Prnter is reducing items photocopied to A5 from A4

Sounds like you are trying to convince the machine to print a document on to paper half the size required without telling the machine to reduce or scale the document to fit the target paper

Check in the users manual, which you can download from http://support.brother.com/g/b/manuallist.aspx?c=gb&lang=en&prod=mfc7460dn_all&flang=English&type3=440&type2=5

The problem is with the "Automatic Paper Size Sensor" / APS sensors, which are located near LENS / CCD UNIT, under the platen glass.If you can open and remove the platen glass by yourself then open it and clean the APS sensors with soft cloth damped with alcohol. If the problem is still there, then please go to the service mode of your photocopier machine.
(Press "Utility/Counter"
then
press "Check Details" > STOP > 0 > 0 > STOP > 0 > 1, for service mode)
When you are in service mode then go to "System 1" and then into "Marketing Area" , When you are in this option, select marketing area "US" and then press "OK" . Now exit from the service mode and place A4 original on platen glass and check the size showing in the display.
Do not worry whatever size is showing, you will get your complete copy.Now press start button to make copies. When you will make a copy you will get your complete print out.No print area will be missing.
Best of Luck!

first remove all paper trays and inspect for paper behind the tray area and inside the machine
second verify if the paper trays are set to the correct paper sizes this is easy just look at the screen under paper trays and all trays should tell you what they are set to

The paper you have inserted into the printer, and your page size settings have to match. You can't load A4 paper and tell it to print A5 size. This is why it is printing so small on the A4 paper. It assumes you need to trim it down to A5 size after printing.

It can only enlarge smaller sizes ( like A5 ) to maximum size of A4.

Around the lcd panel is located reduce enlarge button, press one time for auto sizes or twice so that you can regulate in steps of 1%

Hi,
Click on the File tab which is present in top left corner of the file, Click on Page Setup, a separate window appears, there on paper menu you can see a Size which is a drop down box. Drop down the size and select A5 and press ok. Now onwards it prints in A5 size. Later you can change it any size. Thank you........

Usually if you see the page in the Publisher window is already landscape, it will go landscape in the Printpreview and also in the print out. I just try to imagine what is your problem.
If I am not mistaken, this is what you did:
You have two "small" pages (maybe A5??) and you want to print it in one page of A4. Of course the A4 should be landscape.
Publisher does not have the facility to set 2 pages A5 in one A4 like in Microsoft Word.
The easiest way is just create a new page with A4, then copy the 2 pages (or you called it flyers) and paste it in that A4 landscape page.
Publisher can do print 2 pages A5 in one sheet A4 but the arrangement is as booklet. You can see the choices in File --> Page Setup --> tab "Layout" --> scroll the Publication type.
I do print 2 pages A5 in one sheet with many variations using addition software named "Clickbook".
Let me know if I m wrong in interpret your problem.

This machine will only print certain sizes as borderless. A5 is not one of them. You can use the following media with this feature: Matte Paper - Heavyweight: A4, Letter Premium Glossy Photo Paper:A4, Letter, 5 x 7", 10 x 15 cm/4 x 6", 8 x 10" Photo Paper:A4 Premium Semigloss Photo Paper:A4, Letter, 10 x 15 cm/4 x 6" Glossy Photo Paper:Letter, 10 x 15 cm/4 x 6" As you can see A5 is not in the list, therefor you will not be able to print A5 borderless via the normal means.