A rifle in two parts, connected by a shock absorber. One part comprises the barrel, sight, magazine, and firing mechanism. The other part is made up of the grip, trigger, and butt. Between the two is a shock absorber (spring-mass damper, rubber pad, etc.). The trigger uses a cable to carry a mechanical or electric signal across the shock absorber to the firing mechanism.
Rifles often have a shock absorber pad on the end of the butt. There is no similar protection for the grip and trigger portion that I am aware of. The design I propose would allow a soft shock absorber to be used, so the damper would compress by several inches during firing, greatly decreasing the shock of recoil. (Edit: use a damper that can compress by a foot or more.) With current designs, a shock absorber on the rifle butt must be stiff to prevent excessive gun motion.
For automatic weapons, an active control mechanism could vary the damping (possibly using magnetorheological fluid) for optimal damping.
There, I can forget about this idea, and think of happier things.
(Edit: The fishbones mean I didn't take this far enough. Imagine a small cannon, say 1 meter barrel length, with a magazine and firing mechanism similar to a modern rifle. To allow safe firing of this cannon, attach a 1 meter long coil-over spring+damper to the butt end. Attach a frame to the other end of the spring and, via bearings, to points along the coil spring and cannon. Add a shoulder pad and pistol grip to the frame for easy carrying of the ~50lb device, and add a flash suppressor that channels exhaust straight up to counteract the torque caused by placing the cannon above the shoulder pad. Now imagine that it is the weapon of choice for custard-hunting robot-cats from space. There.)-- sninctown, Jan 24 2009 NTW 20 - a gun freak's wet dream http://club.guns.ru/eng/ntw20.htmlComplete with hydraulic recoil damper [Custardguts, Jan 24 2009] Isis recoil reducer http://www.ableammo...&products_id=104141Off the shelf upgrade for small arms [Custardguts, Jan 24 2009] Enidine Hydraulic Recoil Buffer for AR15's (and the like) http://www.midwayus...t?saleitemid=380841This is getting repetitive... [Custardguts, Jan 24 2009] AR-15/M-16 Function Animation http://www.youtube....watch?v=WSqYvWib1ogsome things move past eachother, others maintain fixed relationship [Laughs Last, Jan 24 2009] Glock Function Animation http://www.youtube....watch?v=iPPgmvcsJNwsimilar, more clear [Laughs Last, Jan 24 2009] Double Recoil Action https://youtu.be/7lXllpsFX-4?t=363(Youtube) As Used on 280mm Nuke Gun [sninctown, Feb 15 2016] Seems that this would have the effect of reducing projectile muzzle velocity (maybe that's OK.) How much effect would depend on the relative masses of the bullet and the barrel. (cf. Newton's third law: delta p= F * delta t )-- csea, Jan 24 2009 Interesting solution for the "knee mortar" problem, but I don't see what you're trying to accomplish vis-a-vis normal rifles.-- FlyingToaster, Jan 24 2009 [csea] this would have minimal effect on muzzle velocity, because the air pressure pushing the bullet out of the barrel (F) would be the same, and the time the bullet spends in the gun (delta t) is about the same. Assuming a 2' barrel and speed-of-sound bullet, the bullet spends about 1.8milliseconds in the barrel. In 1.8 milliseconds, the barrel will travel backwards very little, so there will be minimal effect on muzzle velocity.
[FlyingToaster] this design absorbs the recoil and releases the energy much more gradually than a traditional rifle design. Imagine holding a rifle and having someone bang a sledgehammer on the end of it. You want the rifle to "give" like a spring or cushion to absorb the shock. A normal rifle cannot do this, except for a minimal butt cushion.-- sninctown, Jan 24 2009 When the barrel and firing mechanisms both reciprocate, how will the extractor and ejector work? And how will the next round be advanced while the magazine is coming along for the ride?-- Laughs Last, Jan 24 2009 yahbut the only place your body absorbs the recoil is the shoulder (with the exception of very low sight designs); you shouldn't be trying to absorb recoil with your hands.-- FlyingToaster, Jan 24 2009 [L.L.] the extractor, ejector, and magazine will all work as usual-- a normal gun moves backwards when it is fired, and everything still works. Yes, the mechanisms will move backward with a bit more acceleration in this design.
[F.T] True. In this design, the hands are insulated from the recoil so that the mechanisms+barrel can move a lot without you losing your grip. Otherwise the trigger guard would catch your finger and the gun jerk out of your hands.-- sninctown, Jan 24 2009 I've never had a trigger guard catch my finger... ah I see... cannon..... in that size, designs are recoilless (ie: rocket powered)... if you're referring to 20-30mm designs... you won't be able to lift them anyways, even .50cal (12mm) is almost impossible.-- FlyingToaster, Jan 24 2009 FT, I've toted an M2 .50 cal around for ... er, corrective training. But fire one without being mounted? No, Nay, Never!
However, since most modern machine guns have hydraulic recoil dampeners in the butt stocks, I would file this idea under "How about a less efficient way of doing that"-- MikeD, Jan 24 2009 I used to tote around a .30... that's heavy enough thanks. They do make .50 semi-auto rifles though; never fired one; quite a kick I hear.
[sninc] There's no reason *not* to have all the recoil at the buttplate on a rifle.-- FlyingToaster, Jan 24 2009 Dang. So it looks like this idea is 1) baked and 2) based on insufficient knowledge of rifle design. Thanks for the links [Custardguts] and [Laughs Last]! I have gained wisdom and looked stupid. Sweet.-- sninctown, Jan 24 2009 What I described is a "double recoil action", used on large artillery pieces to reduce recoil (see link).
I'd like to think what I propose is the first use of "double recoil action" in a rifle. Hard to say though.-- sninctown, Feb 15 2016 random, halfbakery