-
Legacy Member
Stock installation No1 Mk III*
I just received a new stock for My SMLE No 1 Mk III*, is the procedure for fitting the stock similar to that described in Mr Laidler's article for the No 4 rifle? I have looked for instructions specific to the No 1,without alot of sucess.
Thanks
Information
|
Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current. |
|
-
-
10-18-2013 08:06 PM
# ADS
Friends and Sponsors
-
-
-
-
Legacy Member
Basic principles are the same, HOWEVER........
A "standard" barrel in a Mklll* has specific bedding requirements. These MUST be adhered to if you want the thing to perform with MkVlll ball (assuming you can find any).
The key "tricks" are in the "upwards" and "downwards" pressure on the barrel.
In order to "tune" the rifle to the ammo, as is the practice in ordnance systems, the engineers did a couple of things:
The "Band, inner", i.e., the one with a small threaded lug that is fitted around a standard barrel, is part of a system supposed to pull the barrel down towards the fore end. Note that, it is not just a matter of "wind the screw in until it squeaks"; the inner band came with a special screw, spring and washer, to ensure the right amount of static load AND a bit of "give" during firing. It has a small, but important "damping" function.
Towards the muzzle end , there is a small but strong spring and a plunger fitted between the nose cap and the barrel. This provides UPWARDS pressure in the barrel at that point. Now, have a look at the nose cap. At the top of the "barrel hole" is a small extra cut-out a few millimetres wide. The bottom CORNERS of this tiny extra "window" are the bearing points for the barrel. The pressure provided by the spring and plunger (actually called the STUD), inside the nose cap, causes the muzzle to rise and contact the two lower corners of this little "window" above said "barrel hole".
This combination of upward pressure from the spring and stud and the corners of that tiny window does a couple of things:
Centres the barrel.
Causes it to return to a constant location after each shot.
Provides a "damping" function.
James Sweet's book has a discussion about barrel vibration and the location of nodes, etc.
Bear in mind that a lot of research and considerable ammo consumption went into "fiddling" with the barrel bedding on the SMLE. When the system changed from the old, slow, Mk6 round-nosed ammo to the slinky Mk7 bullet, a lot of things had to be re-thought.
The massive change in the trajectory required the rear sight to be redesigned.
The shape of the bullet required a whole new magazine design.
The vibration and "wave" patterns in the barrel that resulted from launching this slinky new, high velocity bullet had to be dealt with, hence the subtle but effective application of pressure to the barrel by the inner band and the nose cap.
But, just to make it interesting, the "new" set-up had to be able to still run with Mk6 ammo in an "emergency", hence the long throat formed forward of the cartridge chamber. This interesting feature was retained well into the 1930s.
-
The Following 4 Members Say Thank You to Bruce_in_Oz For This Useful Post: