A British empire made rifle used during WW1, WW2 and still to be found & used in many, many countries. A very well made & dependable bolt action rifle with a 10 round magazine.
303 was the .303 inch diameter bullet that was fired by the Short Magazine Lee Enfield- or SMLE. Standard rifle of the British military from 1907 to the1960s, and still in limited use today.
A sporterised Lithgow .303 SMLE
Google the phrase and you will get hundreds of hits.
A SPORTERISED SMLE .303 RIFLE WITH A THUMHOLE STOCK.
Bren gun, Lewis gun, SMLE rifle
2441 feet per second when fired from the British SMLE rifle. Velocity will vary when fired from rifles with a longer or shorter barrel.
An SMLE rifle comes in three types: SMLE Mk III - 1132mm / 44.57" SMLE No. 4 Mk 1 - 1129mm / 44.45" SMLE No. 5 "Jungle Carbine" - 1003mm / 39.49"
Gunsmiths, gun shows, and on-line sources such as gunpartscorp.com, and brownells.com. You will need to know which model .303 you have. If you do not know, visit surplusrifle.com, and check Enfield and SMLE.
The Lee-Enfield .303 Mk.1 and other variants to the SMLE Mk.III.
The Ross .303 rifle was initially issued to Canadian troops during World War 1. It was highly accurate, but due to its unreliability it was unsuitable for use in the muck and grime of the trenches and so was retained only by snipers and marksman. The rest of Canadian forces were reissued with the Lee-Enfield .303 SMLE.
The MLE entered production in 1895, and ceased production in 1907, when the SMLE was introduced. Most countries manufacturing SMLE rifles ceased after 1945, as they had a glut of surplus rifles following the war, but some countries continued making them. The last country to mass produce the .303 calibre rifles was India, with their production ceasing ~1960.
Assuming you mean a British MILITARY rifle, such as the SMLE, between $100-$350, depending on condition and originality. Rifles that have been "sporterized" lose much of their value as a collector's item.