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designing a rifle and would like some input

Discussion in 'Rifle Country' started by justin22885, Apr 13, 2014.

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  1. justin22885

    justin22885 member

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    hey everyone, i am working on designing a rifle right now and i was looking to get some community input on it.. when i have finished designing it i will give the blueprints/plans to everyone here.. but the main purpose of it is this.. whether you love AR-15s, AKs, FALs, HK-91s or whatever it is you like, all of these rifles are designed for military, with the manufacturing support of entire countries.. im designing something that has more of the consumer in mind.. something for the people

    so, with the people in mind im looking to design something that isnt going to have to rely on major factory equipment like huges presses and large injection moulding or anything like that..

    the trigger housing will be folded and welded sheet metal not too dissimilar from the FAL lower.. but this trigger housing will contain an AR-15 trigger group and a trunnion designed to attach an AR-15 buffer tube and any AR style stock

    the upper will hopefully be a square or rectangular piece of tube steel, but if for some reason this isnt going to work out then will shoot for a very simple folded shape.. either way itll have rails spot or plug welded inside and a front trunnion that will be TIG welded or riveted in

    i will probably drill and tap a couple spots on the under-side of the front trunnion, and add a threaded screw-plate behind the magwell to allow different magwells to be used, they would screw in under torque in four locations and can be removed and replaced or changed.. first i will be working on FAL and AR-15 magwells for this

    for the barrel i havent decided for 100% what i will do.. i thought about using a barrel extension that contains the locking lugs and using a SCAR kind of system for attaching the barrel which uses screws through the sides of the receiver, and ive also thought about just using savage 10 series barrels which thread into the trunnion by hand over top of a headspacing gauge and is then fixed to the receiver via a barrel nut

    i was also thinking about extending the top half of the receiver out to the gas block for a single top rail that stretched from the gas block to the rear of the upper receiver.. and have a handguard attach to this

    also, im trying to determine what i will do for the bolt.. just messing around ive designed a 5-lug bolt, a 3-lugged triangular bolt, and one that utilizes two locking lugs similar to a mauser bolt.. but then later changed this idea to using the interchangeable bolt heads available for savage 10 bolts.. but i wanted to go with a simpler, possibly SCAR kind of carrier but this isnt possible with a 2 lug bolt as it requires roughly 80 degrees of rotation which cannot be machined into the carrier without removing a large portion of the carrier.. like the AK bolt

    so right now im trying to decide if i should go with a 5 or 6 lug design, or still use the savage two-lug bolt and instead of machining the cam groove into the bolt carrier, instead i machine it into the bolt body.. place the cam bolt in the bolt carrier instead

    ____

    so, id like to get some opinions on some of these ideas. get some feedback, hear some new ideas.. bottom line is that this isnt just going to be my rifle, but anyone who wants it since im focusing on simple to make parts, off-the-shelf parts (such as the AR trigger group and possibly savage barrels), and im going to give out the plans/blueprints freely so if anyone wants to make their own they will be free to do so...

    so.. what do you think?
     
  2. Tirod

    Tirod Member

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    In simple terms, a people's rifle should be able to be assembled by nearly anyone. The AK sure can't, and basing the design on the AR features would be a major improvement. That is because it's modular and meant to be assembled without any presses or special tooling.

    I would certainly use the AR barrel extension and bolt, precisely because it doesn't require pressing it into a receiver and simultaneously setting headspace. The barrel extension on the AR screws on, and with a micrometer like adjustment, the headspace is set and then the extension friction pinned in place. It's NOT gunsmith level work and that is the beauty of it on the assembly line.

    On the other hand, when Armalite designed the AR10 and M16, it was meant to showcase some advanced methods, and the forged aluminum receiver was the result. It's appropriate for mass production in an advanced technology environment, and does reduce weight and cost in high volumes, but the upfront costs are also high. In extremely low production or low cost manufacture, a folded sheet metal lower and even upper would be much more appropriate. The 1" ID upper could definitely be fabricated from tubing. The makers of monolithic uppers are even using extrusions, not forging, to reduce the costs even more.

    I speculate that someone could go into business successfully selling an upper and lower that aren't forged but do take all the AR parts. And a simplified version build to look like a traditional manual action with wood stock wouldn't be out of place. A left side straight pull "bolt action" would be the result.

    The M16 has influence a lot of battle rifle designs in the last 50 years, mostly because of the controls and barrel extension concept that are widely copied. They work, in the SCAR or BLR. Sounds like a good project to adopt them, because the extremely simple construction and lack of involved assembly are the key points to a people's rifle. With the combined cartridges available in barrel and bolts for the AR10 and AR15, there's over one hundred to fit nearly any taste. That alone should make it the preferred choice for parts.
     
  3. justin22885

    justin22885 member

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    well problem with the AR-15 bolt is it wont work with a SCAR/ACR/AR18 style receiver.. and id like to use a bolt thats a bit stronger too, as well as something larger since im designing this to be a .308 rifle with the capability of swapping out a barrel, bolt head (not necessarily the entire bolt) and the magwell to fire 5.56mm or other calibers in between

    so im looking at savage 10 bolt heads but also have drawn up a design for a 3-lug, and a 5-lug bolt.. the two-lug savage bolt due to needing 80 degrees of rotation to lock would need to have the cam groove on the bolt body itself and not the carrier

    interchangeable magwells will be bolted or screwed on so they are easily removed.. or riveted if you have no interest in changing the magwell,

    i have yet to decide a few things.. do i use the SCAR type of barrel which has the locking lug surfaces in the barrel, and the barrel is basically slid into the receiver and held with four T-25 screws?.. or do i use the savage 10 barrels which thread on by hand over a headspacing gauge and is then locked in place with a barrel nut?... do i go with the two, three, or five lug bolt?.. there are pro's and conts to each

    and lastly, since the upper half of the receiver will be extended out to the gas block (for a full length top rail), should the charging handle be on the fore-end, on the side of the receiver, left or right side, reciprocating or non reciprocating?

    so still many things left undecided at this point

    bottom line though.. AR-15s are easy to assemble, but costly and difficult to make from scratch, even machining out an 80% receiver is quite difficult.. my rifle will use a sheet metal or tube steel upper requiring only rails to be spot or plug welded in.. even the bolt will be significantly easier to fabricate than the AR bolt.. so not only will mine be easier to fabricate, but with only two.. MAYBE 3 springs in the entire upper receiver and fewer small parts itll be a lot easier to assemble than an AR too, if you could get the parts made by someone else
     
  4. Caliper_Mi

    Caliper_Mi Member

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    Not sure if you are intending to use the buffer tube as a receiver extension like in an AR or not, but my vote is not. Keep the bolt out of the stock so the gun can be fired with the stock folded.

    As far as the lockup system, something like the AR or AK has a big advantage over a traditional bolt gun that locks the bolt to the receiver. The AR's barrel extension and the AK's front trunnion both keep the forces and complex machining to a small part that can then be attached to a more easily made and less strong receiver. The advantage is in making sure the serialized part has as few difficult machining operations as possible. I've honestly wondered how long before we see a bolt action with a barrel extension design...

    Have you looked at the AR-180?
     
  5. justin22885

    justin22885 member

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    i intend on using some form of a front trunnion, have to for a sheet metal or tube steel upper.. whether the surfaces the lugs lock against will be in the trunnion itself or in a barrel extension held by the trunnion remains to be decided

    and the buffer tube attachment is purely for the installation of AR-15 stocks, nothing more, its going to use likely a two-spring recoil system that will be captive, so it wont just fly out when the receiver is taken apart.. i may design it to have a hinged side folding mechanism with a buffer tube adapter though so you can take off the shelf AR-15 stocks and use them as a side folding stock

    what im focusing on is whats the cheapest and easiest to machine, i want to rely on the fewest number of maintenance parts as possible.. so the least amount of springs and small parts as i can.. what will be important is that the end user can easily assemble it, and someone with a small machine shop can easily machine the parts

    also, i think it is important to have the entire travel of the bolt carrier in the upper.. buffer tube will only be for holding a stock and will have no springs.. i think its also important to have the magazine whether interchangeable or not, securely fixed to the upper.. it shouldnt have to rely on hinges, pins, or anything that can provide wiggle room, this should be a very firm connection.. the carrier needs to ride on rails.. lesser steel on steel contact surfaces will operate more smoothly.. and lastly, there needs to be some amount of mass to the carrier.. carrier-mass contributes more to an AKs reliability than any other feature

    ___

    so yeah.. if anyone has any ideas or would like to discuss this further we should pick individual features to discuss at a time to keep things organized
     
    Last edited: Apr 14, 2014
  6. Kanzenbach1

    Kanzenbach1 Member

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    Just make sure you don't accidentally recreate an ar-180. I think their lower was all stamped.
     
  7. Ian

    Ian Member

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  8. justin22885

    justin22885 member

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    well as of now nothings concrete.. still in its earliest stages.. havent even decides yet if i wanted a rotating bolt or a forward locking tilting block likely based off a CZ-58.. but im leaning towards rotating for a few reasons though tilting would likely be much simpler and easier to machine.. kind of 50/50

    actually, im not even sure just how important interchangeable calibers are.. AK doesnt have them, FAL doesnt, M14 doesnt.. but then again this is a rifle designed for the gun owner and not a military and the consensus seems to be that people love being able to buy one gun and do everything with it.. so thats why im focusing on making it a .308 caliber rifle, but with the change of a bolt head, barrel, and magwell it could just as easily be a 5.56mm rifle

    heres the three lug design im working on.. ive also been working on a couple different ideas for extractors.. since id like to have bolt heads that are interchangeable for inexpensive caliber changes, i thought it would be important to focus on an extractor contained within the bolt so each bolt head would have its own extractor specifically for that cartridge.. and i cut a slut for a frame-mounted ejector to aid in reliability by reducing the moving parts and springs needed for a bolt mounted ejector.. but im flexible with that decision

    2mo9ou9.png
     
  9. mr.trooper

    mr.trooper Member

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    You should make it so +80% of the weapon can be printed on a home model 3D printer, and all you would need to do is buy a factory barrel, magazine, and get something at the hardware store for a bolt and mainspring.

    The reciever, trigger group parts, and furniture could be plastic.

    Heck, if the LuLz Liberator can fire a 380 with plastic barrel, then any rimfire or shot shell cartridge would be an option.
     
  10. WestKentucky

    WestKentucky Member

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    I assume this is designed to be open source so anybody who wants to can pay a few bucks for plans and build away? If so I may play along.
     
  11. justin22885

    justin22885 member

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    well im just going to release the plans for free when its done.. probably via grabcad.com.. maybe register it under a license where i get a small royalty if someone wants to manufacture parts or rifles for other people.. or maybe just go on donations

    also, im avoiding the use of 3D printing any parts right now.. 3D printing is not a very strong and reliable means to make something thats going to take some abuse.. its literally melting one layer of plastic on top of another.. and anyone who knows anything about welding can tell you that melting one piece of material on top another will not hold much of a bond at all..

    however, certain parts could be injection-molded such as the trigger frame or the magwell.. since the magwell is separate it can be folded sheet metal, machined aluminum, or injection molded polymer.. it all gets attached to the rifle in the same way

    heres the bolt as i have it now.. ive simplified the extractor using the AK style extractor.. this only requires drilling a hole into the front of the bolt and the extractor is made from a a solid metal cylinder.. you can see where the spring goes, and where the pin is used to hold it in and give it something to pivot on.. benefit of this extractor is it can be part of the bolt head, allowing bolt heads to be interchangeable

    rkts88.png
     
    Last edited: Apr 15, 2014
  12. justin22885

    justin22885 member

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    well ian.. i just watched your video of the leader T2.. and yeah.. thats almost exactly the same bolt.. i had the idea of using a polygonal shaped bolt for ease of manufacturing and thought two wouldnt be neough, 5 lugs would be too much and settled on the triangle.. im actually glad to see this because it validates the design of the bolt

    ive also been thinking about going with two recoil springs and guide rods.. but ive been asking myself if these guide rods should lock into the rear of the trunnion and act as rails too or if im better of spot/plug welding rails into the upper.. if i do use the guide rods as the rails then there actually wouldnt need to be any welding done to the receiver.. the front trunnion could just be installed via rivets like an AK trunnion.. and if the lugs lock into recesses in a pre-headspaced barrel such as they do on the AR-15, containing all the pressure of the cartridge inside the barrel then the trunnion could possibly even be made of aluminum and save a lot of weight.. use a steel bushing where the gas piston rod contacts the trunnion so theres no aluminum on steel friction

    this has also got me thinking of the steyr AUG which uses two guide rods which i believe also act as rails.. but instead one of these guide rods also acts as the piston.. a non-reciprocating charging handle could act upon the other guide rod which in this case could be fixed to the carrier.. and if the springs were inside those guide rods.. all youd need is a couple rods to go inside of those to push against the spring.. then with absolutely no springs behind the carrier the upper receiver could be significantly shortened, saving weight and making a much more compact rifle

    now i can do all of this whether i use the triangle bolt or if i adopt and modify the CZ-58 tilting block system.. where the block doesnt tilt, but has sort of retractable locking lugs that are forced into the recesses when the carrier is forward.. i could maybe make this type of system compact enough to fix into the recesses of a barrel.. like how a remington 870 bolt works.. the gas system, recoil system, and interchangeable bolt faces would be present in either design

    so my question to you guys is this.. front locking tilting bolt design that uses retractable locking lugs like that of the remington 870 and CZ-58.. or the triangle rotating bolt similar to that of the leader T2?... or does anyone have any other ideas they may find worth consideration?
     
  13. barnbwt

    barnbwt Member

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    As I'm sure you know by now, there's advantages and disadvantages to the different bolt types. The bolt concept you showed, while simple to produce, has tapered lugs that have less surface area for a given diameter than a square of the same profile (like the Stoner bolt), so while probably simpler for a guy with a mill to carve up, it will need to be bigger/heavier than absolutely needed.

    The advantage of a rotating bolt over a tilting bolt (or locking piece) is twofold; first, the bolt can be incredibly short --theoretically the length of the lugs-- and second, the bolt face does not move relative to the cartridge, since both are co-axial. The obvious disadvantage of a rotating bolt is that the trunnions/extensions and bolt heads are very difficult to machine. Yes, you can use off the shelf AR parts for the hard stuff, but by that logic you will invariably end up building an AR clone; parts commonality for the sake of parts commonality leads to you designing new platform for the sake of a new platform. A truly better/different design will be fairly incompatible, and that is unavoidable.
    [​IMG]

    The advantage of a tilting locking piece, and more so, a tilting bolt, is that the bolt is extremely easy to machine, as is the receiver. However, unless you are attempting a tilting-bolt design that tilts at the front, its locking lugs will be further back, requiring more of the receiver to be built to carry immense bolt thrust. And if you tilt the front of the bolt, you will find it extremely difficult to design get enough lug engagement without a ton of bolt motion relative to the case head, which makes extraction and feeding much more complicated. One benefit to the tilt bolt that the rotating will never achieve, is the ability for an open breach; the VZ58 exposes nearly half the action (and the magwell nearly the entire other half) when the bolt carrier is retracted; something an AR can only dream of --just try fishing a jammed primer or other debris that makes its way into the barrel extension out by hand, but on the VZ an index finger can quickly and easily brush out the locking rails and you can visually glimpse right into the chamber. Tilt bolt actions with exposed bolt carriers like the VZ/SKS are also much more easily convertible to belt-feed (UK59 is a belt fed VZ58). The benefit of separate locking piece designs is they move the lugs forward, allowing more of the gun to be flimsy and lightweight, but at the cost of added complication and expense.
    [​IMG]
    InteriorofReceiver.jpg
    (staring straight down through the VZ58 locking lugs, magwell, and breach)

    Another action variety you may not have thought about is the Degtyarov, or locking flap. You have a central bolt body that is simply reciprocating into the chamber to feed rounds, with two locking flaps on either side that are pushed outward into recesses by the bolt carrier. The open-bolt designs (not legal in the US) are stupid-simple, but even a striker/hammer fired closed bolt is very simple to visualize, and there is no easier receiver to make by hand; it's basically a tube with two notches cut in the sides. These are also by far the easiest to convert to belt feed (hence why the DP28/DPM had a belt conversion, and all subsequent variants like the RPD and DShK were belt fed). The "Skorparev" compact carbine design I am working on is a miniature DP28 in 7.62x25, and has a receiver built from telescoped steel tubes brazed together and extremely simple bolt pieces (nearly two-dimensional machine parts). I differed from the true rear-locking Degtyarov designs by putting the locking lugs up front (first attachment), which makes the beefy part of the receiver shorter, but also makes the flaps more complex; the DP28 flaps are 1/8" thick rectangular plates with a rounded end --hard to get simpler than that.
    2006-01-01_225645_boltcomp.jpg
    RPD, DP28, and DShK bolts, all in a row (the Degtyarov Trifecta :cool:)
    [​IMG]
    And, my Skorparev concept. The idea here was as small/light a legal-length straight stock rifle as possible, cheap and easy to make, that is gas operated, uses PPSH drums/mags, and is automatically ambidextrous (has auto-switching ejection based on user hand position)

    Another design I am almost positive you have not considered, is the falling block. If you think about it, a falling block is basically a front-tilting bolt with a really long swing radius. Not very many semi-autos have exploited this concept, but the Madsen LMG was/is a very dependable if awkward looking design. I am pursuing this design for my MP57 project in 5.7x28, since the tilting bolt requires very little momentum to operate, making it in my mind perfect for super small magnum cartridges. Falling blocks are the linear analogue to the rotating bolt, and they posses all the same benefits such as extremely efficient load transfer and extremely compact size. One huge benefit over all reciprocating bolt designs is there is no reciprocation along the barrel axis, so the overall length of the action is equal to the cartridge. The lone detraction is a big one; they require the entire bolt face to scrape over the chambered case head, and a separate mechanism to extract/feed the new round. This is very foreign to folks who are all used to reciprocating bolts doing this work, but the job of feeding/extracting falls to the bolt carrier in the case of a repeating falling block. But check out the second attachment to see just how easy the 'barrel extension' is to make. For my rifle, the extension is milled into the barrel blank itself before chambering, and is the only structural part in the whole gun --the rest is low stress stuff, just like in an AR. But see how much more compact it is (the dark grey square on the end of the 16" barrel is the entire receiver, and contains everything; a small tappet piston out front of the chamber powers everything)
    [​IMG]
    MAD19501cut.jpg
    And here's the Madsen LMG. You think a Broomhandle Mauser has weird internals, this thing is like nothing ever seen before or after, and ran like a top up against contemporaries like the Browning BAR :what:. Still in use in Rio, I hear. Ian (forgottenweapons.com) has an excellent video and discussion of the operation and internals, as well as a comically-badass run and gun session
    Incomprehensible operation and machine work, brilliantly simple magazines --too bad they are in a terrible place, which is why I opted to figure out a why to use PS90 mags for the MP57 design.

    TCB
     

    Attached Files:

  14. barnbwt

    barnbwt Member

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    Sorry for the humungulungus post replete with mesmerizing animations. Gun design is just one of those things I get really excited about when I see people with know-how getting involved. Disclaimer: If you don't have a real good understanding already, be sure to bone up on the assorted NFA/GCA/local gun building laws, as well as an understanding of ATF regulations/recommendations regarding your particular design. Seek out the info before building it and posting the proof on Youtube :D (Disclaimer over)

    TCB
     
  15. WestKentucky

    WestKentucky Member

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    It's totally backwards thinking to the rest of this thread but I would love to see another browning recoiling barrel. Make that happen in a pistol cal carbine and it would be an old school new school combo that would be neat. With modern steel it should be able to be downsized to take the smaller rounds easily. The length of travel would be dependent upon springs and recoil so it should be easy to build long to take everything from .380 to 10mm build it longer and heavier and you have rifle caliber capability. Make your reciever 4 ft long and you can handle 338 lapua and 50bmg...maybehttp://firearmshistory.blogspot.com/2010/09/actions-recoil-action-long-recoil.html?m=1
     
    Last edited: Apr 16, 2014
  16. justin22885

    justin22885 member

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    i really like the locking flap idea.. seems very similar to another idea i was working on.. it seems very similar to a tilting bolt, but improved

    as to the falling block.. no, i didnt even consider that.. its a very interesting LMG.. unfortunately the footprint on it is huge but its nice to see interesting and different designs like that.. todays guns all look and function alike and i honestly find it to be quit boring so im always attracted to the more exotic

    as for tilting block, the idea i had in mind was more along the lines of the CZ-58 but front locking.. but im going to look more into the DP-28 mechanism as its so close to something else i thought of that i think it warrants a bit more investigation
     
  17. WestKentucky

    WestKentucky Member

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    Out of curiosity, are you looking long term at bull pup or standard configuration?
     
  18. WestKentucky

    WestKentucky Member

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    And are you side, top, bottom, forward ejecting?
     
  19. barnbwt

    barnbwt Member

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    That Madsen is recoil operated, and shot 8mm, so the concept of a recoil-op rifle is very sound (the MG42 was, too). The problem with pistol cal rifles is the barrel is so heavy that the recoil won't budge it. Not to mention a tilt-barrel like you almost always see is a total no go. So, you're stuck with straight-recoiling designs which require the receiver to ride the whole length of the barrel (heavy, $$$). One possible option is the Pedersen hesitation lock, which manages an essentially recoil-operated action along with a fixed barrel (it's a hybrid of blowback and recoil-op) but I wouldn't want to be the small businessman trying to market this following Remington's act on the R51 (or the Model 51, either, since that was a tough act to follow :) )

    TCB
     
  20. rcmodel

    rcmodel Member in memoriam

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    justin22885
    Do you have any knowledge or schooling in firearms grade steel selection and heat treatment?

    That's going to be a dangerous hurdle for you to jump if you don't!

    rc
     
  21. barnbwt

    barnbwt Member

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    "as to the falling block.. no, i didnt even consider that.. its a very interesting LMG.. unfortunately the footprint on it is huge"

    You may want to take a closer look. The Madsen is huge because it's recoil operated, and the barrel/breechlock have to slide around inside a sturdy housing. Compared to a BREN (a comparable LMG with similar mag placement) the action is very stubby. The actual breechlock is no longer than an 8mm cartridge, and you would be operating it via piston or gas pressure that adds no additional length as opposed to letting it slide around. It is actually the shortest you can make a firearm action without a moving barrel (blow forward is shortest).

    Here's a snubbie in use by Rio police:
    Madsen_LMG.jpg

    "Do you have any knowledge or schooling in firearms grade steel selection and heat treatment?"
    Use 4130-type carbon steels and you can hardly go wrong. Just design with a healthy safety factor, avoid super-hardened steels, and test carefully and incrementally, and it's pretty much impossible to blow yourself up. As I recall, the BREN receiver was straight mild steel, and it was a rear-locking arrangement, too :eek:. Just add enough metal and you're covered. The Skorparev is designed to withstand 90,000psi ultimate loads, 60,000psi proof loads, and 40,000psi operating loads, which is more than enough margin to cover my butt :D

    TCB
     
    Last edited: Apr 16, 2014
  22. justin22885

    justin22885 member

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    i wouldnt mind the ability to make the rifle adaptable in terms of its configuration.. i mean, with interchangeable bolt heads, a left ejecting bolt can be installed.. with some ambidextrous mechanism for the charging handle you could easily convert it to a left handed rifle.. so why not allow it to be easily expandable for a bullpup, or even a full-stock rifle (like the SKS).. and ejection will be either side.. itll be switchable

    so the way i had it envisioned now is i was planning to extend the top half of the upper receiver out to the gas block.. the lower handguard would contain the bottom and side rails and would just hook onto the gas block, then somehow lock to the receiver in the rear.. to take down the rifle i wanted to re-use the mainspring to add tension to the latching mechanism.. like on an AK.. so if someone made a bullpup stock you could remove the lower receiver and the lower handguard, hook a one piece stock in the front on the gas block and latch it in the rear just like the original lower receiver.. maybe make trigger packs that can easily be installed

    ive also been thinking of using a striker fired trigger group so that the striker itself could have an extension on it brought to the front of the action so the trigger, disconnector can both be moved forward and the linkage that would normally be between a front trigger and a rear trigger will instead be on the striker itself with no need for a rear trigger or disconnector.. and there should be plenty of clearance near the bottom of the upper receiver for that linkage

    ___

    im going to look more into the DP28 and similar mechanisms.. that idea is really starting to grow on me as a very compact, very strong, simple to machine system but since i want the ability to change calibers which likely means having whichever bolt.. any bolt lock to the barrel so i will have to make the DP-28 setup front-locking
     
  23. justin22885

    justin22885 member

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    also, you can actually select the alloys and hardness of your metals and run a stress simulation at various amounts of pressure and see the results it has on the parts.. face it.. we have it easy.. the gun designers that started these ideas deserve tons of respect for having to do it without modern luxuries of 3D CAD, simulation software, and CNC machining
     
  24. barnbwt

    barnbwt Member

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    I wouldn't put too much faith in FEM, even if it does generate pretty pictures; at the end of the day, the model is still based upon your assumptions so you must remain skeptical (it is pretty cool, though :D)

    "wouldnt mind the ability to make the rifle adaptable in terms of its configuration"

    One modularity idea I had that seemed worth someone else's time was to split the mag well; think of an AR upper/lower, only the front half of the magwell is integral to the upper. This would allow an upper change to alter the length of the magwell, resulting in a far greater variety of cartridges that could be quickly swapped in. Taken further, the Degtyarov bolts are obviously very scalable, so quickly designing them for a multitude of cartridge lengths and case heads would be a snap. You'd be limited only by how fat a single-stack magazine you could fit in the magwell (or you could use the magwell itself as an internal magazine for the biggest stuff, with feed rails integral to the upper)

    TCB
     
  25. justin22885

    justin22885 member

    Joined:
    Nov 9, 2009
    Messages:
    2,102
    go to the future weapons website or look them up on youtube.. look for the G41 rifle.. that is EXACTLY the mechanism i had envisioned, started drawing up this idea only to find out the germans beat me to it by about 70 years... the idea i had envisioned for a front locking system with retractable lugs was to put the lugs on the inside like that and use the firing pin to push them apart.. i had no idea how id get the carrier to pull the firing pin back.. was thinking of having a knob on the rear section of the firing pin or striker that the carrier would push against to unlock the bolt but this system works too

    also, looking at the G41 bolt ive also been thinking you could make the body of the bolt out of a steel pipe, or thick walled steel tubing.. maybe even thread the front of the bolt body and have interchangeable bolt heads that just thread into the front of the bolt body.. or just push one into the front and drive a pin through to pin the bolt head into the tubular body

    its very similar to the DP-28 and RPD but is front locking and the entire system is narrow enough that this could easily be designed to lock into a barrel extension

    downside of this system as he points out in the video is that if the two lugs arent perfectly matched.. then all the force would be on one lug which would easily break and cause a major failure so you have to ensure both lugs are precise.. but it seems the DP28/RPD locking system would have those same requirements.. but it doesnt seem like anything that can be solved with some precision CNC machining equipment.. or really careful milling.. what do y'all think?
     
    Last edited: Apr 16, 2014
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