Hi All
I have a SIG 522 which is failing to fire (occasionally) with Eley Sport ammunition. This batch of Eley Sport works just fine in my other rifles (I bought 1000 rounds of the same batch number).
When I look at the firing pin impressions, they look light to me. This is also the case with other ammunition that doesn't give me any trouble (such as CCI Mini-mag and RWS high velocity).
When I remove the bolt and push the pin from behind as far as it will go, it does not protrude very far from the bolt face. If it was another 1mm longer it would still not break even with the front edge of the bolt.
I took the pin out of the bolt and looked for crud that may have been obstructing the pin at the shoulder, but didn't find anything significant.
These are the possibilities as I see them:
1) get another firing pin made from titanium, 1mm longer at the narrow end.
2) leave the pin as is but increase the rearward roll-pin slot of the firing pin by 1mm in width (this will let the pin go forward an extra mm under inertia).
3) increase the hammer spring tension (I don't want to do this as I don't think it is the problem and it will be really difficult to do).
My gut says (1) is the best option. It should be simple for a gunsmith to make, what say you?
This is the original firing pin, the rifle has had just over 10k rounds through it.
I have a SIG 522 which is failing to fire (occasionally) with Eley Sport ammunition. This batch of Eley Sport works just fine in my other rifles (I bought 1000 rounds of the same batch number).
When I look at the firing pin impressions, they look light to me. This is also the case with other ammunition that doesn't give me any trouble (such as CCI Mini-mag and RWS high velocity).
When I remove the bolt and push the pin from behind as far as it will go, it does not protrude very far from the bolt face. If it was another 1mm longer it would still not break even with the front edge of the bolt.
I took the pin out of the bolt and looked for crud that may have been obstructing the pin at the shoulder, but didn't find anything significant.
These are the possibilities as I see them:
1) get another firing pin made from titanium, 1mm longer at the narrow end.
2) leave the pin as is but increase the rearward roll-pin slot of the firing pin by 1mm in width (this will let the pin go forward an extra mm under inertia).
3) increase the hammer spring tension (I don't want to do this as I don't think it is the problem and it will be really difficult to do).
My gut says (1) is the best option. It should be simple for a gunsmith to make, what say you?
This is the original firing pin, the rifle has had just over 10k rounds through it.