I have followed this for nearly fifty years now, and my preferred source on British gun crime/gun control issues has been Colin Greenwood.
Colin Greenwood, Superintendent, West Yorkshire Metropolitan Police, writing in 1972 about the effects of half a century of UK gun control from the 1920 Firearms Act to the 1968 Firearms Act, in Colin Greenwood, "Firearms Control", (Routledge & Kegan Paul, London, 1972):
"No matter how one approaches the figures, one is forced to the conclusion that the use of firearms in crime was very much less when there were no controls of any sort and when anyone, convicted criminal or lunatic, could buy any type of firearm without restriction. Half a century of strict controls on pistols has ended, perversely, with a far greater use of this class of weapon in crime than ever before."
''Restricting Handguns: The Liberal Skeptics Speak Out'', ed. by Don B. Kates, North River Press, 1979, includes extensive extracts from Colin Greenwood on pages 33 through 55. Colin Greenwood & Joseph Magaddino, "Comparative Cross-Cultural Statistics", in Restricting Handguns p.39 (Don Kates ed., 1979):
At first glance it may seem odd, or even perverse, to suggest that statutory controls on the private ownership of firearms are irrelevant to the problem of armed crime, yet that is precisely what the evidence shows. Armed crime and violent crime generally are products of ethnic and social factors unrelated to the availability of any particular type of weapon. The numbers of firearms required [to arm criminals are minute in comparison to the overall number in private hands], and these are supplied no matter what controls are instituted. Controls have had serious effects on legitimate users of firearms, but there is no case either in the history this country [England] or in the experience of other countries, in which controls have been shown to have restricted the flow of weapons to criminals or in any way to have reduced armed crime.
Comparing the effects of the 1988 restrictions on shotgun certificates, crime statistics before and after the restrictions were imposed, Greenwood concluded "It might be possible to conclude that the law has an immediate effect on the law abiding, but that criminals, by definition, do not obey the law."
British Criminologist Colin Greenwood wrote a critique of the 2006
Home Office Research Study 298, Gun Crime: The market in and use of illegal firearms. He observed:
The 1997 legislation deprived 57,000 people of their property, removed 160,000 handguns from circulation and cost many millions of pounds in compensation. If the effects of that legislation can not be evaluated, then the whole discipline of criminology is a waste of time. If the ban on handguns had any effect in protecting the public, the date on which it came into effect must be reflected in figures for homicide and robbery involving a pistol. The figures for England and Wales for six years before and after 1997 are shown below. .... The pattern of pistol use in homicide is progressively upwards whilst the pattern in robbery shows that the numbers were falling but then rose sharply, only to fall back again. The only conclusion is that the ban imposed by the 1997 Act was simply an irrelevance.
Code:
British Homicides and Armed Robberies
Six years before, 1997 ban, and six years after.
Homicide
Year Total Total Sawn-off
Homicide Firearms Shotgun Shotgun Pistol
1991 725 55 25 7 19
1992 681 56 20 5 28
1993 675 74 29 10 35
1994 727 66 22 14 25
1995 753 70 18 10 39
1996 679 49 9 8 30
1997 753 59 12 4 39
1998 731 49 4 7 32 *
1999 761 62 6 13 42
2000 850 73 12 2 47
2001 858 97 20 1 59
2002 1045 81 20 3 40
2003 858 68 7 4 35
Robberies
Total Total Sawn-off
Year Robbery Firearms Shotgun Shotgun Pistol
1991 45,323 5296 381 650 2988
1992 52,894 5827 406 602 3544
1993 57,845 5918 437 593 3605
1994 60,007 4104 274 373 2390
1995 68,074 3963 235 281 2478
1996 74,035 3617 224 232 2316
1997 63,072 3029 121 178 1854
1998 66,172 2973 138 193 1814 *
1999 84,277 3922 138 217 2561
2000 95,154 4081 98 199 2700
2001 121,375 5323 143 201 3841
2002 108,045 4776 101 174 3332
2003 101,195 4117 98 148 2799
*From 1998 onward the figures are for the financial
year to 1st April of the following year.
Greenwood's complete article at Dunblane resource page:
http://www.dvc.org.uk/dunblane/greenwood.html
I found the outstanding feature of Home Office Research Study 298 is documentation of 1996-2006 rise of a distinct class of British criminals called "armourers" who illegally imported guns, fenced stolen guns, modified guns, repaired guns, used blank-firers or even toys as the basis of zipguns, and kept the British criminal class better armed than before the 1997 handgun ban.
Study 298 also includes interviews with British criminals imprisoned for armed crimes. They told the researchers that they expected they would be able to acquire an illegal weapon within a week of release from prison, pistol, sawn-off shotgun. If they had enough money and wanted one, submachineguns were not hard to find on the British illegal gun market. To achieve this end, the 1997 ban forced the British Olymipic target shooting team to move their handguns to Belgian gun clubs, and cross the English Channel by ferry when they wanted to practice. During that time illegal handguns became a must-have fashion accessory among the British gangster wannabe set aping US gangsta rap and hip-hop cultures.
Looking at the British trends in sawed-shotgun and pistol in homicide and robbery, it appears to me that after the 1996 handgun "adjustment" and the 1997 outright ban, the "armourers" have done a pretty good (bad) job of supplying handguns to illegal users. Use of pistols went up some but use of sawed-off shotguns went down some. Since the sawed-off shotgun is viewed as a substitute for pistols, more availability of illegal pistols should logically lead to less use of sawed-off shotguns.
Another Danger in Comparing International Stats
Apples v Oranges
Colin Greenwood on UK versus International Homicide stats:
Homicide statistics too vary widely. In some developing
countries, the statistics are known to be far from complete. Figures
for crimes labelled as homicide in various countries are simply not
comparable. Since 1967, homicide figures for England and Wales have
been adjusted to exclude any cases which do not result in conviction,
or where the person is not prosecuted on grounds of self defence or
otherwise. This reduces the apparent number of homicides by between 13
per cent and 15 per cent. The adjustment is made only in respect of
figures shown in one part of the Annual Criminal Statistics. In
another part relating to the use of firearms, no adjustment is made. A
table of the number of homicides in which firearms were used in
England and Wales will therefore differ according to which section of
the annual statistics was used as its base. Similarly in statistics
relating to the use of firearms, a homicide will be recorded where the
firearm was used as a blunt instrument, but in the specific homicide
statistics, that case will be shown under "blunt instrument".
Many countries, including the United States, do not adjust
their statistics down in that way and their figures include cases of
self defence, killings by police and justifiable homicides. In
Portugal, cases in which the cause of death is unknown are included in
the homicide figures, inflating the apparent homicide rate very
considerably.
Causing death by dangerous driving is not classed as homicide
in England and Wales, but is classified as homicide in some countries.
Over 200 such cases occur in England and Wales each year.
In France, Switzerland and several other countries, attempts
and completed homicides are treated as a single statistical unit and
can be separated out only by special enquiry.
Past British murder stats are adjusted as cases work their way through the courts and are adjudicated as criminal, justifiable (self-defense) or acquittal. There is no such adjustment in FBI UCR homicide stats. It has been estimated by Gary Kleck that for every US homicide coded in the police crime report as 09C 090C (justifiable homicide) there will be 4 to 7 homicides adjudicated as justifiable (or resulting in acquittal on self-defense grounds) by prosecutor, grand jury, trial jury, trial judge or appellate court adjudicating the evidence as showing self-defense. The FBI UCR does not reflect justifiable homicides adjudicated above the police report level. Any given year, 15 to 20 states do not report 09C on an incident report, even though spot checks show adjudicated justifiable homicides in those states (which are hard to detect because in most US jurisdictions, it appears to me, justifiable homicide is grounds for acquittal, with no adjudication of "justifiable homicide" in the record, just an acquittal on charges of homicide where self-defense is grounds for acquittal.