diff --git a/SimG4CMS/Calo/interface/HFShowerLibrary.h b/SimG4CMS/Calo/interface/HFShowerLibrary.h
index db985ff681c83..4b6ee7205a5ab 100644
--- a/SimG4CMS/Calo/interface/HFShowerLibrary.h
+++ b/SimG4CMS/Calo/interface/HFShowerLibrary.h
@@ -67,7 +67,7 @@ class HFShowerLibrary {
   TFile *             hf;
   TBranch             *emBranch, *hadBranch;
 
-  bool                verbose, applyFidCut, newForm;
+  bool                verbose, applyFidCut, newForm, v3version;
   int                 nMomBin, totEvents, evtPerBin;
   float               libVers, listVersion; 
   std::vector<double> pmom;
diff --git a/SimG4CMS/Calo/src/HFShowerLibrary.cc b/SimG4CMS/Calo/src/HFShowerLibrary.cc
index e217e7e6da010..0485fcb1140c4 100644
--- a/SimG4CMS/Calo/src/HFShowerLibrary.cc
+++ b/SimG4CMS/Calo/src/HFShowerLibrary.cc
@@ -98,6 +98,13 @@ HFShowerLibrary::HFShowerLibrary(std::string & name, const DDCompactView & cpv,
   nameBr           = branchPre + hadName + branchPost;
   hadBranch        = event->GetBranch(nameBr.c_str());
   if (verbose) hadBranch->Print();
+
+  v3version=false;
+  if ( emBranch->GetClassName() == std::string("vector<float>") ) {
+    v3version=true;
+  }
+  
+
   edm::LogInfo("HFShower") << "HFShowerLibrary:Branch " << emName 
 			   << " has " << emBranch->GetEntries() 
 			   << " entries and Branch " << hadName 
@@ -118,9 +125,9 @@ HFShowerLibrary::HFShowerLibrary(std::string & name, const DDCompactView & cpv,
 }
 
 HFShowerLibrary::~HFShowerLibrary() {
-  if (hf) { hf->Close(); }
-  delete fibre;
-  delete photo;
+  if (hf)     hf->Close();
+  if (fibre)  delete   fibre;  fibre  = 0;
+  if (photo)  delete photo;
 }
 
 void HFShowerLibrary::initRun(G4ParticleTable * theParticleTable,
@@ -372,11 +379,14 @@ std::vector<HFShowerLibrary::Hit> HFShowerLibrary::fillHits(G4ThreeVector & hitP
   if (nHit > npe && !onlyLong)
     edm::LogWarning("HFShower") << "HFShowerLibrary: Hit buffer " << npe 
 				<< " smaller than " << nHit << " Hits";
-  return hit;
+ return hit;
+
 }
 
 bool HFShowerLibrary::rInside(double r) {
-  return (r >= rMin && r <= rMax);
+
+  if (r >= rMin && r <= rMax) return true;
+  else                        return false;
 }
 
 void HFShowerLibrary::getRecord(int type, int record) {
@@ -386,19 +396,46 @@ void HFShowerLibrary::getRecord(int type, int record) {
   photo->clear();
   if (type > 0) {
     if (newForm) {
-      hadBranch->SetAddress(&photo);
-      hadBranch->GetEntry(nrc+totEvents);
+      if ( !v3version ) {
+	hadBranch->SetAddress(&photo);
+	hadBranch->GetEntry(nrc+totEvents);
+      }
+      else{
+	std::vector<float> t;
+	std::vector<float> *tp=&t;
+	hadBranch->SetAddress(&tp);
+	hadBranch->GetEntry(nrc+totEvents);
+	unsigned int tSize=t.size()/5;
+	photo->reserve(tSize);
+	for ( unsigned int i=0; i<tSize; i++ ) {
+	  photo->push_back( HFShowerPhoton( t[i], t[1*tSize+i], t[2*tSize+i], t[3*tSize+i], t[4*tSize+i] ) );
+	}
+      }
     } else {
       hadBranch->SetAddress(&photon);
       hadBranch->GetEntry(nrc);
     }
   } else {
     if (newForm) {
-      emBranch->SetAddress(&photo);
+      if (!v3version) {
+	emBranch->SetAddress(&photo);
+	emBranch->GetEntry(nrc);
+      }
+      else{
+	std::vector<float> t;
+	std::vector<float> *tp=&t;
+	emBranch->SetAddress(&tp);
+	emBranch->GetEntry(nrc);
+	unsigned int tSize=t.size()/5;
+	photo->reserve(tSize);
+	for ( unsigned int i=0; i<tSize; i++ ) {
+	  photo->push_back( HFShowerPhoton( t[i], t[1*tSize+i], t[2*tSize+i], t[3*tSize+i], t[4*tSize+i] ) );
+	}
+      }
     } else {
       emBranch->SetAddress(&photon);
+      emBranch->GetEntry(nrc);
     }
-    emBranch->GetEntry(nrc);
   }
 #ifdef DebugLog
   int nPhoton = (newForm) ? photo->size() : photon.size();
@@ -436,9 +473,8 @@ void HFShowerLibrary::loadEventInfo(TBranch* branch) {
     listVersion = 3.6;
     pmom        = {2,3,5,7,10,15,20,30,50,75,100,150,250,350,500,1000};
   }
-  for (int i=0; i<nMomBin; i++) {
+  for (int i=0; i<nMomBin; i++) 
     pmom[i] *= GeV;
-  }
 }
 
 void HFShowerLibrary::interpolate(int type, double pin) {
@@ -448,7 +484,7 @@ void HFShowerLibrary::interpolate(int type, double pin) {
 		       << " GeV with " << nMomBin << " momentum bins and " 
 		       << evtPerBin << " entries/bin -- total " << totEvents;
 #endif
-  int irc[2] = {0, 0};
+  int irc[2]={0,0};
   double w = 0.;
   double r = G4UniformRand();
 
diff --git a/SimG4CMS/Calo/test/convertHFShowerLibrary.C b/SimG4CMS/Calo/test/convertHFShowerLibrary.C
new file mode 100644
index 0000000000000..5fa22ae5c93d4
--- /dev/null
+++ b/SimG4CMS/Calo/test/convertHFShowerLibrary.C
@@ -0,0 +1,65 @@
+#include "TFile.h"
+#include "TTree.h"
+#include "TTreeReader.h"
+#include "TTreeReaderArray.h"
+#include <vector>
+
+// takes "new" form of HF shower library and makes it a v3 version
+
+void convertHFShowerLibrary() {
+  TFile *nF=new TFile("david.root","RECREATE","hiThere",1);
+  TTree *nT=new TTree("HFSimHits","HF simple tree");
+  std::vector<float> *parts=new std::vector<float>();
+  std::vector<float> *partsHad=new std::vector<float>();
+  nT->Branch("emParticles", &parts);
+  nT->GetBranch("emParticles")->SetBasketSize(1);
+  nT->Branch("hadParticles", &partsHad);
+  nT->GetBranch("hadParticles")->SetBasketSize(1);
+
+  TDirectory *target=gDirectory;
+  TFile *oF=TFile::Open("HFShowerLibrary_npmt_noatt_eta4_16en_v3_orig.root");
+  TTree *t=(TTree*)oF->Get("HFSimHits");
+  TTreeReader fReader(t);
+  TTreeReaderArray<Float_t> b1(fReader, "emParticles.position_.fCoordinates.fX");
+  TTreeReaderArray<Float_t> b2(fReader, "emParticles.position_.fCoordinates.fY");
+  TTreeReaderArray<Float_t> b3(fReader, "emParticles.position_.fCoordinates.fZ");
+  TTreeReaderArray<Float_t> b4(fReader, "emParticles.lambda_");
+  TTreeReaderArray<Float_t> b5(fReader, "emParticles.time_");
+
+  TTreeReaderArray<Float_t> h1(fReader, "hadParticles.position_.fCoordinates.fX");
+  TTreeReaderArray<Float_t> h2(fReader, "hadParticles.position_.fCoordinates.fY");
+  TTreeReaderArray<Float_t> h3(fReader, "hadParticles.position_.fCoordinates.fZ");
+  TTreeReaderArray<Float_t> h4(fReader, "hadParticles.lambda_");
+  TTreeReaderArray<Float_t> h5(fReader, "hadParticles.time_");
+
+
+  target->cd();
+  while ( fReader.Next() ) {
+    parts->clear();
+    unsigned int s=b1.GetSize();
+    parts->resize(5*s);
+    for ( unsigned int i=0; i<b1.GetSize(); i++) {
+      (*parts)[i]=(b1[i]);
+      (*parts)[i+1*s]=(b2[i]);
+      (*parts)[i+2*s]=(b3[i]);
+      (*parts)[i+3*s]=(b4[i]);
+      (*parts)[i+4*s]=(b5[i]);
+    }  
+
+    partsHad->clear();
+    s=h1.GetSize();
+    partsHad->resize(5*s);
+    for ( unsigned int i=0; i<h1.GetSize(); i++) {
+      (*partsHad)[i]=(h1[i]);
+      (*partsHad)[i+1*s]=(h2[i]);
+      (*partsHad)[i+2*s]=(h3[i]);
+      (*partsHad)[i+3*s]=(h4[i]);
+      (*partsHad)[i+4*s]=(h5[i]);
+    }  
+
+    nT->Fill();
+  }
+
+  nT->Write();
+  nF->Close();
+}
diff --git a/SimG4Core/Application/python/g4SimHits_cfi.py b/SimG4Core/Application/python/g4SimHits_cfi.py
index d85fcff47c1d1..13914f05be488 100644
--- a/SimG4Core/Application/python/g4SimHits_cfi.py
+++ b/SimG4Core/Application/python/g4SimHits_cfi.py
@@ -461,4 +461,4 @@
 ## Change the HFShowerLibrary file used for Run 2
 ##
 from Configuration.Eras.Modifier_run2_common_cff import run2_common
-run2_common.toModify( g4SimHits.HFShowerLibrary, FileName = 'SimG4CMS/Calo/data/HFShowerLibrary_npmt_noatt_eta4_16en_v3.root' )
+run2_common.toModify( g4SimHits.HFShowerLibrary, FileName = 'SimG4CMS/Calo/data/HFShowerLibrary_npmt_noatt_eta4_16en_v4.root' )