Any gun designers here?

[twoblink]

I'm trying to design my own gun (what am I thinking??!?!?) and would like to bounce some ideas off of anybody who is also trying to design their own gun..

I have a few radical ideas, and have great spacial thinking, but lousy drawing skills.

So if you are interested in helping me design a few guns, please let me know.

Thanks.
Albert

 

[James K]

Well, I won't do drawings, but you can try your radical ideas and maybe I can say if I think they will work.

Jim

 

[twoblink]

I'm trying to design a rifle;

Specs:

under 40 parts
striker fire
no parts under 3/4th of an inch big
basic layout, like an M1A
based on .223
Can use AR15/M16 magazines
Secondary Recoil absorbtion system like HK USP's.
A better gas system then the M1A
a double kidney lobed trigger system, based on cable pulleys to the trigger itself, which means it's DAO, and cannot go full auto (which I'm not a fan of, and so it's by design)
I do however, like a single main spring for both recoil absorption and lug lock. That's a good design.

Field strips into 5 major parts (like most pistols) barrel is interchangable rather easily. Breaks down into stock, barrel, trigger housing, gas tubes, and main spring.

Albert

 

[James K]

Well, some of those goals are pretty well met by the AR-180, though I have not counted parts. It uses a medium stroke piston, a copy of the Walther G.43 system. The M1 carbine also sounds well in line with your ideas. Also, examine the M1 rifle (Garand) if you can for how a design genius makes parts perform more than one function. The old Mauser 98 is also the product of genius; one example is the undercut extractor.

As to your ideas, I am not sure what advantage a trigger cable and DAO would have over a conventional trigger. I will note that unless considerable thought is given to safety interlocks, a straight drive striker is at least as likely, if not more so, to go full auto than a hammer-firing pin system. And safety interlocks (like those of the Glock) are usually small and use small springs (violating your part limit, plus your "nothing under 3/4 inch").

I am not sure what you mean by "a single main spring for both recoil absorption and lug lock". In firearms terminology, the main spring is the spring that fires the gun (the hammer or striker spring). If you mean the recoil spring/return spring, I don't know of any gun that does not use the same spring(s) for both purposes, although I know of a couple that don't have any recoil springs, depending bolt mass to contain pressure sufficiently (.22 LR) and requiring manual bolt closure.

I also know of no gun that depends on a spring for locking the lugs. The spring may propel the bolt forward, but the locking is done by a cam of some kind that is very positive, and made in such a way that the gun cannot fire until the bolt is positively locked (or at least forward in a blowback design). Depending on a spring for a critical safety function may cause problems if the spring weakens or breaks.

Jim

 

[twoblink]

I'm basing the design off the M1A/M1Garand. Basically trying to design what a Mini-14 should have been.

Going full auto is probably not possible in the design I have in mind, because the trigger is what resets the striker, not the recoil, so you'd have to keep pulling the trigger to fire. Not really possible for stray/spray fire.

What I was talking about was something like the Garand's spring system as far as recoil, not so much the lockup.

 

[James K]

Well, those rifles you mention all have hammer systems, not striker firing. There have not been many striker fired semi-auto rifles, though there are a lot of pistols, notably the Glock.

A problem in designing something like a DAO rifle is that the main spring on a rifle has to be much stronger than on a pistol because the rifle primer has to be harder to retain the higher pressure. The human finger being what it is (and the Designer not readily available for advice), that means a very hard and/or long trigger pull for DAO.

Using the trigger to retract and release the striker is fine (like I say, there is the Glock) but you also need a means of holding the striker back some when the bolt goes forward, or else you will likely get erratic full auto fire. Again, study of the Glock or one of its clones is recommended. Also study striker fired weapons like the Browning 1910/1922 and the Colt/Browning .25 calibers.

The M1 rifle (only the kiddies call it a "Garand") gas system is a full stroke piston type. The M14 uses a gas cutoff and expansion system that is less sensitive to ammunition variations, since it uses only what gas it needs for operation. The Mini 14 uses a direct piston; the AR-180 uses a medium stroke piston like the G.43. The FAL uses a medium stroke piston, but the piston is one piece, and has to be removed from the front. The M1 carbine uses a short stroke piston; the M41 Johnson uses short recoil, not gas.

Jim