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Posted: 11/20/2008 2:26:00 PM EDT
lets say you placed the butt of your rifle against a block wall, then you shoot it.
will you have a slightly higher velocity, as opposed to shooting from the hip, where recoil will push your rifle back
Link Posted: 11/20/2008 2:26:48 PM EDT
[Last Edit: 11/20/2008 2:27:08 PM EDT by thelastgunslinger]
yes.

slightly.
Link Posted: 11/20/2008 2:27:26 PM EDT
Yes. slightly.
Link Posted: 11/20/2008 2:28:36 PM EDT
In and awaiting watching on Mythbusters.........
Link Posted: 11/20/2008 2:32:55 PM EDT
[Last Edit: 11/20/2008 2:35:38 PM EDT by 57Strat]
Just curious. Has anyone ever tested the muzzle velocity of a semi-auto vs a bolt action, with the same length/twist barrel and identical ammo? Possibly a better test would be to test say...an FN FAL muzzle velocity with the gas port set to normal vs off. I wonder if cycling the action lowers the muzzle velocity.
Link Posted: 11/20/2008 2:33:47 PM EDT
Originally Posted By 57Strat:
Just curious. Has anyone ever tested the muzzle velocity of a semi-auto vs a bolt action, with the same length/twist barrel and identical ammo?



+1, always wanted to know this.
Link Posted: 11/20/2008 2:34:40 PM EDT
[Last Edit: 11/20/2008 2:37:24 PM EDT by DevilsAdvocate]
Your muzzle velocity will not change.

Well, it MIGHT change if you magically put a bigger charge of GP into the cartridge as the butt of the rifle touched the wall.

Your recoil will not change either. The wall just absorbs it.

And no, your muzzle velocity will not change if you shoot from a moving vehicle.

Link Posted: 11/20/2008 2:35:18 PM EDT
No.
Link Posted: 11/20/2008 2:36:40 PM EDT
Originally Posted By 57Strat:
Just curious. Has anyone ever tested the muzzle velocity of a semi-auto vs a bolt action, with the same length/twist barrel and identical ammo? Possibly a better test would be to test say...an FN FAL muzzle velocity with the gas port set to normal vs off. I wonder if cycling the action lowers the muzzle velocity.


Yes. A semi-auto is always going to be slightly slower than a comparable bolt gun.
Link Posted: 11/20/2008 2:36:59 PM EDT
Originally Posted By Danner130:
No.




The laws of physics says it will. How much, I have no idea. Just a guess is a few fps.
Link Posted: 11/20/2008 2:38:02 PM EDT
turning off the gas port will increase your MV.

if it is enough to be statistically significant, I don't know.
Link Posted: 11/20/2008 2:38:47 PM EDT
Originally Posted By Capt-Planet:
Originally Posted By 57Strat:
Just curious. Has anyone ever tested the muzzle velocity of a semi-auto vs a bolt action, with the same length/twist barrel and identical ammo? Possibly a better test would be to test say...an FN FAL muzzle velocity with the gas port set to normal vs off. I wonder if cycling the action lowers the muzzle velocity.


Yes. A semi-auto is always going to be slightly slower than a comparable bolt gun.




I understand that the laws of physics says it will, but I was wondering if anyone has actually tested it.

Link Posted: 11/20/2008 2:38:59 PM EDT
[Last Edit: 11/20/2008 2:45:12 PM EDT by DevilsAdvocate]
Originally Posted By Capt-Planet:
Originally Posted By 57Strat:
Just curious. Has anyone ever tested the muzzle velocity of a semi-auto vs a bolt action, with the same length/twist barrel and identical ammo? Possibly a better test would be to test say...an FN FAL muzzle velocity with the gas port set to normal vs off. I wonder if cycling the action lowers the muzzle velocity.


Yes. A semi-auto is always going to be slightly slower than a comparable bolt gun.


Nope.

Originally Posted By RyJones:
turning off the gas port will increase your MV.

if it is enough to be statistically significant, I don't know.


Gas port setting has nothing to do with muzzle velocity, and if it did, it would be so miniscule an amount that it would be silly to care.

Your muzzle velocity in any weapon is only concerned with the amount of charge in the shell, and the length of the barrel. It would also be dependant on the weight of the bullet, but Im only assuming the testing would be using the exact same load combination every time.

Originally Posted By 57Strat:
Originally Posted By Danner130:
No.




The laws of physics says it will. How much, I have no idea. Just a guess is a few fps.


No it doesn't. He asked if putting the butt against the wall would increase the velocity. The answer is a simple "no".
Link Posted: 11/20/2008 2:41:03 PM EDT
Originally Posted By DevilsAdvocate:
Your muzzle velocity will not change.


I would have to disagree with that statement. I have fired a lot of 22lr through a chrony and on a blow back action it has been my experience that muzzle velocity does change. I will try it again on a 10/22 which has a bolt that can easily be held forward and get back to you.
Link Posted: 11/20/2008 2:49:55 PM EDT
[Last Edit: 11/20/2008 2:56:53 PM EDT by DevilsAdvocate]
Originally Posted By oldcatdriver:
Originally Posted By DevilsAdvocate:
Your muzzle velocity will not change.


I would have to disagree with that statement. I have fired a lot of 22lr through a chrony and on a blow back action it has been my experience that muzzle velocity does change. I will try it again on a 10/22 which has a bolt that can easily be held forward and get back to you.


.22 ammo is not a good round for this test. You need to use perfectly measured handloads to get any real results.

Now, you also have a blow-back action, which, in some cases MAY clear the breach before the bullet gets to the end of the barrel...but in MOST cases the bullet is gone before the shell clears the breech...This is simply proven by the fact that you don't get burned every time you shoot a gun.

I'm sure that someone can find a slo-mo shot of an automatic being fired...It's a good guess that most breeches do not open until the bullet is long gone...I will go look for one.

http://www.youtube.com/watch?v=UBC12v_4cNY

Ok...Watch the action here....If the bullet was still in the barrel, barrel pressure would still be quite high, resulting in hot gaseous crap coming out through the breech....But there is not because the bullet has already left the gun...The ejection probably started just as the bullet was leaving.
Link Posted: 11/20/2008 2:54:24 PM EDT
Originally Posted By DevilsAdvocate:
Originally Posted By Capt-Planet:
Originally Posted By 57Strat:
Just curious. Has anyone ever tested the muzzle velocity of a semi-auto vs a bolt action, with the same length/twist barrel and identical ammo? Possibly a better test would be to test say...an FN FAL muzzle velocity with the gas port set to normal vs off. I wonder if cycling the action lowers the muzzle velocity.


Yes. A semi-auto is always going to be slightly slower than a comparable bolt gun.


Nope.

Originally Posted By RyJones:
turning off the gas port will increase your MV.

if it is enough to be statistically significant, I don't know.


Gas port setting has nothing to do with muzzle velocity, and if it did, it would be so miniscule an amount that it would be silly to care.

Your muzzle velocity in any weapon is only concerned with the amount of charge in the shell, and the length of the barrel. It would also be dependant on the weight of the bullet, but Im only assuming the testing would be using the exact same load combination every time.

Originally Posted By 57Strat:
Originally Posted By Danner130:
No.




The laws of physics says it will. How much, I have no idea. Just a guess is a few fps.


No it doesn't. He asked if putting the butt against the wall would increase the velocity. The answer is a simple "no".



I disagree. On the wall scenario, normally, some of the energy that would propel the bullet is lost when the gun recoils. When the butt stock is place against an immovable object, that energy that was once the recoil is now used to propel the bullet slightly faster than if the gun were held normally.

With a semi-auto gun, the energy used to cycle the action would be used with a bolt action to propel the bullet. Again, providing a slightly higher velocity. I have no idea how much faster, but it would be faster.

Link Posted: 11/20/2008 3:01:55 PM EDT
Originally Posted By 57Strat:
Originally Posted By DevilsAdvocate:
Originally Posted By Capt-Planet:
Originally Posted By 57Strat:
Just curious. Has anyone ever tested the muzzle velocity of a semi-auto vs a bolt action, with the same length/twist barrel and identical ammo? Possibly a better test would be to test say...an FN FAL muzzle velocity with the gas port set to normal vs off. I wonder if cycling the action lowers the muzzle velocity.


Yes. A semi-auto is always going to be slightly slower than a comparable bolt gun.


Nope.

Originally Posted By RyJones:
turning off the gas port will increase your MV.

if it is enough to be statistically significant, I don't know.


Gas port setting has nothing to do with muzzle velocity, and if it did, it would be so miniscule an amount that it would be silly to care.

Your muzzle velocity in any weapon is only concerned with the amount of charge in the shell, and the length of the barrel. It would also be dependant on the weight of the bullet, but Im only assuming the testing would be using the exact same load combination every time.

Originally Posted By 57Strat:
Originally Posted By Danner130:
No.




The laws of physics says it will. How much, I have no idea. Just a guess is a few fps.


No it doesn't. He asked if putting the butt against the wall would increase the velocity. The answer is a simple "no".



I disagree. On the wall scenario, normally, some of the energy that would propel the bullet is lost when the gun recoils. When the butt stock is place against an immovable object, that energy that was once the recoil is now used to propel the bullet slightly faster than if the gun were held normally.

With a semi-auto gun, the energy used to cycle the action would be used with a bolt action to propel the bullet. Again, providing a slightly higher velocity. I have no idea how much faster, but it would be faster.



The only energy that propels the bullet is the explosive charge.

The energy from the recoil was absorbed by the wall...I will bet good money that the area on the wall that was used now has a SLIGHTLY higher temperature... because I can guarantee you that recoil did NOT decide to "go forward and assist the bullet speed".

Look at the movie above...the explosive energy is used and almost gone by the time the bolt even starts to move backward....because the explosive gasses in the barrel have already done their job and the bullet is already gone.
Link Posted: 11/20/2008 7:32:32 PM EDT
Originally Posted By ag04blast:
In and awaiting watching on Mythbusters.........


not sure if i trust those guys to do the test with out mucking it up
Link Posted: 11/20/2008 7:34:41 PM EDT
Are you firing the gun on a treadmill?
Link Posted: 11/20/2008 7:52:24 PM EDT
I was using the same ammo out of a 10 22 and a Remington 510 and penetration trough a metal coffee can was drastically different.
Link Posted: 11/20/2008 8:27:44 PM EDT
I know if you put a canon against a wall so there isn't any give it can blow up
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