MisterEddy
02-01-2014, 02:25 PM
Ever since I bought my WSM Savage 110 short action, I had been disappointed with the operation of the bolt. This was one of the earlier staggered feed models with the CRF bolt head. If you have one of these then you are familiar with what they look like, but here is a visual:
http://i.imgur.com/sBKgAQU.jpg
The stock bolt body has fairly poor tolerances, so I thought that I would get a PTG bolt body to help tighten this up and minimize binding while working the bolt. So I installed one with larger diameter and lapped it to the receiver, which did improve the bolt operation significantly. However, I was still not happy with the bolt operation, and I began to suspect the ejector was the cause of this. When working the bolt with the action out of the stock, I realized what the problem was.
The CRF savage action has a standing ejector that mounts on the trigger group pin and sits in a machined slot in the receiver and also a matching slot in the bolt head. Here is what I am talking about:
http://i.imgur.com/fiUOjS0.jpg
http://i.imgur.com/qhRYWIt.jpg
http://i.imgur.com/ZaF7v2h.jpg
As you can see, the ejector has a spring tab that presses against the stock bedding block when the gun is assembled. This is intended to provide spring force that allow the ejector to keep in contact with the bolt body and eject the case when the bolt is pulled back fully. Here is a picture of the actual ejector:
http://i.imgur.com/pjZTkTW.jpg
As you can see, there is a spring tab that sits against the bedding block, and extends partially beneath the sear as shown here:
http://i.imgur.com/Q0QpRq1.jpg
The problem with this design is that the spring force is significantly greater than is necessary to reliably eject the case. This excess spring force pushes the bolt body against the action slots and causes binding and generally makes the bolt harder to cycle due to the excess friction generated when compared to a standard push feed bolt which is not under any spring loads. See here for the location where the ejector rides against the bolt at all times:
http://i.imgur.com/SsMyfrz.jpg
The interesting thing is that the ejector extends underneath the sear bracket, which is very close to the ejector spring tab. This gave me the idea to trim off the excess spring tab that normally would contact the stock bedding block, and simply use the sear bracket as the restraint to keep some spring tension and allow for proper operation while greatly reducing the lateral load on the bolt during normal cycling.
Here is the modification:
http://i.imgur.com/7a3UoGG.jpg
http://i.imgur.com/7MogA6s.jpg
As you can see, the spring tab has been trimmed back so that it does not protrude from underneath the sear. This does not affect operation of either the trigger or the ejector, both work exactly the same as before. I have just reduced the amount of leverage and spring force that the ejector places on the bolt body.
The action now is very smooth with all the work done to it including the PTG bolt, and it has very little binding. Ejection is equivalent to what it was before the modification. It does not take a lot of spring force to keep the ejector in place in the bolt head, all it is doing is contacting the case head as the bolt is pulled back exposing the end of the ejector.
I wrote this little post because while I was researching the CRF staggered feed Savage 110, there were a limited number of these produced and there is very minimal information on the web on this specific action type. I thought that it might help someone else out that was having the same issues and not finding much help due to the limited number of people who actually own and have worked on one of these.
http://i.imgur.com/sBKgAQU.jpg
The stock bolt body has fairly poor tolerances, so I thought that I would get a PTG bolt body to help tighten this up and minimize binding while working the bolt. So I installed one with larger diameter and lapped it to the receiver, which did improve the bolt operation significantly. However, I was still not happy with the bolt operation, and I began to suspect the ejector was the cause of this. When working the bolt with the action out of the stock, I realized what the problem was.
The CRF savage action has a standing ejector that mounts on the trigger group pin and sits in a machined slot in the receiver and also a matching slot in the bolt head. Here is what I am talking about:
http://i.imgur.com/fiUOjS0.jpg
http://i.imgur.com/qhRYWIt.jpg
http://i.imgur.com/ZaF7v2h.jpg
As you can see, the ejector has a spring tab that presses against the stock bedding block when the gun is assembled. This is intended to provide spring force that allow the ejector to keep in contact with the bolt body and eject the case when the bolt is pulled back fully. Here is a picture of the actual ejector:
http://i.imgur.com/pjZTkTW.jpg
As you can see, there is a spring tab that sits against the bedding block, and extends partially beneath the sear as shown here:
http://i.imgur.com/Q0QpRq1.jpg
The problem with this design is that the spring force is significantly greater than is necessary to reliably eject the case. This excess spring force pushes the bolt body against the action slots and causes binding and generally makes the bolt harder to cycle due to the excess friction generated when compared to a standard push feed bolt which is not under any spring loads. See here for the location where the ejector rides against the bolt at all times:
http://i.imgur.com/SsMyfrz.jpg
The interesting thing is that the ejector extends underneath the sear bracket, which is very close to the ejector spring tab. This gave me the idea to trim off the excess spring tab that normally would contact the stock bedding block, and simply use the sear bracket as the restraint to keep some spring tension and allow for proper operation while greatly reducing the lateral load on the bolt during normal cycling.
Here is the modification:
http://i.imgur.com/7a3UoGG.jpg
http://i.imgur.com/7MogA6s.jpg
As you can see, the spring tab has been trimmed back so that it does not protrude from underneath the sear. This does not affect operation of either the trigger or the ejector, both work exactly the same as before. I have just reduced the amount of leverage and spring force that the ejector places on the bolt body.
The action now is very smooth with all the work done to it including the PTG bolt, and it has very little binding. Ejection is equivalent to what it was before the modification. It does not take a lot of spring force to keep the ejector in place in the bolt head, all it is doing is contacting the case head as the bolt is pulled back exposing the end of the ejector.
I wrote this little post because while I was researching the CRF staggered feed Savage 110, there were a limited number of these produced and there is very minimal information on the web on this specific action type. I thought that it might help someone else out that was having the same issues and not finding much help due to the limited number of people who actually own and have worked on one of these.