
 }
 
 void grenades::dropnade()
 {
     vec n(0,0,0);
-    thrownade(owner->o, n);
+    thrownade(n);
 }
 
 void grenades::renderstats()
@@ -808,7 +806,7 @@ bool gun::attack(vec &targ)
     return true;
 }
 
-void gun::attackfx(vec &from, vec &to, int millis) 
+void gun::attackfx(const vec &from, const vec &to, int millis) 
 {
     addbullethole(from, to);
     addshotline(owner, from, to);
@@ -832,7 +830,7 @@ bool shotgun::attack(vec &targ)
     return gun::attack(targ);
 }
 
-void shotgun::attackfx(vec &from, vec &to, int millis)
+void shotgun::attackfx(const vec &from, const vec &to, int millis)
 {
     loopi(SGRAYS) particle_splash(0, 5, 200, sg[i]);
     if(addbullethole(from, to))
@@ -856,7 +854,7 @@ bool subgun::selectable() { return weapon::selectable() && !m_noprimary && this
 
 sniperrifle::sniperrifle(playerent *owner) : gun(owner, GUN_SNIPER), scoped(false) {}
 
-void sniperrifle::attackfx(vec &from, vec &to, int millis)
+void sniperrifle::attackfx(const vec &from, const vec &to, int millis)
 {
     addbullethole(from, to);
     addshotline(owner, from, to);
@@ -984,7 +982,7 @@ bool knife::attack(vec &targ)
 int knife::modelanim() { return modelattacking() ? ANIM_GUN_SHOOT : ANIM_GUN_IDLE; };
 
 void knife::drawstats() {}
-void knife::attackfx(vec &from, vec &to, int millis) { attacksound(); }
+void knife::attackfx(const vec &from, const vec &to, int millis) { attacksound(); }
 void knife::renderstats() { };
 
 
diff --git a/source/src/weapon.h b/source/src/weapon.h
index 3e63fa1a..c5f4a756 100644
--- a/source/src/weapon.h
+++ b/source/src/weapon.h
@@ -19,7 +19,7 @@ struct weapon
     int reloading, lastaction;
 
     virtual bool attack(vec &targ) = 0;
-    virtual void attackfx(vec &from, vec &to, int millis) = 0;
+    virtual void attackfx(const vec &from, const vec &to, int millis) = 0;
     virtual void attackphysics(vec &from, vec &to);
     virtual void attacksound();
     virtual bool reload();
@@ -57,11 +57,11 @@ struct grenades : weapon
 
     grenades(playerent *owner);
     bool attack(vec &targ);
-    void attackfx(vec &from, vec &to, int millis);
+    void attackfx(const vec &from, const vec &to, int millis);
     int modelanim();
-    void activatenade(vec &from, vec &to);
+    void activatenade(const vec &to);
     void thrownade();
-    void thrownade(const vec &from, const vec &vel);
+    void thrownade(const vec &vel);
     void dropnade();
     void renderstats();
     bool selectable();
@@ -75,7 +75,7 @@ struct gun : weapon
 {
     gun(playerent *owner, int type);
     virtual bool attack(vec &targ);
-    virtual void attackfx(vec &from, vec &to, int millis);
+    virtual void attackfx(const vec &from, const vec &to, int millis);
     int modelanim();
     void checkautoreload();
 };
@@ -93,7 +93,7 @@ struct sniperrifle : gun
     bool scoped;
 
     sniperrifle(playerent *owner);
-    void attackfx(vec &from, vec &to, int millis);
+    void attackfx(const vec &from, const vec &to, int millis);
     bool reload();
 
     int dynspread();
@@ -112,7 +112,7 @@ struct shotgun : gun
 {
     shotgun(playerent *owner);
     bool attack(vec &targ);
-    void attackfx(vec &from, vec &to, int millis);
+    void attackfx(const vec &from, const vec &to, int millis);
     bool selectable();
 };
 
@@ -160,7 +160,7 @@ struct knife : weapon
     int modelanim();
 
     void drawstats();
-    void attackfx(vec &from, vec &to, int millis);
+    void attackfx(const vec &from, const vec &to, int millis);
     void renderstats();
 };