Advice on New Rifle Design

M

moobra

Inactive
I'm looking for advice on a new design that I have lodged a provisional patent on.

The action is quite unique. I have searched the patent literature extensively and haven't found anything similar. I won't provide great detail here- suffice to say it is something like a tilting bolt design without the bolt carrier.

Because the bolt does not require locking lugs it should be possible to produce a very cheap to manufacture bolt but I would like to make it even cheaper. I want to produce a gun that would be cost competitive with an SKS- hopefully in the $300 range (new), using AR-15 mags and specced for both military 5.56 and remington 223.

The aim is to produce a backup gun for the prepper movement who are currently unable to provide an AR-15 for their whole family/friends and tend to purchase WWII bolt actions or SKS and low grade AK-47 variants. I think a very low cost semi-auto compatible with AR-15 mags and ammo would be very sought after.

The idea is not to make a gun able to survive 50,000 rounds, but maybe 10,000- even if it takes a waiver to be signed by the purchaser. Most of these guns will just collect dust waiting for Armageddon and that's easier to accept at $300 a copy than $800-$1000 a copy.

My ideas to simplify the bolt and rifle cost are as follows:

In many bolt designs, a considerable amount of material is machined from the base of the bolt to allow it to pass over the mag lips. I think it would be easier to use a stamped steel "sled" shape piece that attaches to the bottom of the bolt. Probably two pins would be enough. The sled would also hold a channel for a full length ejector rod. The face of the bolt accepts the forces of firing as per normal. The sled just rides on the rails, the ejector fits between the mag lips, picks up the cartridge and feeds it into the bolt face recess as per normal.

By using a simple spring steel hook extractor at the top of the bolt and combined with the ejector rod sliding between the sled and the bottom of the bolt, the action would provide a simple vertical eject.

The only machining I see as totally necessary would be the recess on the bolt face for the cartridge- but there would be no need for a sophisticated extractor and spring.

The firing pin would be hammer fired because this can exploit the economies of scale of numerous hammer trigger groups on the market and keep the bolt simple.

I would like to know if this bolt would be better cast or milled in terms of cost. If cast, then the firing pin hole would need some kind of cast in recess to allow "gymnastic" fingers to insert a retaining spring on the firing pin and fit insert the assembled firing pin inside the bolt itself.

I'm also unsure if any cast bolt will need a minimal amount of machining anyway e.g. the firing pin hole may need to be drilled just to verify clearance. The pin holes for the sled attach to the bolt would need to be drilled as well as the hole for attaching the extractor spring. Pins may not be durable in these holes and hence they may need to be tapped for screws. Then there is machining the bolt face recess. If all this amount of machining is required anyway, would there really be any cost savings from just setting it up in a CNC mill and letting the whole thing be machined?

I'm aware that large production runs significantly reduce per unit costs and also that Ruger have great expertise in casting - after a significant investment in the technology.

Comments welcomed.
 
Investment casting will be cheaper for mass production, which is why Ruger does so much investment casting. But there is a big up front cost.

Milling will be cheaper for one offs and prototypes, essentially zero up front costs.

There will be a crossover point based on the number of units you are making where milling will become more expensive per unit and investment casting will be cheaper per unit. Without getting bid quotes I can't tell you what that number will be.

Jimro
 
I doubt my advice will be either welcome or accepted but here goes anyway.

First, how many guns have you designed? (I suspect this is number one.)

Second, how familiar are you with the patent process? (Same answer?)

Third, hire a patent attorney to research your patent and save you a lot of time and agony. If you don't have any money to do that, where would you get the money to set up a factory and start production?

Fourth, how much do you know about chamber pressures, residual pressure, bolt dwell time, spring capability, metallurgy, etc.

Fifth, if you do get a gun working, and you get a patent, where will you obtain the start-up capital (at least a half million) to buy/rent a shop, buy/rent machines, design and make/buy machine tools, make production drawings, sign contracts with parts suppliers, buy maybe 10k rounds of test ammo, build/establish a test range, etc., etc.?

I see, just off hand, several problems with what you want to do, but I don't have the full picture. As one example, how does a round get from the magazine/belt to the "sled"? How does the bolt lock? The major approaches (tipping up, tipping down, rotating, moving lock, etc.) were pretty well covered by, say, 1920.

The neat thing I see when reading about the arms pioneers like Colt, Ruger, Browning, is that the accounts usually go from "X had this great idea" to "X, our foremost firearms designer". There is just a little bit missing in between that the writer didn't think would interest us.

Jim
 
Thanks for everyone's comments. Very helpful and informative.

I probably need to explain the second part which is the marketing strategy. As they say, if you have a better mousetrap then the world will beat a path to your door.

Except "better" is in the eyes of the beholder. Better could be more dead mice per hour or the fact that all mouse gore is hidden and a flashing light just tells you to take the box to the trash.

Here's my "better" based on some questionable assumptions:

First, the prepper movement (no disrespect to anyone) suspect that in any large scale calamity then their guns will be siezed by govt- black rifles first.

My design is semi-auto, 5.56, uses AR-15 mags but is designed to be as unlike an AR-15 or any assault rifle as possible in appearance. Lots of cheap wood or wood-like synthetic, flat sided like a lever action. Closer to grand dad's deer gun than tacti-cool.

Second, although gas operated there would be a retrofit kit available that blocked the gas port, fitted a new pump foregrip and incorporated a pump mechanism. Not hard to do and really a remington 7615 is not much different from an AR-15.

Why do this? Because the prepper can hold up his civilian retrofitted pump action former semi-auto and say "officer, it's just a pump action". Any black rifle modified similarly would still look like a black rifle.

Would it even matter? Would authorities be that dumb? Or would they just sieze anything with a barrel? I don't know. Who does? But preppers may see some sense in caching a cheap as dirt semi auto that uses AR-15 mags, looks like a deer rifle and can be converted to pump if there is a general ban on semis.

Maybe credible, maybe not.

So really this issues are whether the design can be built cheaply enough.
Whether the cheapness can avoid liability issues.
Whether preppers would cache a $500 DIY AR-15 in preference.
Whether they think the deer rifle appearance is really an advantage
Whether they think the pump action conversion is really an advantage.

And whether all of this is any advantage at all compared to just caching a half dozen mosin nagants.....

Thanks again
 
Sorry but I can't figure out how to incorporate quotes in replies here.
Apologies if this violates site protocol.

> I doubt my advice will be either welcome or accepted but here goes anyway.

All comments are more than welcome!

> First, how many guns have you designed? (I suspect this is number one.)

Correct. But there are many things in my life that have been number one for me. Same as for most people I guess. Being born started it all...

>Second, how familiar are you with the patent process? (Same answer?)

I have several patents but none in firearms.

>Third, hire a patent attorney to research your patent and save you a lot of time and agony. If you don't have any money to do that, where would you get the money to set up a factory and start production?

The whole idea of the provisional patent process is that it's a cheap way to test out an idea without over committing to what may turn out to be a dumb idea. I have paid patent attorneys in the past once the provisional has generated interest.

>Fourth, how much do you know about chamber pressures, residual pressure, bolt dwell time, spring capability, metallurgy, etc.

One of the great things about trying to make a cheap version of an existing product is that there are lots of designs and design guides around. A huge amount of Engineering is from the manual. A bolt from material X with dimensions Y known to withstand pressures Z should do that anywhere in the universe. Even in a gun I design.

>Fifth, if you do get a gun working, and you get a patent,

You are confusing two things. Patents don't guarantee a working anything. There are plenty of useless patents. Patents protect an embodiment of an idea. Engineers turn patents into working products if the patent shows sufficient merit.


>where will you obtain the start-up capital (at least a half million) to buy/rent a shop, buy/rent machines, design and make/buy machine tools, make productione drawings, sign contracts with parts suppliers, buy maybe 10k rounds of test ammo, build/establish a test range, etc., etc.?

Why would I set myself up in manufacturing? I would like to be able to present an existing manufacturer with evidence of a cheap manufacturing process for a cheap design which they could make even cheaper.

With my non-firearm designs, that is what I have done- licensed the IP.

>I see, just off hand, several problems with what you want to do, but I don't have the full picture. As one example, how does a round get from the magazine/belt to the "sled"? How does the bolt lock? The major approaches (tipping up, tipping down, rotating, moving lock, etc.) were pretty well covered by, say, 1920.

Revealing the full picture would negate the point of patents. I understand your skepticism- quite understandable- but it's not something I can address. The original post was centred around general production issues that don't really need more detail than already provided I think.

>The neat thing I see when reading about the arms pioneers like Colt, Ruger, Browning, is that the accounts usually go from "X had this great idea" to "X, our foremost firearms designer". There is just a little bit missing in between that the writer didn't think would interest us.

Sorry I can't provide more detail. No offence intended. As you imply, I may have a really dumb idea but the provisional patent process is designed to cheaply test out new ideas and save us from the expense of dumb ones.

Providing more details in public forums is not a useful thing to do but I was hoping that members may be able to provide some insights on the general merits of machining bolts vs casting them. Clearly, the more details provided on the design I envisage, the more accurate and informed that advice could be, but I am more than grateful for whatever comments people are able to contribute based on my original posting.

Great forum!
 
I don't know that such a gun could be produced for $300. That's the cost of a S&W sigma new and cheaper than a hi point carbine.

How your gun locks is still a mystery, though I understand why. None of the delayed locking systems are particularly simple to create and require some extensive machining. So you'll have to have that figured out. Your bolt is probably going to require cnc machining and heat treating along with your barrel extension or assembly. I don't see any other way to make it safe to fire even a full magazine. Then you've got the barrel, which I assume will be made by another company. I'm assuming the receiver is either stamped sheet metal or molded plastic. Then you have to build your basic costs including excise tax into every model and get it into customer hands for $300 new. I don't see it happening and competing with $500 AR rifles.

My advice is looking into straight blowback 9mm carbines that are less bricky than the hi point, more reliable than the Tec 9, better trigger and ergonomics than the Mac 10, cheaper and more available than the Scorpion, Sub 2K and countless others, and take standard handgun magazines. I don't think you'll ever hit your price point in a .223 semi auto. It's hard enough to do in a rimfire
 
If you can bring it to market at that price and it is any good it will sell like hotcakes. At $500 not so much. You can get a decent AR rifle these days for under $500.
 
I was hoping that members may be able to provide some insights on the general merits of machining bolts vs casting them.
Click to expand...

As I pointed out, perhaps too briefly, in post 4 above, you are not likely to go straight from the foundry to the gun. A cast part is just a starting place and must be machined anywhere there is fit or movement.
These days it might well be simpler just to CNC machine the bolt from bar stock. It will CERTAINLY be simpler to machine developmental and prototype bolts.

The AK 47 was an example of that. Col. K designed the rifle to be made predominantly from stamped parts. But at the outset the USSR did not have the heavy duty precision presses to do the work. But they had a lot of machinists, so the early AKs and even the early semiauto fakos had milled receivers which the traditionalists thought superior.

Do you plan to prototype the rifle and deliver a working example to the manufacturer? I hope so, there was an example of that in the new Blue Press.
John Browning was well established with Winchester in 1890. They were selling three rifles and a shotgun they got from him. So he just sent them the drawings for a new rifle instead of taking the time to build a sample. Company engineers said it could not be made to work. Then he took the time to make up a prototype which of course worked just fine. This was the Model 1890 .22 pump, of which they made many thousands, along with its deriviatives the 1906, 62, and 62A.
 
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it's tough to give any meaningful advice on something that, for obvious reasons you cannot describe in detail.

I do, however, have a couple of comments about the premise of a cheap, "limited service life" rifle.

First off, its a thin line to walk to make a gun that will make a 10k service life (at max) and not crap out earlier. Possibly significantly earlier. A gun that will reliably make 10k rounds will almost certainly make 30k or possibly much higher. (and we're talking action service life here, not barrel accuracy life).

Yes, the idea of a (relatively) cheap, "break glass in case of Apocalypse" rifle has some appeal, for some people, it won't have much to people who already are shooters and gun enthusiasts. Nor, would I think it would be the choice of "preppers" for a couple of reasons.

IF it uses an AR magazine its at risk of becoming a banned gun. Semis are at the top of their list TODAY, but rest assured, they won't stop there. And, many places are banning the MAGAZINES themselves. So that's an Achilles heel for your gun surviving bans, right there.

Also, you mention "Simple" top ejection, which would preclude any receiver center mounted optics, something which might be important to potential buyers.

Good Luck!
 
Final word from here:

When it shows up on dealers' shelves with a $299.99 price tag, I will take a look at it and if I like what I see, you will get your $20 (your approximate percentage of retail). But I buy GUNS; I don't buy ideas or sketches of what someone thinks will sell to someone some way some time maybe.

Good luck.

Jim
 
Considering the current cost of an econo grade AR, I'll just have two rather than buy into a totally different platform.
The difference between $300 and $450 isn't a big factor for most users but the ability to cannibalize one to make the other run is priceless.
 
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