Building a Custom Rifle on the Pre-64 Winchester Model 70 Action

We are always pleased to play a role in helping a client design and build a custom rifle, and regularly produce pre-64 Winchester model 70 actions as the foundation for a customer's rifle build. As way to help address the questions we are most frequently asked, this Campfire post covers the basics of building a custom rifle on the pre-64 action.

1957 standard action with a Douglas bull barrel in .243 Win and set in a factory Monte Carlo stock

For nearly 80 years, the pre-64 Winchester model 70 action, with its bulletproof controlled round feed mechanism, quality of manufacture, and elegant simplicity, has been the standard against which all other bolt actions are judged. As a result, there is no mystery why the pre-64 action is widely regarded as the ultimate starting point for a custom rifle build.

1955 standard action with a Lilja match grade barrel in .30-06 and set in a McMillan stock

Once you have settled on a chambering for your new rifle, you are ready to select the appropriate receiver. We cover this topic in detail HERE, but some quick rules of thumb are:

• Non-magnums - Select a "Standard" receiver
• Magnum rounds with an unfired length up to 3.34" - Select a "Short Magnum" receiver
• Magnum rounds with an unfired length greater than 3.34" - Select an "H&H Magnum" receiver 

With the correct receiver selected, you'll need an appropriate bolt housing, plus a laundry list of other parts to finish your action. The full list of parts for a complete action are:

• Receiver **
• Bolt housing **
• Firing pin
• Firing pin spring
• Firing pin spring retainer
• Bolt sleeve with safety
• Ejector with pin and spring **
• Bolt stop with spring and plunger
• Trigger group
• Magazine box **
• Magazine follower **
• Magazine spring **
• Extractor ring **
• Extractor **
• Trigger guard
• Floor plate

** these items are specific to the chambering of the rifle, so it is important to select the correct part for the chambering of your build.

Individually purchasing every part needed to complete a pre-64 action is not cost-efficient, which is why we recommend builders pursue one of two lower-cost alternatives:

1. Steal the action from a "donor" rifle - This path involves finding a rifle from which you can salvage the action. A low-end pre-64 model 70 can be purchased for $650-$750, making this the lowest cost path - at least initially. The donor rifle option has some downsides in that you may get some parts with condition issues. A donor rifle action also may not have the exact parts needed for your build, unless you are chambering in the same cartridge as the donor rifle. Regardless, it is an option worth considering if you are looking to save some money on your project.
2. Take advantage of the pre64win.com "BUILDER" program - This is a turn-key solution to getting a complete action, with all parts inspected, matched and assembled, at a 15% discount off of our individual part pricing. Our complete actions are truly complete, with everything you need to build a rifle, other than a barrel and a stock. You can read more about the pre64win.com BUILDER program HERE.

A complete standard action from pre64win.com

Now that you have your action, here are three things to consider before purchasing and installing a barrel:

1. Blueprint your action - Often referred to as "accurizing", blueprinting an action ensures your entire rifle action, chamber and barrel bore are precision-aligned to the axial centerline of your bolt. Accomplished in a  machine shop with the receiver in a lathe, blueprinting includes truing the receiver face, truing the receiver barrel threads and truing the bolt face. Blueprinting in our shop also includes lapping the bolt lugs to the receiver lugs to ensure even and proper bolt engagement within the receiver. This is a level of precision which is not possible in a mass-produced factory rifle. As good as the pre-64 model action is, blueprinting is one way it can be improved on, ensuring maximum precision of the completed rifle action for lasting accuracy.
2. Choose a quality barrel - Nothing will do more for making your rifle great than selecting a quality barrel. There are many great manufacturers out there, including Bartlein, Douglas, Hart, Lilja, Krieger, Shilen, etc. and the price difference between an average barrel from a second-rate manufacturer and a superb barrel from a premium manufacturer will be the best money you spend on your custom rifle project. 
3. Have a chat with your barrel manufacturer -  In addition to barrel contour and material, there are some details of your barrel design which are pretty technical and can make a big difference in how your finished rifle will shoot. Specifically, you will want to choose the barrel length, rifling design, and twist rate which is appropriate for the loads and bullet weights you intend to use in your rifle. All of the top barrel manufacturers are extremely helpful in working through these details with you.

1963 short magnum action with a Christensen Arms carbon fiber barrel in .300 Win Mag and set in a Brown Precision stock

We're making good progress toward completing your rifle, but we still need to get your new barrel mounted to your action and complete your rifle with a stock. Selecting a stock will largely be a matter of personal preference, but your barrel installation will again require precision machine work, both for a proper mating to your action, and also for proper finishing of your chamber and the final headspacing to your bolt. Selecting a good shop with a qualified machinist will ensure the barrel installation and completion of your chamber are properly accomplished.

The final step will be to furnish your completed barreled action with a stock. The material and style of your stock will largely be a matter of personal preference and this choice alone will not meaningfully affect the finished accuracy of your rifle. However, almost every rifle will benefit from some "accurizing" of the stock. No mater how precisely your stock is inletted, it is nearly impossible for machine-cut (let alone hand-cut) inletting to form a perfect contact surface for your action and barrel to mate with. This is where you should consider some form of bedding for your stock. While bedding should never be done to an original and collectible model 70, it makes little sense to carefully accurize an action and fit it with a precision barrel, only to screw it into a non-bedded stock with uneven contact points and the associated stress and distortion this will put into the action. In most cases, we recommend a fully floated barrel with a fully bedded action, using Devcon Plastic Steel epoxy, or some other very stable (and non-glassed) bedding material.

1949 target action with a Hart barrel in .338-06 and set in a custom Claro walnut stock

 We hope this article is helpful and useful for you as you consider a custom rifle build. If you are considering a custom build, or have questions about it, please don't hesitate to send us a note - we're very happy to help.

Happy shooting!

Justin