Mk I sight swinging on the leaf

[Peter Laidler]

I used to No4T's with between 3 to 5 lbs and see how they grouped. Vertically strung shots, increase the weight but never more than 7 lbs

[bow]

Thanks. i test muuzle pressure about 2" in fore end toward the knox form, where it should contact the barrel. in fact, in manuals it is said " barrel must contact fore-end for at least two inches" so i check the prssure required to lift the barrel two inches backward in fore end. Is it right ?

[Thunderbox]

Anyone got a diagram to hand?

Bow, its the pressure to lift the barrel vertically up off the wood at the front of the forend & barrel - where the forend has a metal cap.

[bow]

I apply pressure at the muzzle and a little paper shim between barrel and fore end where the fore end metal cap ends. When the shims moves , i check the poundage.

[Peter Laidler]

That's a reasonable check Bow but we just use a calibrated spriung balance/trigger tester and 'feel' to test for the point of lift. Just comes with experience. TRhe main point is that thge barrel MUST be damped but not muzzle bound.

[bow]

Done.

[newcastle]

soryr quick question. the barrel must be damped by contact with eth forend (underneath) or teh handguard. I ASSUME the foreend buit want to check 100%. Maybe this is why there was a thing cork sheet under the muzzle of one of my No.4s?

[Thunderbox]

The barrel is damped by being in contact with the front part of the forend - the dark patch on the raised part of the barrel channel where the forend cap is.

The down-pressure has to be achieved by "tilting" the whole barrel and receiver forwards and down in the forend. This means that the barrel pressure is supposed to be adjusted by relieving under the reinforce and the front part of the receiver bedding - so that you get both good down-pressure and good bedding at the receiver end.

Some people use a short cut of instead padding under the barrel. This is also used where someone has taken the original lump out of the front part barrel channel (ie for centre bedding), or where the forend is too warped in a vertical direction to be able to adjust the barrel and receiver fit sufficiently.

The barrel should be free to move upwards in the barrel channel without being held or obstructed by the top hand guards. The barrel usually needs at least 1/8" free vertical movement.