# Accuracy vs. rate of fire in automatic weapons? **URL:** \ **Category:** Factual Questions\ **Created:** [July 3, 2003, 6:09pm UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083 "2003-07-03T18:09:48Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![Turbo\_Dog](https://avatars.discourse-cdn.com/v4/letter/t/ce73a5/32.png) [@Turbo\_Dog](https://boards.straightdope.com/u/Turbo_Dog)\ **Post date:** [July 4, 2003, 2:41am UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/21 "2003-07-04T02:41:10Z")
The M61 uses a “Gaintwist” rifling, in that unlike most barrels, it is not the same degree of spin throughout the barrel, it increases on barrel length. This helps the stabilization for the rate of 6,000 smp rate. Also important in “gatling” weapons and to a smaller extent, all automatic weapons, is what is called the “exit angle” which is the final degree of spin that is placed on a projectile on muzzle exit. Modern aircraft software corrects for this, along with all other factors for the optimum “Shoot” cue. ---
**Author:** ![Cardinal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cardinal/32/4000_2.png) [@Cardinal](https://boards.straightdope.com/u/Cardinal)\ **Post date:** [July 4, 2003, 10:00pm UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/22 "2003-07-04T22:00:16Z")
I thought I understood this, but it seems that you’re saying that the gatling type guns compensate by putting a lot of rotation on the projectile. I’m asking if the software corrects for the fact that the spinning barrel is throwing the bullet down (or up?) somewhat. ---
**Author:** ![Cardinal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cardinal/32/4000_2.png) [@Cardinal](https://boards.straightdope.com/u/Cardinal)\ **Post date:** [July 4, 2003, 10:06pm UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/23 "2003-07-04T22:06:26Z")
I thought I understood this, but it seems that you’re saying that the gatling type guns compensate by putting a lot of rotation on the projectile. I’m asking if the software corrects for the fact that the spinning barrel is throwing the bullet down (or up?) somewhat. ---
**Author:** ![Turbo\_Dog](https://avatars.discourse-cdn.com/v4/letter/t/ce73a5/32.png) [@Turbo\_Dog](https://boards.straightdope.com/u/Turbo_Dog)\ **Post date:** [July 4, 2003, 11:45pm UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/24 "2003-07-04T23:45:25Z")
Gatling systems spin a bit more than usual to help stabilize a projectile more because of the rotation of the barrels. As a rule, the guns shoot a bit left and down, once they reach optimum rate compared to line of fire (boresight). The aircraft software takes this, along with many other factors, into account and makes corrections. That’s how an F/A-18 with a nose mounted gun, and an F-14 with a wing root mounted gun, with both guns being of the same configuration, can actually hit a target. ---
**Author:** ![radar\_ralf](https://avatars.discourse-cdn.com/v4/letter/r/b2d939/32.png) [@radar\_ralf](https://boards.straightdope.com/u/radar_ralf)\ **Post date:** [July 5, 2003, 12:18am UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/25 "2003-07-05T00:18:51Z")
Aha! Maybe I detected a clue in your last post, **Turbo Dog**. Is the twist (with gain) of the rifling in the barrels opposite to the rotation direction of the barrels? Also, is the distance that the ground crews use to “sight in” the gun on the aircraft still 1000 inches? IIRC, that’s the distance that was once used. ---
**Author:** ![Turbo\_Dog](https://avatars.discourse-cdn.com/v4/letter/t/ce73a5/32.png) [@Turbo\_Dog](https://boards.straightdope.com/u/Turbo_Dog)\ **Post date:** [July 5, 2003, 12:26am UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/26 "2003-07-05T00:26:39Z")
**radar ralf** yes, the rifling of the barrels is clockwise while the gun rotation is CCW and 1000 inches is still a standard in a few of the basic specs. Me thinks you may have a bit of experience with the big guns? 🙂 What’s your story dude? ---
**Author:** ![radar\_ralf](https://avatars.discourse-cdn.com/v4/letter/r/b2d939/32.png) [@radar\_ralf](https://boards.straightdope.com/u/radar_ralf)\ **Post date:** [July 5, 2003, 12:40am UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/27 "2003-07-05T00:40:58Z")
Long ago and far away, I once had to rely on the occasional use of such systems. I therefore learned a bit of stuff so I could talk intelligently with the folks who were experts on the subject. Does “Spooky” ring a bell? ---
**Author:** ![Turbo\_Dog](https://avatars.discourse-cdn.com/v4/letter/t/ce73a5/32.png) [@Turbo\_Dog](https://boards.straightdope.com/u/Turbo_Dog)\ **Post date:** [July 5, 2003, 1:02am UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/28 "2003-07-05T01:02:26Z")
Ah, an old supporter of such tracer towers:) Although I wasn’t in the age bracket to be on either end of the goodness of Spooky, I know of the contributions. The current version of Spooky with the 25mm system has a bit of tension between the USAF and the USN/USMC (me), but it still is an awesome platform. Not sure of your affiliation, but OORAH and Semper Fi to you. My salute is rendered:) ---
**Author:** ![radar\_ralf](https://avatars.discourse-cdn.com/v4/letter/r/b2d939/32.png) [@radar\_ralf](https://boards.straightdope.com/u/radar_ralf)\ **Post date:** [July 5, 2003, 1:15am UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/29 "2003-07-05T01:15:01Z")
Right back at ya, Turbo Dog. Happy 4th. Too bad some of the other folks here haven’t had the pleasure of seeing the “fireworks” that the old AC-47 or the new AC-130 is capable of. ---
**Author:** ![Turbo\_Dog](https://avatars.discourse-cdn.com/v4/letter/t/ce73a5/32.png) [@Turbo\_Dog](https://boards.straightdope.com/u/Turbo_Dog)\ **Post date:** [July 5, 2003, 1:30am UTC](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083/30 "2003-07-05T01:30:55Z")
Happy indy to you too my friend and I couldn’t agree more. A pillar of fire is a gorgeuous sight. For someone who has seen it from a vantage that I believe you have, it is a beauty that I can only imagine. [Previous page](https://boards.straightdope.com/t/accuracy-vs-rate-of-fire-in-automatic-weapons/186083.md?page=1)