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brainstorming a custom bolt action build

Foxman333

Plastic
Joined
Jun 25, 2014
Location
United States
Hello all, this is what a got going on. I'm jumping into this head first. My plan is to scale up a savage action for a .338 lapua. The final action will have an OD of 1.5" and a length of just over 10". It will be modeled after a center feed action. I'm still in the process of fine tuning the scale and all the measurements. The whole project is still on paper for the most part (I've started gathering materials only). As far as the machining aspect, I am very confident that I can overcome all the challenges I'm going to face. Before I start on the .338, I am going to do a practice run to standard savage long action specs on just a piece of scrap round bar. I have already, and will have many more questions that I'd like to run past all of you to get your 2 cents. Also, just as a forewarning, I'm probably going to bump this thread down the road as I run into more obstacles.

The first topic that comes to mind is one that I've been pondering for quite some time.

As far as closing a stock, I know I want to go with a Choate tactical. Also, I am going to make it a detachable mag setup. Now here is the thought that I have been tossing around. Since the final .338 action is going to be a custom size already, I'll more than likely have to make some modifications to the stock. That being said, the remington screw spacing offers the best options for me (left hand, long action, and detach mag bottom metals). Theoretically, could I machine a beefed up savage long action, but give it remington action screw spacing so it could use remington stocks? I'm not afraid to try things if it can be done, and I can fix anything but a broken heart.

-pat-
 
I think you will find when scaling up ANY action not many "standard" parts will fit... However, if you are designing from scratch "BASED ON" another action anything you want to do has more than one possible path. My .50BMG is based on a Remington 700 action but designed from the ground up to meet my goals and requirements. I designed around a standard model 700 trigger. However, because the action was lengthened and MUCH bigger in diameter, a standard stock was not practical. I suspect you will arrive at the same conclusion at some point.

As for the helpfulness of responses here (or anywhere for that mater), your results will vary.
 
That is a good point. I thought about the possibility of making a chasis for it, but was hopeful that I could just buy one and open it up to fit. I guess I'll have to throw that on the drawing board again.
 
You don't have a clue.

Aww, iddn't the twoll cuute?...


Anyway, Fox, if you haven't already, you need to get a copy of "US Rifles & Machine Guns" by Colvin & Viall. Original and reprint editions are available, or you can download the PDF from Google Books. It contains the complete drawings for the US Model 1903 Springfield rifle, with pictures and descriptions of fixtures and setups, and even details of heat treat.

You might also want Frank de Haas' "Bolt Action Rifles" doesn't contain dimensions, but it has useful pictures of many rifle actions, good for examples of different ways things have been done. There are various editions going back to the early '70s; you can snag one off half.com or Amazon; they're all pretty much the same.

Otteson's "The Bolt Action Rifle Vol.1" covers military actions, Vol.2 covers commercial actions. They're detailed engineering studies and quite useful. Even used copies are expensive, but you can get PDF versions on CD.

You mentioned "Savage", which uses the traditional left/right bolt raceways cut into the side of the receiver. Cutting those raceways is the deal-breaker for many potential builders. There's a guy on Gunbroker selling receiver blanks with the center hole and raceways EDM'd into a bar of 4140. Otherwise you'll have to broach or "rifle" the raceways, which will involve building some tools.

A variant is the "vertical raceway", like the Lebel, Berthier, or Mosin-Nagant. With these, the raceway is done with an end mill from the top, through the rear bridge, up to the receiver ring. The short section at the front can be pecked out with a form cutter on the lathe or mill.

The third option is the "fat bolt", where there isn't a raceway; the receiver is bored round all the way up to the locking lugs. The bolt is usually guided by a slot cut in the bolt and a screw or pin in the side of the receiver.

What tooling you have or are willing to invest in will determine which locking lug setup you go with; the rest of your decision tree will descend from that.


Since I don't have to prove my manliness by insulting strangers on the internet, I'll be happy to answer any questions I can.
 
I had planned on getting a copy of Ottesons "the bolt auction" volume 2 with the next bit of good overtime I get at work, and will add the other two you mentioned to the list as well!

As far as the raceways go, I would like to do as much as it myself as possible. Although, as a backup, I can have them WEDMed should I feel I can't machine them to the tolerances I would like.

The first method I am going to try is with a lathe. I have access to two large lathes at work which are plenty beefy enough. I plan on making single tooth broach style cutter that I'd move back and forth with the carraige hand wheel. I know this method is time consuming, but I got pretty good results on a smaller scale. I might even invest in some broaches and a press too, it all depends on how well things go when I get there.

I do like the idea and simplicity of a fat bolt, and I think sometime down the road, I will do a .50 with that design.

I appreciate the input!
 
Don Nielson is a very gifted tool maker. He has been in the rifle business for many years, a long range World Record holder and rifle builder.
When you get a little older with a little experience you will understand.
 
The Springfield was made with a single tooth broach to cut the raceways. The Colvin book gives the depth of cut and strokes per minute. They used a sort of mutant cross between a rifling machine and a power hacksaw.

You could do it on a lathe with the cutter held between centers and the receiver bolted to the slide, but it would take longer, of course.

By the way, if you're going to mount anything to the slide... it might be worth your time to build a Myford-style worktable you can bolt to the slide. The Myford used tee slots, but drilled and tapped holes and normal milling clamps will work just fine. A worktable and an angle plate will greatly simplify a lot of strange workpiece setups on the lathe, and you can move it from machine to machine or take it home.

Mm, did you find Raymond Benwood's description of broaching a receiver using modified commercial broaches? A copy is at A Guide to Drilling, Reaming, and Broaching a Bolt-Action Receiver at Home Benwood modified the broaches to give them the proper shape for a Mauser bolt, but whether that's necessary for your design is up to you.

- Dave (Club Clueless #2!)
 
he says it's "on paper"... in this day and age, shouldn't it be on computer? and in some type of solid modelling software? at the very least a free and open source one?
 
Your going to have to send me a picture of the myford table you are talking about! Chances are ill make one or something similar.

As far as drilling the hole, here is what I got in mind:
I plan on facing both sides and turning the blank with a light cut to true it up. Then center drilling both sides, and then drilling with a undersized bit 1/2 way from each end. Then also using an undersized bit and drilling all the way through and ream to size... I have used a similar method at work for deep holes with some pretty tight tolerances and they passed our QC check. I might use D bits when I do the reciever to gain as much accuracy as possible. Also might ream under size a thousandth or two and hone to size.

Once I have the hole and the raceways cut, I'm going to make a mandrel and turn the outside concentric to the bolt.

Like I said, I could easily pay someone to wire edm it, but I am hell bent on doing it 100% myself
 
Your going to have to send me a picture of the myford table you are talking about! Chances are ill make one or something similar.

As far as drilling the hole, here is what I got in mind:
I plan on facing both sides and turning the blank with a light cut to true it up. Then center drilling both sides, and then drilling with a undersized bit 1/2 way from each end. Then also using an undersized bit and drilling all the way through and ream to size... I have used a similar method at work for deep holes with some pretty tight tolerances and they passed our QC check. I might use D bits when I do the reciever to gain as much accuracy as possible. Also might ream under size a thousandth or two and hone to size.

Once I have the hole and the raceways cut, I'm going to make a mandrel and turn the outside concentric to the bolt.

Like I said, I could easily pay someone to wire edm it, but I am hell bent on doing it 100% myself


OK!!!
What is the purpose of this build, to show yourself that you can do it? Why not base it on a 700? Are you going to make the trigger also as I don't know of a good one for a Savage. Are tou going to make the bolt also?
 
OK!!!
What is the purpose of this build, to show yourself that you can do it? Why not base it on a 700? Are you going to make the trigger also as I don't know of a good one for a Savage. Are tou going to make the bolt also?


Basically, yeah. It's an idea that popped in my head and it turned into something that I have to accomplish, and I am way way to stubborn to ever give up on it. I'm not basing it off of a 700 for logistical reasons- I do not own one lol. My father was always partial to savages and as it turns out, the Apple never falls far from the tree. All but one of the bolt actions I own are savage. I stripped one down and started from there.

I was planning on NOT making the trigger and fitting it with a factory one, although I'm sure I'm gonna have to get crafty to do that.

I am going to make the bolt, yes. I'm going to have to. The reciever is going to be about .5" longer than the standard long action, larger diameter lugs, larger bolt diameter, left hand bolt, and right hand eject.
 
Myford: Myford Tri-leva lathe "It's not a lathe, it's a cult!" Step back up to lathes.co.uk for hours of cool lathe stuff. I'm not talking about making a whole carriage like the Myford, just an adapter to replace or add to your compound.

Drilling from each and and reaming has been done successfully. I'm seldom so lucky, though.

Once you can mount the receiver to the table, you can drill any old hole, put a cutter in a piece of round stock long enough to go through the workpiece, held between centers, and let the carriage move the workpiece along the flycutter. It's a good way to make a really straight hole, which you can then ream or hone to size.


Trigger assembly: the Remington 700's bits all come in a handy little box held to the receiver by two pins, and they're commodity items. There are also zillions of old ones people took off when they put fancy aftermarket triggers on. Unless you have some nifty idea you want to try, it would be hard to justify NOT using one...


Bolt: back in the day, most factories used form cutters with horizontal mills, plus some faceting, and then hand polishing, to form the round bolt body around the lugs and handle. Separate bolt heads weren't unknown, but mostly went away by the time the 20th century rolled around. Nicholas Brewer's Savage 110 design used a separate bolt head and a multi-piece bolt. It's a bit complex, but it's designed for easy manufacturability using screw machines. You can make facet cuts to form the lugs on the bolt head.
 
Myford: Myford Tri-leva lathe "It's not a lathe, it's a cult!" Step back up to lathes.co.uk for hours of cool lathe stuff. I'm not talking about making a whole carriage like the Myford, just an adapter to replace or add to your compound.

Drilling from each and and reaming has been done successfully. I'm seldom so lucky, though.

Once you can mount the receiver to the table, you can drill any old hole, put a cutter in a piece of round stock long enough to go through the workpiece, held between centers, and let the carriage move the workpiece along the flycutter. It's a good way to make a really straight hole, which you can then ream or hone to size.


Trigger assembly: the Remington 700's bits all come in a handy little box held to the receiver by two pins, and they're commodity items. There are also zillions of old ones people took off when they put fancy aftermarket triggers on. Unless you have some nifty idea you want to try, it would be hard to justify NOT using one...


Bolt: back in the day, most factories used form cutters with horizontal mills, plus some faceting, and then hand polishing, to form the round bolt body around the lugs and handle. Separate bolt heads weren't unknown, but mostly went away by the time the 20th century rolled around. Nicholas Brewer's Savage 110 design used a separate bolt head and a multi-piece bolt. It's a bit complex, but it's designed for easy manufacturability using screw machines. You can make facet cuts to form the lugs on the bolt head.

I will most certainly make a table like that. Very handy lookin.

I could achieve similar results with a large horizontal mill right?

To shape the bolt head, I was planning on turning the lug portion on a lathe then milling it into shape with a horizontal rotary table set up.
 
As you get older you will see that being bull headed ain't always the best way. Some of the guys that have been on the forum for a while see some of this and most just disappear. Their projects barely got off the ground.
Now getting that out of the way I would kinda do what you are saying on the bolt lugs. If you have patience you can search this forum and you should be able to find photos of this being done. You should also find the home made tool to cut the very slight helix on the lug abuttments in the receiver. You can make a receiver not needing the EDM or broached raceways. I would recommend that you do a little research first before diving into this project.
 








 
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