Odd 'step' in the bore?

[mrclark303]

Hi all,

A bit of a quandary....

One of my L1A1's UK spec Straight pull, has a slightly odd issue in the bore.
I popped my cheap bore viewer down it yesterday and as the camera proceeded down the bore, about 6 inches from the chamber, a bright 'ring' came into view.

I have had this rifle for over 10 years and put hundred of rounds down range with it, probably about a 1000, without any issues.

There is absolutely no evidence of it with the MK1 eyeball....

These is no bulge in that area, no obvious issue in the exterior of the barrel, just this tiny raised, perfectly circular ring. You can just feel the slightest of resistance as the camera rides over it.

The low resolution of the bore viewer prevents a really good look at it.

This rifle happened to be the very first UK assembled Section 1 compliant L1A1, completed and proofed in 2009. As no new L1A1 Barrels were available then, the barrel was (allegedly) a machined .30 Cal M1919 N.O.S barrel.

I don't know if this is correct, but it is four grove left hand twist and the M1919 barrel certainly has more than enough meat and length to profile an L1A1 barrel from.

So it's certainly plausible.

Is this slight ring a simple wartime expediency measure?

Hypothetically speaking, were long lengths of M1919 barrel Bored, rifled, cut and profiled, with this ring simply part of where the cutter was replaced on the production line?

Was the 'ring' some obscure part of the function or design of the M1919, slight increase in back pressure to aid its operation, etc, etc??

Or am I about to get a hook for a left hand??

I obviously won't be shooting her again until I am sure she's safe to shoot

All opinions welcome guys....