diff --git a/language.version b/language.version
index 8dab43984..a054fce78 100644
--- a/language.version
+++ b/language.version
@@ -1,3 +1,3 @@
 [default]
-SWWM_MODVER="\chSWWM \czGZ\c- \cw0.9.11b-pre r518 \cu(Mon 31 May 16:23:12 CEST 2021)\c-";
-SWWM_SHORTVER="\cw0.9.11b-pre r518 \cu(2021-05-31 16:23:12)\c-";
+SWWM_MODVER="\chSWWM \czGZ\c- \cw0.9.11b-pre r519 \cu(Tue  1 Jun 16:51:13 CEST 2021)\c-";
+SWWM_SHORTVER="\cw0.9.11b-pre r519 \cu(2021-06-01 16:51:13)\c-";
diff --git a/zscript/weapons/swwm_baseweapon_precisechair.zsc b/zscript/weapons/swwm_baseweapon_precisechair.zsc
index d64fe5865..d60fa90c7 100644
--- a/zscript/weapons/swwm_baseweapon_precisechair.zsc
+++ b/zscript/weapons/swwm_baseweapon_precisechair.zsc
@@ -28,7 +28,7 @@ extend Class SWWMWeapon
 	ui Vector3 cpos;
 	ui Color ccol;
 	ui Vector2 lagvpos;
-	transient ui uint prevms;
+	transient ui double prevframe;
 
 	override void DoEffect()
 	{
@@ -48,7 +48,7 @@ extend Class SWWMWeapon
 		{
 			SWWMWeapon(Owner.player.PendingWeapon).cpos = cpos;
 			SWWMWeapon(Owner.player.PendingWeapon).lagvpos = lagvpos;
-			SWWMWeapon(Owner.player.PendingWeapon).prevms = prevms;
+			SWWMWeapon(Owner.player.PendingWeapon).prevframe = prevframe;
 		}
 	}
 	// extra drawing, usually scopes
@@ -67,11 +67,11 @@ extend Class SWWMWeapon
 		Vector3 ndc = SWWMUtility.ProjectPoint(sb.projdata,e.ViewPos+tdir);
 		if ( ndc.z >= 1. ) return;
 		Vector2 vpos = SWWMUtility.NDCToViewport(sb.projdata,ndc);
-		double frametime = (MSTime()-prevms)/1000.;
-		double theta = clamp(15.*frametime,0.,1.); // naive, but whatever
-		if ( !prevms || (lagvpos == (0,0)) ) lagvpos = vpos;
+		double frametime = ((gametic+e.fractic)-prevframe)/GameTicRate;
+		double theta = clamp(30.*frametime,0.,1.); // naive, but whatever
+		if ( !prevframe || (lagvpos == (0,0)) ) lagvpos = vpos;
 		else lagvpos = lagvpos*(1.-theta)+vpos*theta;
-		prevms = MSTime();
+		prevframe = gametic+e.fractic;
 		int cnum = abs(CVar.FindCVar('crosshair').GetInt());
 		if ( !cnum ) return;
 		String tn = String.Format("XHAIR%s%d",(Screen.GetWidth()<640)?"S":"B",cnum);
diff --git a/zscript/weapons/swwm_cbt.zsc b/zscript/weapons/swwm_cbt.zsc
index 7eb66c387..f56ffbc2a 100644
--- a/zscript/weapons/swwm_cbt.zsc
+++ b/zscript/weapons/swwm_cbt.zsc
@@ -161,9 +161,9 @@ Class Wallbuster : SWWMWeapon
 		Vector3 ndc = SWWMUtility.ProjectPoint(sb.projdata,e.ViewPos+tdir);
 		if ( ndc.z >= 1. ) return;
 		Vector2 vpos = SWWMUtility.NDCToViewport(sb.projdata,ndc);
-		double frametime = (MSTime()-prevms)/1000.;
-		double theta = clamp(15.*frametime,0.,1.); // naive, but whatever
-		if ( !prevms || (lagvpos == (0,0)) ) lagvpos = vpos;
+		double frametime = ((gametic+e.fractic)-prevframe)/GameTicRate;
+		double theta = clamp(30.*frametime,0.,1.); // naive, but whatever
+		if ( !prevframe || (lagvpos == (0,0)) ) lagvpos = vpos;
 		else lagvpos = lagvpos*(1.-theta)+vpos*theta;
 		for ( int i=0; i<25; i++ )
 		{
@@ -173,11 +173,11 @@ Class Wallbuster : SWWMWeapon
 			ndc = SWWMUtility.ProjectPoint(sb.projdata,e.ViewPos+tdir);
 			if ( ndc.z >= 1. ) return;
 			vpos = SWWMUtility.NDCToViewport(sb.projdata,ndc);
-			if ( !prevms || (lagvpos25[i] == (0,0)) ) lagvpos25[i] = vpos;
+			if ( !prevframe || (lagvpos25[i] == (0,0)) ) lagvpos25[i] = vpos;
 			else lagvpos25[i] = lagvpos25[i]*(1.-theta)+vpos*theta;
 			Screen.DrawTexture(ctex,false,int(lagvpos25[i].x),int(lagvpos25[i].y),DTA_DestWidthF,ts.x*sz,DTA_DestHeightF,ts.y*sz,DTA_AlphaChannel,true,DTA_FillColor,ccol25[i]);
 		}
-		prevms = MSTime();
+		prevframe = gametic+e.fractic;
 	}
 
 	ui Vector3, Color TraceForCrosshair25( int i )
diff --git a/zscript/weapons/swwm_splode.zsc b/zscript/weapons/swwm_splode.zsc
index 6e8610341..9b54db3f1 100644
--- a/zscript/weapons/swwm_splode.zsc
+++ b/zscript/weapons/swwm_splode.zsc
@@ -517,7 +517,7 @@ Class DualExplodiumGun : SWWMWeapon
 		{
 			SWWMWeapon(Owner.player.PendingWeapon).cpos = sw.cpos;
 			SWWMWeapon(Owner.player.PendingWeapon).lagvpos = sw.lagvpos;
-			SWWMWeapon(Owner.player.PendingWeapon).prevms = sw.prevms;
+			SWWMWeapon(Owner.player.PendingWeapon).prevframe = sw.prevframe;
 		}
 		[sw.cpos, sw.ccol] = sw.TraceForCrosshair();
 	}