If any of the following options were offered to the general public, would anyone actually want them? Im just rather curious as to what new developments in gun mechanisms are actually wanted these days.
1. a bolt action rifle that by rotating the bolt handle around the bolt body allows for left or right handed operation with spent casings being ejected to the correct side for the selected hand of operation. IE right handed shooter has the ejected cases ejecting to the right of the rifle, and vice versa.
It would need an unconventional lockup surface, but otherwise I don't see any reason that this wouldn't work. I'm sure any of the resident gunsmiths could chime in as to the metallurgical or manufacturing difficulties of a design like this.
If the concept was well executed, I could see people buying it.
2. A semi automatic rifle that also has the built in funciton of a standard bolt action rifle. Merely move a few buttons around to get from semi auto to bolt action using the same cartridge for each method of operation.
Already exists. Any gas-op semi automatic rifle intended to fire rifle grenades will have a gas cut-off valve. Turn one dial and bingo! Straight pull bolt action. FALs and XCRs both have this feature, and if you're so inclined AR-15s can be retrofitted with adjustable gas blocks and tubes, although I make no statement as to the function or reliability of those after market parts.
If you don't like that annoying return spring shoving the bolt back forward for you, simply add a mechanism that disconnects the return spring from the charging handle, as on the mondragon rifles. I'm fairly sure that no currently manufactured rifle has such a feature.
3. semi automatic rifle action that can be semi auto or a bolt action, but uses different ammunition for each mode of operation. Example, semi auto .410 shotgun, but a bolt action .45 colt rifle.
Frankly, I would be a little curious as to why it couldn't use both ammunition types for both methods of operation.
for 3, here is my reasoning.
a short action rifle most likely will not leave you enough room for a blowback mechanism such as used on the 10-22 if you do no want a part of the semi auto action hitting your face everytiem you shoot.
With the exception of hasty lash-ups of auto pistols, like a Mauser C96 in a rifle stock, and oddballs like the ljungman, rifles do not have reciprocating parts that can come anywhere near your face because they are enclosed in a receiver. I'm also fairly sure that the ljungman slide does not reciprocate during fire.
I'm also fairly sure that a straight blowback action, "such as used on the 10-22" will not be suited well for .45 and 410.
to avoid that i have a feeling you would need to stay within the action lenght during semi auto firing. that can be solved in one of two ways.
-you carry around a semi auto mechanism, think pedersen device for 1903 springfield rifle, that you must manually insert. not fun when you need 3 or 5i minutes to get semi auto combat funciton when attacked by wild dogs, etc.
-the second idea is that you have a two part bolt. imagine charge handle of ar 15 is your regular bolt action part you use for that brass saving single shot shooting. Then you suddenly feel like spraying lead and brass real fast, you flip a switch and suddenly the spring loaded ar 15 bolt head is popping like it should.
bad imagery but still it gets the idea across, or imagine a 10-22 with a forward assist. FOR single shot firing simply push a switch and the forward assist becomes the regular masaur style bolt action, and flip the switch and you suddenly have a regular semi auto 10-22 with a forward assist.
im working on a different theory at the moment, think pedersen device with a built in chamber converter for smaller cartridge using same diameter bullet. say instead of bolt action .308 win, you have semi auto 7.62x39 in same reciever and barrel.
7.62x39 usually fires a .311 in diameter bullet, and I think the case diameter exceeds somewhat the .308's, but I get what you're saying.
Again, I'm not entirely clear as to why the gun can't run semi auto and straight pull bolt action for both rounds. It would be a challenge to do so, to be sure, but it seems preferable to, say, fiddle with a gas valve and recoil spring setting to change caliber and mode of fire between .45 and .410.
