Can you broach an actions lugs on a lathe?

[Papa Charlie]

I will admit I am not a machinist, I have enough knowledge and experience to do turning, boring, turn internal and external threads and other basics on my lathe.
One of the projects I want to try is to make my own action, can you broach am action on a lathe and if so how?
I have been looking around YouTube to find how or if you could and if so how, but haven't found anything that I can see would work for this. I have found methods for cutting key ways and of course the rotating broaches, but how would you ensure that the lugs are symmetrical with each other? Do you just turn the broaching tool over in the tool holder? Seems like that would be too simple, maybe it is.
Is there an easy way to broach the lugs and the bolt guides?

 

[carlsbad]

Broaching has been pretty much replaced by EDM. I have a supply or EDM cut action blanks if I ever find the time to build them.

A good broach will cost you a couple of hunderd dollars and then you'll need a good press and you'll have to make your own fixtures, slotted bushings, and shims. It will be extremely time consuming. You'll have to do one side at a time so you'll need some luck or a good setup to get them perfectly 180 degrees apart.

I haven't done a lot of broaching so I can't speak to all the challenges you'll face but if you have the time, I think it can be done.

Here is a guy that did it:

https://www.practicalmachinist.com/...er-raceways-lugways-ya-someone-had-do-349085/

PS you'll need a lathe and mill to make the components but he broaching will be done on the press.

 

[Papa Charlie]

Thanks for the response. I am familiar with EDM, we use them for removing 3D printed parts from the build plate at work. I am estimator in Additive Manufacturing, seen them doing it but never operated.
Am I reading your post correctly in that you have or are able to get round blanks with the broaching already done? That would surely make life a lot easier.

 

[Robert]

Tf your intention is to make the receiver and bolt, you can envisage a full diameter bolt body, with lugs same diameter as the bolt body and make the bolt stop as bolt guide. This would left only some .5 inch of counter-lugs to cut in the receiver, a much easier option.
R.G.C
c-g-designs.blog4ever.com

 

[Papa Charlie]

Tf your intention is to make the receiver and bolt, you can envisage a full diameter bolt body, with lugs same diameter as the bolt body and make the bolt stop as bolt guide. This would left only some .5 inch of counter-lugs to cut in the receiver, a much easier option.
R.G.C
c-g-designs.blog4ever.com

I see what you are saying. I would only have to broach the lugs themselves and not the the entire length of the receiver. I assume from the picture on the website you provided that the bolt would be guided by the bolt handle slot in the receiver?
Seems like this would allow for a much stronger, stable action bolt relationship instead of having only the lugs and the handle area of the bolt doing the supporting.

That is assuming I am envisioning this correctly.

Edit: Thinking about this further, I could leave the lug ends rounded from the turning and likewise the receiver path between the receiver lugs could be milled and left with a U shape instead of a rectangular shape as produced by a broach.

 

[Ggmac]

I see what you are saying. I would only have to broach the lugs themselves and not the the entire length of the receiver. I assume from the picture on the website you provided that the bolt would be guided by the bolt handle slot in the receiver?
Seems like this would allow for a much stronger, stable action bolt relationship instead of having only the lugs and the handle area of the bolt doing the supporting.

That is assuming I am envisioning this correctly.

Edit: Thinking about this further, I could leave the lug ends rounded from the turning and likewise the receiver path between the receiver lugs could be milled and left with a U shape instead of a rectangular shape as produced by a broach.

Maybe not what your goal is but , if you want your own action without broaching you could find an old action make a full size ( large body bolt ) make your receiver and use the donor for the lugs . Cut what you need from it , turn , thread and use in your receiver . You could even use aluminum as the receiver body , a few points needs steel bolts inserted , such as the primary extraction cam .
Hope this makes sense , too much Mucinex cold med .

 

[Robert]

I see what you are saying. I would only have to broach the lugs themselves and not the the entire length of the receiver. I assume from the picture on the website you provided that the bolt would be guided by the bolt handle slot in the receiver?
Seems like this would allow for a much stronger, stable action bolt relationship instead of having only the lugs and the handle area of the bolt doing the supporting.

That is assuming I am envisioning this correctly.

Edit: Thinking about this further, I could leave the lug ends rounded from the turning and likewise the receiver path between the receiver lugs could be milled and left with a U shape instead of a rectangular shape as produced by a broach.

The link is only my signature. Even the bolt of the pictured rifle has its bolt stop lever sliding in a slot milled in the full diameter bolt to ensure guidance.
R.G.C

 

[Dusty Stevens]

Find some pictures of a hall action. Thats the original simple hand broached action with the full dia bolt body. He broached them with a hand ground lathe tool and advanced the scrape .001 at a pass- just like cutting a cut rifled barrel.

 

[hpshooter]

"He broached them with a hand ground lathe tool and advanced the scrape .001 at a pass- just like cutting a cut rifled barrel."

My dad would cut internal splines on the lathe in a similar fashion. Ground a tool that resembled a boring bar incorporating the proper spline profile that would cut as it was drug OUT of the bore, lock the spindle, advance the tool into the bore, dial in .001 or so depth of cut and hand crank the carriage towards the tail stock. Had a degree wheel and reference indicator on the outboard end of the spindle so he could rotate to the next position and repeat the process. Many passes and lots of time involved but it worked. Utilize what you have to work with when time is more plentiful than money.

I believe a lug raceway could be cut by dragging it in. I have cut a 4" long .250"x.125" key way in an aluminum pulley this way, slow but it worked. The thread on the practical machinist site that was in a previous post here is very interesting. EDM is the way to go if you have access to it but it isn't the only way.

 

[paperpuncher]

They can be single point cut, it would be cumbersome to do on a lathe. A shaper will do the job pretty straightforward. If you want wire edm cut blank try here
Gary Breiling
210 S McClellan ST
McLeansboro, IL 62859
618-383-3170

glbreil@frontier.com

 

[DaveTooley]

If I'm not mistaken Allen Hall used a shaper. I think on both the bolt and receiver.

 

[butchlambert]

I highly recommend Gary Breiling.