# Why don't guns fire through their center of mass? **URL:** \ **Category:** Factual Questions\ **Created:** [March 30, 2009, 9:13pm UTC](https://boards.straightdope.com/t/why-dont-guns-fire-through-their-center-of-mass/491353 "2009-03-30T21:13:58Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![iamthewalrus\_3](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)\ **Post date:** [March 30, 2009, 9:13pm UTC](https://boards.straightdope.com/t/why-dont-guns-fire-through-their-center-of-mass/491353/1 "2009-03-30T21:13:58Z")
Reading this thread about [robot-controlled weapons](http://boards.straightdope.com/sdmb/showthread.php?t=512138), and another recently about how a gun kicks when you fire it, I wondered: why aren’t guns engineered so that they only kick back, rather than back and up. As far as I know, a great deal of the difficultly in rapid firing is keeping the gun pointed where you want it, since the recoil tends to send the barrel up. But it doesn’t have to be that way. It only is because the grip is not in line with the barrel that the firing creates torque. Clearly, there would be some engineering challenges in making guns that way. Handguns in particular are made with the barrel on top of the grip to aid in sighting and because it makes the whole package more compact. But, surely there’s some value in a redesigned gun that would distribute the recoil straight back, rather than back and up. And long guns should be even easier to redesign. They’re already braced against the shoulder to fire. So all you need to do is make the stock come directly out the back of the barrel, rather than back and down from it. What am I missing? ---
**Author:** ![thirdname](https://avatars.discourse-cdn.com/v4/letter/t/d07c76/32.png) [@thirdname](https://boards.straightdope.com/u/thirdname)\ **Post date:** [March 30, 2009, 9:21pm UTC](https://boards.straightdope.com/t/why-dont-guns-fire-through-their-center-of-mass/491353/2 "2009-03-30T21:21:54Z")
Modern military rifles almost all have a straight-line design. Look at an M-16. The barrel, action and shoulder stock are in a straight line with the shooter’s shoulder. It’s not exactly centered because it goes to the top part of the shoulder rather than the exact center, but it’s close. In a handgun, putting the entire action in front of the hand would make the gun a lot longer. ---
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [March 30, 2009, 9:26pm UTC](https://boards.straightdope.com/t/why-dont-guns-fire-through-their-center-of-mass/491353/3 "2009-03-30T21:26:09Z")
One thing that Gene Stoner was trying to do with the AR-15 was to send the recoil straight back (into the recoil buffer). This design marked a departure for WWII and early post-WWII era rifles such as the M-14, FN-FAL, etc. The M14E2 (the squad automatic weapon version of the M14) featured a modified stock to accomplish this task as well. German GPMGs of WWII also tended to transfer the recoil straight back. The M1919 and the M2 would as well. Rob ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [March 30, 2009, 9:31pm UTC](https://boards.straightdope.com/t/why-dont-guns-fire-through-their-center-of-mass/491353/4 "2009-03-30T21:31:33Z")
It would be a much simpler task with a revolver than with any sort of automatic. Basically redesigning so that the barrel and hammer are firing from the bottom of the cylinder rather than the top. A bit odd looking to say the least, but managable. Automatic designs which have largish pieces of metal slamming back and forth present a bit more challenge. Most of them currently have a path of travel bringing the slide back over the hand which would have to be somehow moved to where it still has clearance. Just shifting it down won’t work for both not having clearance to actuate and by putting the case extraction right into the palm of your hand. Flipping the extractor to the left side presents the same issue for lefty shooters. Straight up just seems like a bad idea. Hot brass in the eye really isn’t fun. There is a design for large caliber weapons which has part of the recoil redirected into a block of metal going down which neutralizes most of the tendency to climb. But it’s still an experimental piece. Not saying it can’t be done. Would just take some work. ---
**Author:** ![wolfman](https://avatars.discourse-cdn.com/v4/letter/w/a8b319/32.png) [@wolfman](https://boards.straightdope.com/u/wolfman)\ **Post date:** [March 30, 2009, 9:34pm UTC](https://boards.straightdope.com/t/why-dont-guns-fire-through-their-center-of-mass/491353/5 "2009-03-30T21:34:17Z")
> [@iamthewalrus\_3](#): > > What am I missing? The Impact into your wrist from a large handgun. Anything like a .44 Mag or Casull has a lot of impact going into your hand quickly. The wrist doesn’t compress in a straightline motion very well and would make you very sore(if not tendinitis or dislocation) very quickly, but it is effective at rocking back in a shock-absorbing method fairly effectively. ---
**Author:** ![iamthewalrus\_3](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)\ **Post date:** [March 31, 2009, 4:56pm UTC](https://boards.straightdope.com/t/why-dont-guns-fire-through-their-center-of-mass/491353/6 "2009-03-31T16:56:30Z")
> [@wolfman](#): > > The Impact into your wrist from a large handgun. > > Anything like a .44 Mag or Casull has a lot of impact going into your hand quickly. The wrist doesn’t compress in a straightline motion very well and would make you very sore(if not tendinitis or dislocation) very quickly, but it is effective at rocking back in a shock-absorbing method fairly effectively. As long as you don’t lock your elbows, wouldn’t they absorb the shock effectively? ---
**Author:** ![Gbro](https://avatars.discourse-cdn.com/v4/letter/g/c6cbf5/32.png) [@Gbro](https://boards.straightdope.com/u/Gbro)\ **Post date:** [March 31, 2009, 6:05pm UTC](https://boards.straightdope.com/t/why-dont-guns-fire-through-their-center-of-mass/491353/7 "2009-03-31T18:05:21Z")
The [Weaver stance](http://weaverstance.com/) is my favorite to control the recoil to almost straight back. Pressure out and counter-pressure back accomplish this. [Mag-na-porting](http://www.magnaport.com/) is designed to reduce barrel jump also. ---
**Author:** ![Fish](https://avatars.discourse-cdn.com/v4/letter/f/bc8723/32.png) [@Fish](https://boards.straightdope.com/u/Fish)\ **Post date:** [March 31, 2009, 6:08pm UTC](https://boards.straightdope.com/t/why-dont-guns-fire-through-their-center-of-mass/491353/8 "2009-03-31T18:08:21Z")
Center-of-mass gun design isn’t very cool. If you can’t turn the gun gangsta-style, what’s the point? 🙂