r u talking about the trimmable shims? do they come in metal or don't I torque it down that much? Anyone know the going price of asbestos packing for vickers barrels (et al)?
thanks for the info folks.
I'm a bit unsure of what the question is but here's what Dolf has in his book:
Testing the length of the connecting rod:
The following instructions from a British Armourer's manual describe how to test and adjust the headspace adjustment:
1. Remove the fusee spring.
2. Raise the rear cover and put the crank handle onto the roller.
3. Insert on the face of the extractor, opposite to the firing pin hole, an armourer’s dummy (headspace gauge).
4. lift the extractor up to its highest point.
5. See that the barrel is fully forward.
6. Turn the crank handle towards the check lever.
7. Guide the armourer 's dummy into the chamber.
8. Push the check lever back just clear of the crank handle, and let the crank handle gently down towards it.
9. If the connecting rod is of correct length, a check will be felt just before the crank handle reaches the check lever. If no check is felt, the lock is not fully home and the connecting rod is too short.
Adjusting the length of the connecting rod:
1. Remove the fusee spring.
2. Take out the lock.
3. Determine the number of No 1 or of No 2 washers (or both) required to correct the length of the connecting rod, by first placing a No 1 on the outer face of the adjusting nut on the connecting rod, replacing the lock and re-testing the length, adding washers and again re-testing. When the rod’s length has been determined, the washers which have been placed on the outer face of the adjusting nut must be assembled permanently on the shoulder of the connecting rod and secured by the nut. To do this, turn the connecting rod back, unscrew the adjusting nut with the combination tool and remove it. Place the washers on the connecting rod and screw the adjusting nut tightly home onto the washers. Retest to ensure that the adjustment is correct
Note; two sizes of washers, .003- and .005-in, are issued. The No 1, .003-in washer has one hole punched in the rim and the No 2, .005-in washer has two holes in the rim. By the use of these sizes in combination, adjustments to 3, 5, 6, 8, 9, and 10 thousandths of an inch can be made.
The barrel groove and muzzle gland packing must be tight enough to prevent leakage, but if too much string is wound around the muzzle and the gland is screwed down tightly, the barrel will not be able to move. To rectify this, loosen the gland until the recoiling parts can move, then gradually tighten. If it cannot, after a few turns, be screwed down without clamping the barrel, remove some of the packing material. There should be some resistance on the last few turns when tightening the gland, otherwise there will not be a good seal.
To pack the barrel groove, packing string similar to the old type water pump packing is most commonly used, but modern PVC pump packing and even rubber “O” rings of suitable size can be used. The old type string should be lubricated, then wound around the barrel groove two or three times. The more material that can be inserted in this groove and still allow the barrel to reciprocate the better, as the seal will be improved and water will not leak out
A "rule of thumb" indicated that a length of British issue string of twice the circumference of the water jacket should be used for the front packing, and a length of 1 1/2 times the length of the water jacket should be used for the rear cannelure. Note the string must be lubricated so the barrel will slide, the rear cannelure packing must be oiled after inserting it, and then tapped down so the groove is comple