Installing a model 70 type safety on a 98 Mauser

I am have to add a scope to an old Jefferies .404J. Is there anything special a should know about installing a Dakota M-70 style safety in place of the original Mauser safety?

Hi Lon,
Yes, there are some things to know that may be helpful. The first thing is, what is required to make these work perfectly varies from one to another. Some require less work than others depending on the Mauser Bolt and the Dakota parts and how they work together. I have only done a few of these. One went together and worked without much fuss. The last one I did required a lot of machining and fitting to get right.
A lathe and a mill make these MUCH easier and in some case an absolute necessity.
The instructions supplied with the Dakota parts are not great and barely adequate for a first time doing one.
Here are a few pics and some explanation from my last one.

The bore in the back of the bolt needed to be opened up for the Dakota housing to fit in. I chucked it up in the lathe and skim bored the bolt.



In addition, the threads on the Dakota shroud were a little oversize to the threads in the bolt. I had to use lapping compound to fit the threads together and provide the necessary clearance for free rotation.

Additionally the scallop cut on the safety lever was machined about .015 out of location and had to be re-cut for a proper fit.



The cocking piece requires an angled surface to be machined or ground onto it



The firing pin requires a subtle little 45 degree chamfer ground or filed onto it to work properly with the safety lever. It’s difficult to communicate but becomes fairly evident where as you put things together and test fit.

One of the MOST critical things to know! When complete and fitted properly, the safety should draw the firing pin rearward .010-.015 when it is engaged. Meaning, with the bolt assembled and in the rifle, close the bolt with the safety off. When you engage the safety it should draw the firing pin and cocking piece rearward .015. If it does not, the fit of the sear, cocking piece and firing pin is not correct and when you disengage the safety the cocking piece/firing pin will not be caught by the sear and the rifle will fire.
You never want to modify the sear, but sometimes the surface on the cocking piece that engages the sear needs to be set back, just slightly!

I realize this explanation may be confusing and hard to follow. It’s hard to describe and even harder to provide much detail. How easy or difficult installing the Dakota parts ends up being is directly proportional to experience and aptitude. For anyone with some gunsmithing and machining experience, this isn’t too tough. For someone with no experience, I wouldn’t recommend it.
For a Zim PH, piece of cake!
If I can be of assistance I will be happy to help if I can.
There are a few folks around here with much more knowledge and experience than I that can probably give you good advice as well.
Keep us posted

Thank you so much for the great info. Unfortunately after reading the work description I am going to pass on this job! I MAY go to a "trigger 2 position safety".
You also gave me another piece of information a long time ago I had a Dakota traveller built. I was hunting elk with that rifle, I had a nice bull come pass I removed the rifle from safe and it went bang! I thought possibly I had my finger inside the trigger guard which I never do or did. A little later the same scenario took place with another AD! I contacted Dakota and sent the rifle back, I received the rifle back and in speaking with Management they said they found nothing wrong with the rifle (in confidence I spoke with one of their gunsmiths he told me a much different story)! Now I know what caused the AD. The rifle never repeated the AD after being returned, but I lost confidence in it and sold it after telling the new owner the whole story!

IdaRam said:

Hi Lon,
Yes, there are some things to know that may be helpful. The first thing is, what is required to make these work perfectly varies from one to another. Some require less work than others depending on the Mauser Bolt and the Dakota parts and how they work together. I have only done a few of these. One went together and worked without much fuss. The last one I did required a lot of machining and fitting to get right.
A lathe and a mill make these MUCH easier and in some case an absolute necessity.
The instructions supplied with the Dakota parts are not great and barely adequate for a first time doing one.
Here are a few pics and some explanation from my last one.

The bore in the back of the bolt needed to be opened up for the Dakota housing to fit in. I chucked it up in the lathe and skim bored the bolt.
View attachment 309058
View attachment 309067

In addition, the threads on the Dakota shroud were a little oversize to the threads in the bolt. I had to use lapping compound to fit the threads together and provide the necessary clearance for free rotation.

Additionally the scallop cut on the safety lever was machined about .015 out of location and had to be re-cut for a proper fit.
View attachment 309068
View attachment 309069

The cocking piece requires an angled surface to be machined or ground onto it
View attachment 309070
View attachment 309071

The firing pin requires a subtle little 45 degree chamfer ground or filed onto it to work properly with the safety lever. It’s difficult to communicate but becomes fairly evident where as you put things together and test fit.

One of the MOST critical things to know! When complete and fitted properly, the safety should draw the firing pin rearward .010-.015 when it is engaged. Meaning, with the bolt assembled and in the rifle, close the bolt with the safety off. When you engage the safety it should draw the firing pin and cocking piece rearward .015. If it does not, the fit of the sear, cocking piece and firing pin is not correct and when you disengage the safety the cocking piece/firing pin will not be caught by the sear and the rifle will fire.
You never want to modify the sear, but sometimes the surface on the cocking piece that engages the sear needs to be set back, just slightly!

I realize this explanation may be confusing and hard to follow. It’s hard to describe and even harder to provide much detail. How easy or difficult installing the Dakota parts ends up being is directly proportional to experience and aptitude. For anyone with some gunsmithing and machining experience, this isn’t too tough. For someone with no experience, I wouldn’t recommend it.
For a Zim PH, piece of cake!
If I can be of assistance I will be happy to help if I can.
There are a few folks around here with much more knowledge and experience than I that can probably give you good advice as well.
Keep us posted

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Thanks so much for the wonderful post with great info!