I use a CZ457 for indoor rimfire benchrest shooting.
As I am only allowed to single load I use a Lowey and/or a CZ single shot adaptor.
When loading the rifle I sit the cartridge down on to the single shot adaptor, ease the cartridge ~1/2 way into the chamber and close the bolt.
This forces the 'C' clip (extractor spring) to open wide as both extractor claws are forced out over the case rim at the same time.
In normal use with a proper magazine the case rim is fed up and behind the claws so this 'double wide' event doesn't happen to the claws/spring.
So eventually my 'C' clip gets a tad stretched/goes 'soft', and doesn't eject the spent case very well.
On another (NZ) forum I asked about heat treating the 'C' clip to get it back to a more normal shape/tension.
This is what I have been told...does it seem right to you gunsmith guys? Firstly squeeze the 'C' clip inwards a bit to get it more like an original 'C' clip in shape/tension and then...
"When you are happy with the tension after bending then bring it to a full cherry red on a piece of flat steel by heating under the steel then allow to air cool. It is now fully annealed. Repeat the performance to cherry red and flick the spring into a can of engine oil. It is now dead hard and brittle so be careful. Polish the spring to a bright finish with fine wet & dry paper and replace on the steel plate and gently reheat the plate until the spring is a nice blue colour, then flick back into oil. You now have a spring which will hold tension. The secret to refitting the springs to avoid straining them is to get one leg in the correct position then carefully ease the spring into place over the other side using a small thin bladed screwdriver".
Your thoughts?
I am lucky enough to have a few spare new extractor springs and claws now but one day when the supply runs out I'd like to be ready.
Thanks.
As I am only allowed to single load I use a Lowey and/or a CZ single shot adaptor.
When loading the rifle I sit the cartridge down on to the single shot adaptor, ease the cartridge ~1/2 way into the chamber and close the bolt.
This forces the 'C' clip (extractor spring) to open wide as both extractor claws are forced out over the case rim at the same time.
In normal use with a proper magazine the case rim is fed up and behind the claws so this 'double wide' event doesn't happen to the claws/spring.
So eventually my 'C' clip gets a tad stretched/goes 'soft', and doesn't eject the spent case very well.
On another (NZ) forum I asked about heat treating the 'C' clip to get it back to a more normal shape/tension.
This is what I have been told...does it seem right to you gunsmith guys? Firstly squeeze the 'C' clip inwards a bit to get it more like an original 'C' clip in shape/tension and then...
"When you are happy with the tension after bending then bring it to a full cherry red on a piece of flat steel by heating under the steel then allow to air cool. It is now fully annealed. Repeat the performance to cherry red and flick the spring into a can of engine oil. It is now dead hard and brittle so be careful. Polish the spring to a bright finish with fine wet & dry paper and replace on the steel plate and gently reheat the plate until the spring is a nice blue colour, then flick back into oil. You now have a spring which will hold tension. The secret to refitting the springs to avoid straining them is to get one leg in the correct position then carefully ease the spring into place over the other side using a small thin bladed screwdriver".
Your thoughts?
I am lucky enough to have a few spare new extractor springs and claws now but one day when the supply runs out I'd like to be ready.
Thanks.
