BSA No4 Sporting rifle PICS ADDED

Since you said the barrel is marked with a broad arrow, here's an easy way to check if it's .308 or not.  Military .308 barrels (both the hammer-forged ones and the latter lathed ones) are marked "CR1470" on the knox form.

I'm not sure on the legalities of this in the UK, but here in the US you could probably just swap out the 10-round .308 for a 10-round .303 (addding a few dollars to make up the difference in value as the .308 mags are rarer, here at least, than the .308 ones.)

There should be no problem sending a magazine to the USA parcel post as it's not cla$sed as an offensive weapon. 303 magazines are easily obtained in the UK but shop around, some of the gun dealers prices are a joke!

how much for the L4 magazine??
last one I purchased through Enfield and it cost me 5poundsUK plus postage

Finally got the rifle out on the range today.

The groups weren't too good 4-6 inches at 100m. This was using South African Mk7 ball from 1961. I noticed eventually that the scope mounts had some significant movement and stopping that seems to improve things but it came loose again. It's a rubber armoured chinese scope - trade name Leapers - I think that will need replaced. The trigger feels clunky and will need smoothing somehow I think. The scope mount is by Parker Hale and is fixed to what I believe are the mountings for the original rear sight. It seems to be a P-H BA21.

The rifle has the receiver markings:
No4 Mk1/2 (F) FTR
/ 54 BY15270 ( this number appears elsewhere and so I assume it is the serial number)

The 10 round magazine is indeed a 7.62 and has the markings: CR1256 1965 on the follower and CR 141A  and 65 on the case. The flush fitting 303 mag is fine but I noticed a few misfeeds which seemed to be caused by rounds coming off the follower at a steep angle and missing the chamber.

Fired about 40 rounds, my shoulder knows it's been to the range I can tell you!
It was nice to a have a pop with my Ruger 223 as well, the accuracy of the Ruger re-assured me that I was still shooting straight

I think I will eventually get a nice No 4 in the original state, they are an iconic rifle. This one was converted at a time when the originals were ten a penny. At least its a classic British conversion and not a nasty bubba-job 

An Ishapore 7.62 magazine wouldn't fit a No4 even in 7.62, surely.

This 5-round magazine has issues. The 5th round exits the magazine at a very steep angle. Instead of entering the chamber, the point of the round lodges in the upper, front corner of the breech. Very irritating - any thoughts?