muzzle rise

[lboos]

Need help,... what cause's muzzle rise when you fire a gun?.. my friend say's that if you hold a gun side ways [gangsta style] and fire it, the barrel will go horz. not vert .
i told him that it dosen't matter if you stand on your head, and fire the gun up side down that the muzzle rise will still be up [vert.].
how can i make this poor fellow understand why they call it muzzle rise? .

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[browningautorifle]

I spent a half hour trying to explain the Canadian gun laws to a fellow yesterday at a local gun show. Didn't work. Sometimes it can't be done.

[Badger]

how can i make this poor fellow understand why they call it muzzle rise? .

Try this ...

Muzzle_rise

Attachment 16762

Regards,
Doug

[Peter Laidler]

Muzzle rise.......... The very first Sten guns had a spoon billed 'depressor' fitted to the muzzle until those trialling it stated, after testing, that '......it served no purpose whatsoever and was a frill, if not a complete fraud'. The next 4 million didn't have them either because Newton, who discovered the theory of Newtons Laws went most of the way to agreeing with them in the practice.

Then, 50 years later we let my little boy, then aged 9 or so fire hundreds of magazines while the Sten gun was loosly tethered within a steel hoop while he was filmed on a high speed video. It didn't rise or go left or right. It just sat there and blasted away all morning and afternoon. And the more it roared, the more he liked it

Tell your friend to read up on Newtons laws of motion but DON'T believe all you're told either

[Patrick Chadwick]

i told him that it doesn't matter if you stand on your head, and fire the gun up side down that the muzzle rise will still be up [vert.].

Well it seems to me that the link posted by Badger (thanks for that!) shows quite simply that the rifle will always tend to rotate about the heel of the butt, because the recoil force, acting along the line of the barrel, is offset with regard to the center of MASS of the rifle, thus generating a turning moment. This is nothing to do with UP or DOWN, but is a simple leverage effect. So if the rifle is held upside down, this recoil leverage will act downwards, and if sideways, then sideways.

So (already cringing in anticipation of a lively response) the "unenlightened" friend is correct!

Before answering guys, please note that one of the 19th century muzzleloading experts - Gibbs or Metford, I think - went to the trouble of suspending (NOT clamping) a rifle on an axis that was true to the barrel and rotating it. He fired shots through all 360 degrees of rotation. Rifles that shot high left shot in the normal position shot low left if turned to the left, low right if turned upside down, high right if turned to the right etc. Check it out!

Patrick.

P.S: A detailed treatment can be found in "Geschosse", by Beat Kneubuehl, ISBN 3-7276-7119-X, Chap. 4.3.2. in particular, 4.3.2.4.

P.P.S: For those who may not have heard of him, Beat Kneubuehl is THE Swiss ballistics expert. No-one needs to trust what I say, but if you want to say he is wrong, you need a lot more than anecdotal evidence.

[lboos]

Before answering guys, please note that one of the 19th century muzzleloading experts - Gibbs or Metford, I think - went to the trouble of suspending (NOT clamping) a rifle on an axis that was true to the barrel and rotating it. He fired shots through all 360 degrees of rotation. Rifles that shot high left shot in the normal position shot low left if turned to the left, low right if turned upside down, high right if turned to the right etc. Check it out!

Patrick.

P.S: A detailed treatment can be found in "Geschosse",

P.P.S: For those who may not have heard of him, Beat Kneubuehl is THE Swiss ballistics expert. No-one needs to trust what I say, but if you want to say he is wrong, you need a lot more than anecdotal evidence.

I looked up some of these 19th century experts you mention, all i saw was that they wrote some book's in the 1800s, and Gibbs or Metford in around 1848 suspended a muzzle loader smooth bore and fired it at "ALL" 360 degrees.
My quest. was, what cause's muzzle rise when you fire a gun, not what happens when you have an explosion in a black powder smooth bore musket [suspended] in 1848 by a guy who wrote a book.
any way, i will take my 1911A1 out tomorrow and fire it in diff. position's and get back with you and give you my "expert" opin. in 2010. right or wrong.
Thank's for all the comment's .

[TDH]

A friend of mine made his own compensator for his AK. When he put it on and tried it he said it actually pushed the barrel of the rifle down. Alittle trial and error and a few more holes and now it stays practically steady. the way the excess gases escape is one componet in why muzzle jump.
Oh and by the way We have probably all heard the way the Thompson would rise rise on full auto. I tried it it doesn't work that way The Thompson M1 I shot just came back at me and not all that hard. The Thompson weighs just over 11 pounds.

[jmoore]

Especially w/ handguns, the weapon will torque away from the restraining points. There's two major ones to consider, although I can add more.

First, since your wrist is below the barrel axis in a normal firing position, the weapon will rotate upwards. Held "sideways" (gangsta-style as you call it) it will rotate in the horizontal plane.

Second factor to consider that will influence muzzle rise is that your feet are the restraint or pivot poit for your entire body. As the recoil force is almost invariably well off center of your feet, your entire body will tend to rock backwards, thus generating muzzle climb regardless of how the weapon is held.

Another factor that occurs when shooting one handed is that the weapon will tend to rotate to the left (assuming a RH shooter) as the mass of the hand itself acts as a restraint that is off axis to the bore centerline. Minor grip changes, however can negate a good deal of this influence.

As noted above, rifles have their own considerations, but the idea is the same. Torque, moments, inertia, it can get all "mathy" but the concept is pretty simple. Just look for constraints, and see how far off the centerline of the bore of the weapon they are.

[Patrick Chadwick]

ANswer 1)

First, since your wrist is below the barrel axis in a normal firing position, the weapon will rotate upwards. Held "sideways" (gangsta-style as you call it) it will rotate in the horizontal plane.

Thank you for that jmoore. The most extreme example of this that I have experienced is firing the Artillery Luger (Ari 08) one-handed. That almost pushes my arm up over the shoulder. (OK, I know I'm weak!)

The Luger mechanism relies on this off-axis kick for reloading. And it certainly works in a horizontal position. (Haven't tried upside down yet)


Answer 2)

what cause's muzzle rise when you fire a gun, not what happens when you have an explosion in a black powder smooth bore musket

This simple off-axis leverage has nothing to do with smoothbore or rifling, flintlock, percussion, rimfire or center fire. It is basic mechanics.
Try searching the LRML (Long Range Muzzle Loaders) forum to find out what Gibbs, Metford, Whitworth and others did. Not "a guy who wrote a book", but people who did their best with the means at their disposal to investigate what was happening. As jmoore has pointed out, what you will personally observe when you hold a gun in your hand is also going to be influenced by the way you hold it. Hence the suspension test. And the books by B. Kneubuehl really do explain and answer ballistics matters more than adequately for our purposes.

Patrick

[lboos]

I just got back from the firing range, and after firing 50 rounds with my snub nose 38, i find out that i was 100% wrong . i'll have to admit im hard headed.
I shot the gun in the normal position then side ways to the left and right, i also shot it upside down, about 10 shot's in ea. position and the muzzle rise alway's went to the position that i held the gun,...... so much for me being a ballistic expert. Thank you all for your comment's.